Dissertations / Theses: 'Mirabilis'

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Charles, Ian George. "Proteus mirabilis and cat." Thesis, University of Leicester, 1986. http://hdl.handle.net/2381/35192.

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Proteus mirabilis PM13 is a well characterized chloramphenicol-sensitive isolate which spontaneously gives rise to resistant colonies on solid media containing chloramphenicol (50ug/ml) at a plating efficiency of between 10-4 and 10-5 per cell per generation. When a chloramphenicol resistant colony is grown in liquid medium in the absence of the antibiotic for I50 generations a population of predominantly sensitive cells arises. The cat gene responsible for the phenomenon is chromosomal, and has been cloned from P.mirabilis PMI3 with DNA prepared from cells grown in the absence or the presence of chloramphenicol. Recombinant plasmids which confer resistance to chloramphenicol carry an 8.5-kb PstI fragment irrespective of the source of host DNA. The location of The cat gene within the PstI fragment was determined by Southern blotting with a cat consensus 'active - site' oligonucleotide (5'-CCATCACAGACGGCATGATG-3') corresponding to the expected amino acid sequence of the active site region of chloramphenicol acetyltransferase. DNA sequence analysis has revealed a high degree of homology between the P. mirabllls cat -gene and the type I ca-t variant (Tn9), 76% at the amino acid level and 73% when nucleotides in the coding sequence are compared. The mechanism for the appearance and disappearance of chloramphenicol resistance in P. mirabilis appears to be associated with a host-specific trans-acting element which controls cat gene expression. A precedent for such a control network is given by phase variation in Salmonella typhimurium, where an invertible DNA segment controls the transcription of a trans-acting regulatory element. A comparison of the 5' regions of the S.typhimurium flagellin genes in and H2, which are alternately expressed by a flip-flop control mechanism with the 5' region of P.mirabilis cat show blocks of homology. Whether or not this homology is significant in the regulation of cat gene expression has not been determined.

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Toptchieva, Anna A. "Tellurite resistance of Proteus mirabilis." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0016/NQ49293.pdf.

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Michelim, Lessandra. "Abordagem biotecnológica em Proteus mirabilis." reponame:Repositório Institucional da UCS, 2008. https://repositorio.ucs.br/handle/11338/364.

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O gênero Proteus é caracterizado pela rápida mobilidade, fenômeno denominado swarming . Quanto à homologia de seu DNA, apresenta apenas uma discreta relação com o da Escherichia coli. Freqüentemente relacionado com infecções urinárias, facilitadas pela sua capacidade em degradar uréia, tem sido encontrado colonizando cateteres e sondas vesicais, principalmente a espécie Proteus mirabilis. Devido a sua crescente importância na prática clínica, tanto como agente infeccioso de difícil erradicação, quanto como microrganismo com possibilidade de produzir β-lactamases de espectro expandido, seu controle no ambiente hospitalar tornou-se essencial. A necessidade da correta identificação dessa bactéria estimulou com que métodos de identificação molecular sejam constantemente estudados e aprimorados para essa finalidade. Métodos baseados em PCR têm se mostrado úteis, mas precisam ser validados para a rotina laboratorial. Diversos fatores de patogenicidade, ou seja, características biológicas de Proteus que favorecem a sua participação em processos infecciosos têm sido identificados, tais como: a capacidade de mobilidade e fixação celular, produção de protease, urease e hemolisina. Diversos autores inferem que a correta co-regulação desses fatores de virulência durante a diferenciação de swarming está relacionada com a capacidade de colonizar e invadir o tecido do hospedeiro. Vários estudos sugerem que extratos vegetais podem ser importantes produtos no controle de P. mirabilis ao interferir em sinais de quorum sensing , e consequentemente, na diferenciação celular e expressão de fatores de virulência. Neste sentido, os terpenos, compostos presentes em óleos essenciais, podem representar uma alternativa viável no controle de infecções por esses microrganismos. As proteases microbianas vêm se destacando como importantes fatores de virulência devido a ação direta sobre proteínas do hospedeiro, particularmente imunoglobulinas. O estudo em P. mirabilis tem sido focalizado na protease ZapA (mirabilisina), enzima capaz de degradar IgA, IgG, entre outras proteínas. Trabalhos relatam que não somente ZapA é regulada durante o swarming , mas também hemolisinas, fatores ligados à diferenciação celular e hiperprodução do flagelo. Assim sendo, na presente tese foram avaliados distintos sistemas via PCR (RAPD, ERIC-PCR, REP-PCR, BOX-PCR e ISSR) para caracterização molecular de isolados clínicos de P. mirabilis, o efeito de monoterpenos sobre a diferenciação celular e a produção de fatores de patogenicidade dessas bactérias, e realizado um estudo bioinformático sobre o complexo de metaloproteases com base no recentemente publicado genoma de P. mirabilis.
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O gênero Proteus é caracterizado pela rápida mobilidade, fenômeno denominado swarming . Quanto à homologia de seu DNA, apresenta apenas uma discreta relação com o da Escherichia coli. Freqüentemente relacionado com infecções urinárias, facilitadas pela sua capacidade em degradar uréia, tem sido encontrado colonizando cateteres e sondas vesicais, principalmente a espécie Proteus mirabilis. Devido a sua crescente importância na prática clínica, tanto como agente infeccioso de difícil erradicação, quanto como microrganismo com possibilidade de produzir β-lactamases de espectro expandido, seu controle no ambiente hospitalar tornou-se essencial. A necessidade da correta identificação dessa bactéria estimulou com que métodos de identificação molecular sejam constantemente estudados e aprimorados para essa finalidade. Métodos baseados em PCR têm se mostrado úteis, mas precisam ser validados para a rotina laboratorial. Diversos fatores de patogenicidade, ou seja, características biológicas de Proteus que favorecem a sua participação em processos infecciosos têm sido identificados, tais como: a capacidade de mobilidade e fixação celular, produção de protease, urease e hemolisina. Diversos autores inferem que a correta co-regulação desses fatores de virulência durante a diferenciação de swarming está relacionada com a capacidade de colonizar e invadir o tecido do hospedeiro. Vários estudos sugerem que extratos vegetais podem ser importantes produtos no controle de P. mirabilis ao interferir em sinais de quorum sensing , e consequentemente, na diferenciação celular e expressão de fatores de virulência. Neste sentido, os terpenos, compostos presentes em óleos essenciais, podem representar uma alternativa viável no controle de infecções por esses microrganismos. As proteases microbianas vêm se destacando como importantes fatores de virulência devido a ação direta sobre proteínas do hospedeiro, particularmente imunoglobulinas. O estudo em P. mirabilis tem sido focalizado na protease ZapA (mirabilisina), enzima capaz de degradar IgA, IgG, entre outras proteínas. Trabalhos relatam que não somente ZapA é regulada durante o swarming , mas também hemolisinas, fatores ligados à diferenciação celular e hiperprodução do flagelo. Assim sendo, na presente tese foram avaliados distintos sistemas via PCR (RAPD, ERIC-PCR, REP-PCR, BOX-PCR e ISSR) para caracterização molecular de isolados clínicos de P. mirabilis, o efeito de monoterpenos sobre a diferenciação celular e a produção de fatores de patogenicidade dessas bactérias, e realizado um estudo bioinformático sobre o complexo de metaloproteases com base no recentemente publicado genoma de P. mirabilis.

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Nitzsche, Rainar. "Beutefang und "Brautgeschenk" bei der Raubspinne Pisaura mirabilis (CL.)(Araneae: Pisauridae) /." Kaiserslautern : Nitzsche, 2006. http://deposit.d-nb.de/cgi-bin/dokserv?id=2843137&prov=M&dok_var=1&dok_ext=htm.

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Walker, Cristiani Isabel Banderó. "MIRABILIS JALAPA L. Atividade Farmacológica e Citotóxica." Universidade Federal de Santa Maria, 2007. http://repositorio.ufsm.br/handle/1/5894.

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The family Nyctaginaceae consist of approximately 30 genus and 14 species. In Brazil, 10 genus and 70 species are found. The genus Mirabilis belongs this family and can be found spread worldwide. This plant popularly known as maravilha or bonina and it is used in folk medicine to treat infection, inflammation and pain. The plant was collected in March 2006 in Santa Maria (RS). Ethanolic extract (70%) was made by maceration and fractionated using organic solvents with increasing polarity (hexanic, dichloromethane, ethyl acetate and butanolic). Through qualitative chemical analysis it was found in greater quantity alkaloids, amino groups, sterols and/or triterpenoids, hidroxiantraquinones, anthocyanic pigments, volatile acids and phenols. In relation to the antimicrobial activity, the best response was obtained for the fraction dichloromethane from stem and the ethyl acetate from leaves for S. aureus and the fraction ethyl acetate from stem and leaves for S. cerevisiae. The higher concentration of phenolic compounds was found in the ethyl acetate fraction from leaves (7,45 mg/g drug). Through the method of DPPH, all samples showed antioxidant activity by TLC and by spectrophotometry. Ethyl acetate and butanolic fractions from leaves showed excellent antioxidant activity with IC50 of 20,40 μg/ml and 25,41 μg/ml, respectively. The highest content of quercetin was found in the leaves extract (0,19%). The ethyl acetate fraction produced analgesic activity reaching 82.8±7.9% inhibition in the writhing test. The hexanic fraction from leaves expressed the best toxicity front of Artemia (LC50 = 1.27 μg/ml)
A família Nyctaginaceae compreende aproximadamente 30 gêneros e 400 espécies. No Brasil são encontrados 10 gêneros e 70 espécies. O gênero Mirabilis está inserido nesta família e encontra-se amplamente distribuído por todo o mundo. Conhecida popularmente como bonina ou maravilha, é utilizada na medicina popular para o tratamento de infecções, inflamações e dores. A planta foi coletada em março de 2006 no município de Santa Maria (RS). O extrato bruto em etanol (70%) foi preparado por maceração e fracionado com solventes orgânicos de polaridade crescente (hexano, diclorometano, acetato de etila e butanol). Através da análise química qualitativa foram encontrados em maior quantidade heterosídeos antociânicos, alcalóides, amino-grupos, ácidos voláteis, esteróides e/ou triterpenos, hidroxiantraquinonas, e fenóis. Quanto à atividade antimicrobiana, as melhores respostas obtidas foram para a fração diclorometano do caule e folhas frente a S. aureus e a fração acetato de etila do caule e das folhas frente a S. cerevisiae. A maior concentração de compostos fenólicos foi encontrada na fração acetato de etila das folhas (7,45 mg/g de droga). Através do método do DPPH, todas as amostras mostraram atividade antioxidante por CCD e pelo método espectrofotométrico, sendo que as frações acetato de etila e butanólica das folhas demonstraram excelente atividade antioxidante com CI50 de 20,40 μg/ml e 25,41 μg/ml, respectivamente. O maior teor de quercetina foi encontrado no extrato das folhas (0,19%). A fração acetato de etila apresentou a maior atividade analgésica (I% = 82.8) no teste de contorções abdominais. A fração hexânica das folhas expressou a melhor toxicidade frente a Artemia salina (CL50=1,27 μg/ml).

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Aquilini, Eleonora. "Lipopolysaccharide (LPS) core biosynthesis in "Proteus mirabilis" / Estudio de la biosíntesis del núcleo de lipopolisacarido (LPS) en "Proteus mirabilis"." Doctoral thesis, Universitat de Barcelona, 2013. http://hdl.handle.net/10803/98348.

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Urinary tract infection (UTIs) is an extremely common disease. Proteus mirabilis is a common cause of UTI in individuals with functional or structural abnormalities or with long-term catheterization, it forms bladder and kidney stones as a consequence of urease-mediated urea hydrolysis. Known virulence factors, besides urease, are flagella, fimbriae, outer membrane proteins, hemolysins, amino acid deaminase, protease, capsule and lipopolysaccharide (LPS). Study of LPS core is particularly relevant for several reasons: it is a conserved region, although it is increasingly clear that there is some variability at the genus or groups of similar genera, its chemical structure modulates the endotoxic activity of lipid A, alteration of the LPS core, which generates less virulent bacteria, encourages the search of substances that interfere with the biosynthesis of this region, and conserved regions of the core LPS could be useful as antigens in preventing diseases caused by pathogens that contain these conserved regions. The specific aims of this project have been to identify and functionally characterize genes involved in core LPS biosynthesis in P. mirabilis, to elucidate the mechanism of incorporation of galactosamine (GalN) to the core LPS, to identify genes coding for phosphoethanolamine (PEtN) modifications, and to characterize and to study the biological effects of the gene encoding the PEtN transferase involved in the modification of the second heptose residue (L,D-HepII). We found that P. mirabilis has most of the genes for the biosynthesis of LPS core grouped in the waa cluster in the chromosome. Despite this, additional genes required for core LPS biosynthesis are found outside the waa cluster. The pentasaccharide of the inner core, shared by all Enterobacteriaceae, is biosynthesized in P. mirabilis, by the sequential activity of a bifunctional transferase (WaaA) and three heptosyltransferases (WaaC, WaaF, and WaaQ). These enzymes are transcribed from genes located inside the waa cluster, and are conserved in P. mirabilis strains analyzed; for more, they show a high identity and similarity level to homologues proteins of Escherichia coli, Klebsiella penumoniae and Serratia marcescens. The waaL gene, coding for the O-antigen polymerase ligase, is found adjacent to the classic waa cluster. Downstream this gene, four genes encoding enzymes belonging to the 4 (walM, walN, and WalR), and 9 (walO) glycosyltransferase family were found. Even if members of these families were related to LPS core biosynthesis in several Gram-negative bacteria, in P. mirabilis they do not appear to be involved in the biosynthesis of the reported core LPS structures. The presence of the disaccharide hexosamine (HexN)-1,4-galacturonic acid (GalA) is a feature of P. mirabilis LPS outer core. Depending on the nature of the HexN outer core residue, two different homologues for N-acetyl-hexosamine transferases are present in the waa cluster: wabH or wabP. Altought the incorporation of glucosamine into LPS core requires an acetylglucosaminyltransferase (WabH) and a deacetilase (WabN), the incorporation of GalN requires three enzymes: an acetylgalactosaminyltransferase (WabP), a deacetilase (WabN) and an epimerase (gne). An amplification test with specific primers for this two different homologues can be used to predict the HexN nature in P. mirabilis LPS cores. The strain-specific genes wamB and wamC code for a galactosyltransferase and a heptosyltransferase respectively in strain R110 of P. mirabilis. The enzyme encoded by gene wamD is a N-acetylglucosaminyltransferase, and it is found in strain 51/57 of P. mirabilis. WamA, coded by wamA gene in the waa cluster of strains R110, 50/57, TG83 and HI4320, is a heptosyltransferase responsible for the incorporation of a quarter residue of heptose (Hep), in DD configuration, to the GalA II of the outer core. In P. mirabilis strain 51/57, a gene coding a protein of the Mig-14 family was identified inside the waa cluster, this localization appears to be an exception in the Enterobacteriaceae family. Inspection of the whole genome of P. mirabilis HI4320 did not allow the identification of a mig-14 similar gene. There are three putative PEtN transferases in the genome of P. mirabilis: PMI3040, PMI3576, and PMI3104. The gene identified as eptC (PMI3104) transfers the moiety of PEtN to the O-6 position of L,D-Hep II (HepII6PEtN). The absence of the positive charge due to PEtN residue doesn't affect the bacterial growth kinetics in lab conditions in rich or defined media, but causes a moderate destabilization of the outer-membrane. Despite the lack of the PEtN residue on the Hep II in P. mirabilis LPS core, has no statistically effects during urinary tract infection assays in mouse model, the absence of this modification causes an increase sensitivity to complement in non-immune human sera.
P. mirabilis no es una causa frecuente de infecciones urinarias en el huésped normal, más bien infecta el tracto urinario con alteraciones funcionales o anatómicas, o instrumentación crónica como el cateterismo. P. mirabilis está a menudo asociado con cálculos urinarios e incrustaciones de los catéteres y es, particularmente importante, en pacientes con cateterización prolongada. Las infecciones del tracto urinario asociadas a cateterización son mundialmente reconocidas como la causa más común de infección asociada a tratamientos en ambiente hospitalario. El LPS es un factor de virulencia importante en bacterias Gram negativas patógenas. También conocido como endotoxina, es una molécula glicolipídica que constituye la estructura mayoritaria de la cara externa de la membrana externa (OM). En Proteus mirabilis la mayoría de los genes responsables de la biosíntesis de núcleo de LPS están localizados en el cromosoma, en el agrupamiento génico waa. A pesar de esto, algunos genes adicionales, necesarios para la biosíntesis del núcleo de LPS, se encuentran ubicados fuera del agrupamiento génico waa. El pentasacárido del núcleo interno, común a todas las Enterobacteriáceae, se biosintetiza en P. mirabilis, por la actividad secuencial de una transferasa bifunciona (WaaA) y tres heptosiltransferasas (WaaC, WaaF, y WaaQ). La presencia del disacárido HexN‐1,4‐GalA es característica del núcleo externo de LPS en P. mirabilis. Dependiendo de la naturaleza del residuo de HexN, se encuentran, en el agrupamiento génico waa, dos HexNAc transferasas diferentes: wabH o wabP. El gen eptC (PMI3104) codifica para la enzima que transfiere el residuo de fosfoetanolamina a la posición O-6 de la L,D-Hep II (HepII6PEtN), en el núcleo de LPS de P. mirabilis. La ausencia de la carga positiva del residuo de fosfoetanolamina no afecta a la cinética de crecimiento de las bacterias en condiciones standard de laboratorio sea en medios ricos o definidos. La ausencia del residuo fosfoetanolamina provoca una desestabilización moderada de la membrana externa que se traduce en una disminución de la MIC para SDS.

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Broll, Valquiria. "Purificação e caracterização da urease recombinante de Proteus mirabilis." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2013. http://hdl.handle.net/10183/84981.

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Ureases são metaloenzimas dependentes de níquel, amplamente distribuída em bactérias, fungos e plantas. Estas enzimas atuam na catálise da hidrólise da ureia a amônia e dióxido de carbono. Proteus mirabilis é uma bactéria patogênica, produtora de urease, um de seus mais importantes fatores de virulência. Esta bactéria Gram-negativa se comporta como um uropatógeno oportunista responsável por severas infecções em pacientes hospitalizados. A amônia liberada pela hidrólise da ureia catalisada pela urease de Proteus mirabilis (PMU) causa um aumento no pH levando à formação de microclima, possibilitando a colonização do patógeno no trato urinário do hospedeiro. A PMU apresenta alta similaridade com outras ureases, como a urease de sementes de “Jack bean” (JBU) e a urease de Helicobacter pylori (HPU), para as quais nosso grupo descreveu diversas atividades biológicas que são independentes da hidrólise de ureia. Neste trabalho, nós produzimos PMU, e logo depois investigamos se esta, assim como a JBU e a HPU, apresenta atividades não relacionadas à atividade enzimática. As condições de cultivo para expressão da PMU expressa em Escherichia coli HB101 foram otimizadas pela metodologia de superfície de resposta. Concentrações de níquel, ureia e tempos de indução foram testados. A purificação da enzima recombinante foi obtida em 3 etapas cromatográficas. A primeira, uma HiTrapQTM HP (pH 7,5) onde a urease foi eluida com 400 mMol.L-1 de KCl. O pico das frações eluídas foram reunidas, dialisadas e aplicadas na coluna HiLoad 26/10 Q-SepharoseTM HP, usando o mesmo tampão e sal para eluição. As frações ativas foram novamente reunidas e a PMU foi submetida a cromatografia de gel filtração (Superdex 200TM 26/60-pg). A PMU apresenta estabilidade na faixa de pH 7,0 a 8,5, com seu pH ótimo estimado em 8,0. Alta atividade ureolítica pode ser detectada de 37 oC a 48 oC. Diferentes soluções salinas induzem o aumento na atividade enzimática desta urease, e quanto maior o tempo de exposição, maior a tendência a este aumento. Assim como a JBU, esta urease é capaz de inibir o crescimento de leveduras, mas diferentemente desta e da HPU, a PMU não apresenta atividade inibitória sobre a germinação de esporos e o crescimento de fungos filamentosos. As ureases de P. mirabilis e de H. pylori apresentam regiões de semelhança com o peptídeo proveniente do colágeno, e de acordo com testes de modelagem, esta região estaria exposta para interação com receptores localizados nas membranas de plaquetas, visto que ambas ativam plaquetas resultando na formação de agregados.
Ureases are Ni-dependent metalloenzymes, widespread in bacteria, fungi and plants, that catalyze the hydrolysis of urea into ammonium and carbon dioxide. The pathogenic bacteria Proteus mirabilis produces urease as virulence factor. Proteus mirabilis is a Gram negative opportunistic uropathogen, which causes severe infections in hospitalized patients. Ammonia released from urea hydrolysis by Proteus mirabilis urease (PMU) increases the local pH and forms a microclimate which allows the colonization of the host urinary tract. PMU presents high similarity to other ureases, such as that from Jack bean seeds (JBU) or from Helicobacter pylori (HPU), for which our group has described biological activities unrelated to urea hydrolysis. Here we aimed to investigate whether PMU shares with JBU and HPU other properties unrelated to enzyme activity. Growth conditions of PMU-expressing Escherichia coli HB101 were optimized by response surface methodology prior to purification. Concentrations of nickel, urea, and induction time were tested. A partially purified recombinant enzyme was obtained after 3 chromatographic steps. In the first, a HiTrapQTM HP (pH 7.5), urease eluted with 400 mMol.L-1 KCl. Peak fractions were pooled, dialyzed and loaded in a HiLoad 26/10 Q-SepharoseTM HP column using same buffer and eluting salt. The active fractions were pooled and PMU was submitted to gel filtration (Superdex 200TM26/60-pg). The enzyme was stable in the range of pH 7.0 up to 8.5, with optimum pH at 8.0. The ureolitic activity is high from 37 oC up to 48 oC. Different salts increased the ureolytic activity of PMU, the longer the exposition, the higher was the increase in activity. PMU inhibited yeast growth, similarly to the effect induced by JBU. Differently from JBU and HPU, this urease did not inhibit spore germination and growth of different filamentous fungi. Ureases from P. mirabilis and H. pylori presented regions of homology with collagen, and according to modeling tests, these region are exposed to receptor recognition localized in platelets membrane, which might explain their platelet aggregating effect.

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Nitzsche, Rainar. ""Brautgeschenk" und Reproduktion bei Pisaura mirabilis, einschliesslich vergleichender Untersuchungen an Dolomedes fimbriatus und Thaumasia uncata (Araneida: Pisauridae)." Kaiserslautern Nitzsche, 1987. http://deposit.d-nb.de/cgi-bin/dokserv?id=2842652&prov=M&dok_var=1&dok_ext=htm.

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Ossolinski, Justin Emerson. "Carbon budget analysis of the branching coral Madracis mirabilis." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 96 p, 2007. http://proquest.umi.com/pqdweb?did=1338884351&sid=14&Fmt=2&clientId=8331&RQT=309&VName=PQD.

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Lai, Hsin-Chih. "Molecular studies on the swarming migration of Proteus mirabilis." Thesis, University of Cambridge, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321393.

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Fonseca, Marina Rocha Borges da. "Caracterização do fenótipo mutador de isolados de Proteus mirabilis." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/42/42132/tde-11052017-092822/.

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Cepas com altas taxas de mutação (mutadoras) foram detectadas em diversos gêneros bacterianos. A alta taxa de mutação está relacionada a defeitos em sistemas de reparo de DNA. Uma alta incidência de isolados clínicos de Proteus mirabilis com altas frequências de mutação foi descrita anteriormente. O fenômeno foi induzido em Escherichia coli, quando transformada com um plasmídeo de P. mirabilis. Com coleção de 77 isolados clínicos de P. mirabilis, medimos a frequência de mutantes espontâneos e verificamos a presença do elemento conjugativo ICE SXT/R391, para desvendar possível relação entre a presença do ICE e a frequência de mutação. 9 isolados clínicos apresentam o ICE. A frequência de mutantes mostrou que não existem mutadores verdadeiros, mas 11 isolados apresentam uma alta frequência de mutantes FosR. Considerando o alto índice de infecções por P. mirabilis, é importante entender a resistência à fosfomicina, já que esta é usada na clínica. Não existe relação entre uma frequência de mutantes espontânea e a presença de ICE SXT/R391 em isolados de P. mirabilis.
Strains with high mutation rates (mutators) were detected in several bacterial genera. The increased mutation rate is related to defects in DNA repair systems. A high incidence of Proteus mirabilis clinical isolates with high mutation frequencies were described previously. The phenomenon was induced in Escherichia coli, when transformed with a plasmid of P. mirabilis. 77 P. mirabilis clinical isolates were tested for the frequency of spontaneous mutants and the presence of a conjugative element found in this species, ICEs SXT/R391, to verify if there is a relation between the element and the mutation frequencies. 9 isolates carry the ICE SXT/R391. The frequency of mutants showed no true mutators among the isolates. 11 isolates show a high frequency of FosR mutants. Considering the high rate of infections by P. mirabilis, it is important to understand the fosfomycin phenomenon, since it is currently used to treat urinary infections. We have seen no relation between a high spontaneous mutation frequency and the presence of ICE SXT/R391 in isolates of P. mirabilis.

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Kraevska, Sofia. "Terra Mirabilis: A Composition for Symphony Orchestra in Three Movements." Scholarly Repository, 2009. http://scholarlyrepository.miami.edu/oa_dissertations/199.

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Terra Mirabilis is a three-movement musical composition for symphony orchestra with piano solo inspired by natural landscapes photographed by the composer. The three movement composition and its corresponding landscapes portray three times of a day: early morning (I. The Mists), evening (II. Oceanus), and late night (III. Nocturne). Each chapter is devoted to the discussion of one movement, wherein overall concept and form are addressed, followed by detailed analyses of harmonic structure, motivic and thematic development, orchestration, and representational elements. As a complement to the score and the text, a CD-R audio recording of orchestral mock-ups accompanies this dissertation.

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Stukes, James Bernard. "Interactions of Plasmid DNA with the membranes of proteus mirabilis." DigitalCommons@Robert W. Woodruff Library, Atlanta University Center, 1988. http://digitalcommons.auctr.edu/dissertations/1569.

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The interactions of plasmid DNA with the membranes of Proteus mirabilis has been investigated under in vitro conditions. Analysis of the endogenous plasmid, NR1, the compatible plasmid, R6K, and the incompatible plasmid, R6- 5, on 5-20% neutral sucrose gradients, following the in vitro binding assay revealed binding to inner and outer membrane preparations. In competition experiments, R6K did not compete with NR1 for binding site(s). However, R6-5 successfully competed with NR1. Furthermore, high salts (0.2 M KCl or MgC12) inhibited the binding of NR1, R6K, and R6-5 to the membranes of P. mirabilis. However, 5-20% gradients containing salts did not release plasmids from their bound templates. In addition, plasmid minus P. mirabilis membranes did not bind compatible nor incompatible plasmids. Restriction enzyme digested fragments did not bind to membrane fractions.

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14

Walker, Cristiani Isabel Banderó. "Avaliação do potencial antinociceptivo da Mirabilis jalapa L. em camundongos." Universidade Federal de Santa Maria, 2010. http://repositorio.ufsm.br/handle/1/4460.

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The knowledge about the use of medicinal plants by the population contributed decisively to the modern therapy and the discovery of important mechanisms related to the process of transmission and treatment of pain. A plant widely used in folk medicine is Mirabilis jalapa L. (Nyctaginaceae). The infusion of its leaves is used for the treatment of inflammatory and painful diseases; however, there are no studies confirming its popular use. In this study, we evaluated the potential antinociceptive effects of Mirabilis jalapa in mice. Oral administration (p.o.) of the crude hidroetanolic extracts from leaves and stems inhibited the nociception with ID50 values of 5.5 (2.3 to 13.1) and 18.0 (11.3 to 28.5) mg/kg in a model of acute pain induced by chemical stimulation (test of writhing induced by acetic acid). Among the fractions tested, the ethyl acetate fraction from the leaves (Eta, 10 mg/kg, p.o.) was more effective and potent to induce antinociception with ID50 value of 1.1 (0.6 to 2.1) mg/kg. Thus, this fraction was chosen for further studies. Furthermore, these extracts also inhibited the nociception induced by thermal stimulation (tail-flick test). In addition, Eta (10 mg/kg, p.o.) produced antinociception in models of pain related to arthritis (caused by Freund's Complete Adjuvant (CFA)), neuropathic pain (caused by partial sciatic nerve ligation) and post-surgical pain (induced by incision in the paw of mice). Only the repetead administrations of Eta (10 mg/kg, p.o.) cause a decrease in paw edema produced by CFA. The antinociceptive effect of Eta (10 mg/kg, p.o.) was not reversed by pretreatment with naloxone (2 mg/kg, i.p.), but by atropine (5 mg/kg, s.c.) or mecamylamine (0.001 mg/kg, s.c.). As the participation of the cholinergic system in antinociception was induced by this fraction, we determined the effect of Eta on the activity of acetylcholinesterase (AChE) in vitro and ex vivo. The in vitro activity of AChE in blood and spinal cord of animals was not altered by Eta (1 and 10 mg/mL). In the ex vivo assay, an increase of enzyme activity in the spinal cord of mice treated with CFA, which was completely reversed with the administration of Eta (10 mg/kg, p.o.), was observed. With regard to adverse effects, Eta (10 mg/kg, p.o.) did not alter locomotor activity, body temperature or gastrointestinal transit, nor produced gastric lesions. These results demonstrated that M. jalapa shows antinociceptive activity in mice, confirming its popular use as an analgesic.
O conhecimento sobre o uso de plantas medicinais pela população contribuiu decisivamente para a terapêutica moderna e para a descoberta de importantes mecanismos relacionados com o processo de transmissão e o tratamento da dor. Uma planta muito utilizada pela medicina popular é a Mirabilis jalapa L. (Nyctaginaceae). A infusão das suas folhas é utilizada para o tratamento de doenças inflamatórias ou dolorosas, mas ainda não existem estudos confirmando o seu uso popular. No presente trabalho, foi avaliado o potencial antinociceptivo da Mirabilis jalapa em camundongos. A administração oral (v.o.) dos extratos brutos hidroetanólicos das folhas e de caules foi efetiva em inibir a nocicepção com valor de DI50 de 5,5 (2,3 13,1) e 18,0 (11,3 28,5) mg/kg, em um modelo de dor aguda induzida por estímulo químico (teste das contorções abdominais induzidas por ácido acético). Entre as frações testadas, a fração acetato de etila obtida das folhas (Eta, 10 mg/kg, v.o.) foi a mais potente em induzir a antinocicepção com valor de DI50 de 1,1 (0,6 2,1) mg/kg. Por isso, esta fração foi escolhida para a realização de estudos posteriores. Além disso, esses extratos também inibiram a nocicepção induzida por estímulo térmico (teste da imersão de cauda). Em adição, a Eta (10 mg/kg, v.o.) produziu antinocicepção em modelos de dor relacionada a artrite (causada por Adjuvante Completo de Freund (ACF), dor neuropática (provocada pela ligação parcial do nervo ciático) e dor pós-cirúrgica (induzida por incisão na pata de camundongos). Somente a administração repetida da Eta provocou uma diminuição do edema de pata induzido por ACF. Entretanto, a Eta não alterou o aumento dos níveis de interleucina 1-β produzido por ACF. O efeito antinociceptivo da Eta (10 mg/kg, v.o.) não foi revertido pelo pré-tratamento com naloxona (2 mg/kg, i.p.), mas sim, por atropina (5 mg/kg, s.c.) ou mecamelamina (0,001 mg/kg, s.c.). Como houve a participação do sistema colinérgico na antinocicepção induzida por esta fração, foi determinado o efeito da Eta sobre a atividade da acetilcolinesterase (AChE) in vitro e ex vivo. A atividade in vitro da acetilcolinesterase no sangue e na medula espinhal dos animais não foi alterada pela Eta (1 e 10 μg/mL). Já no ensaio ex vivo, houve um aumento da atividade desta enzima na medula espinhal de camundongos tratados com ACF, que foi completamente revertida com a administração da Eta (10 mg/kg, v.o.). Com relação aos efeitos adversos, a Eta (10 mg/kg, v.o.) não alterou a atividade locomotora, temperatura corporal, trânsito gastrintestinal e nem produziu lesões gástricas. Estes resultados demonstraram que M. jalapa apresenta atividade antinociceptiva em camundongos, confirmando o seu uso popular como analgésico.

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15

Schultz-Ascensio, Eliette. "Diffusion d'îlots génomiques de multirésistance aux antibiotiques chez Proteus mirabilis." Thesis, Tours, 2018. http://www.theses.fr/2018TOUR3302/document.

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La résistance aux antibiotiques est une menace non négligeable pour la santé publique. Ces résistances peuvent être portées par différents supports dont les îlots génomiques. Il a été démontré que les îlots génomiques Salmonella Genomic Island 1 (SGI1) et Proteus Genomic Island 1 (PGI1) sont des acteurs importants de la multirésistance aux antibiotiques. Quelques variants de SGI1 et PGI1 ont déjà été décrits au sein de l’espèce P. mirabilis. Dans ce contexte, ce projet de thèse se proposait d’approfondir notre connaissance de la situation épidémiologique de la diffusion de SGI1 et PGI1 chez P. mirabilis chez l’homme et l’animal en France, en ce qui concerne la diversité des isolats, mais aussi celles des variants de SGI1/PGI1. En parallèle, une autre volonté a été d’identifier d’autres facteurs et acteurs permettant l’acquisition de gènes de résistances d’intérêt au sein des Morganellaceae (β-Lactamases à Spectre Etendu, céphalosporinase AmpC, Plasmid-mediated Quinolone Resistance...). Au final, cette étude a permis en outre de révéler les premiers cas de SGI1 et PGI1 chez P. mirabilis chez l’animal en France. De nouveaux variants de SGI1 ont également été mis en évidence. Et pour la première fois, SGI1 a été décrit chez M. morganii, une autre espèce d’entérobactérie
The antibiotic resistance is a major treat for public health. These resistances can be hold by different element and genomic islands are one of them. Salmonella Genomic Island 1 (SGI1) and Proteus Genomic Island 1 (PGI1) are important genetic elements for the antibiotic resistance. A few SGI1 and PGI1 variants were already described in P. mirabilis. It is in this context that this thesis project aimed to improve our knowledge about the epidemiological spread of SGI1 and PGI1 in P. mirabilis in humans but also in animals in France (diversity of isolates and SGI1/PGI1 variants). Moreover, another wish was to identify other factors and actors for the acquisition of antibiotic resistance in the Morganellaceae tribe (Extended-Spectrum β-Lactamases, AmpC cephalosporinase, Plasmid-mediated Quinolone Resistance…). Finally, this study revealed the first cases of SGI1 and PGI1 in P. mirabilis in animals in France. New SGI1 variants were also described. And for the very first time, SGI1 was found in M. morganii, another entrobacterial species

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16

Melo, Rafael Osti de. "Formação de biofilme em catéter urinário por Proteus mirabilis uropatogênico." Universidade Estadual de Londrina. Centro de Ciências Biológicas. Programa de Pós-Graduação em Microbiologia, 2010. http://www.bibliotecadigital.uel.br/document/?code=vtls000161576.

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Proteus mirabilis é a 3ª causa mais comum (depois de Escherichia coli e Klebsiella pneumoniae) de infecção do trato urinário complicada (causando 12% das infecções) e a segunda causa mais comum (depois de Providencia stuartii) de bacteriúria relacionada a cateter em grupos de pacientes com cateter de demora (15% de infecção). Essas infecções são conhecidas por serem freqüentemente persistentes, de difícil tratamento e até fatais, dependendo da severidade da doença nos pacientes. As complicações da infecção em pacientes cateterizados incluem o desenvolvimento de urolitíase, obstrução do trato urinário e de cateteres, formação de cálculos na bexiga e rins, e bacteriúria. P. mirabilis pode colonizar o cateter e formar biofilme tanto em sua superfície quanto em seu lúmen, e a atividade de sua urease libera amônia a partir da uréia, elevando o pH da urina. Sob estas condições alcalinas, precipitam-se cristais de estruvita e apatita os quais podem aderir ao biofilme. Com o desenvolvimento desse, o fluxo urinário no cateter pode ser obstruído causando incontinência, devido ao vazamento da urina sobre o cateter ou retenção de urina na bexiga a qual resulta em distensão dolorosa. O refluxo da urina infectada para os rins podem culminar em episódios de pielonefrite, septicemia e choque séptico. A presença do biofilme constitui ainda uma forma de defesa do microrganismo frente ao tratamento com antibióticos cuja ação seria normalmente eficaz em combater as infecções urinárias causadas por espécies de Proteus. Os objetivos do presente estudo incluem verificar a formação de biofilme por P. mirabilis em superfície abiótica, quantificar a capacidade e tempo de formação, estrutura e características do biofilme em cateter urinário na presença e ausência de urina.
The care of many patients undergoing long-term bladder catheterization is frequently complicated by infection with Proteus mirabilis. These organisms colonize the catheter, forming surface biofilm communities, and their urease activity generates alkaline conditions under which crystals of magnesium ammonium phosphate and calcium phosphate are formed and become trapped in the biofilm. As the biofilm develops it obstructs the flow of urine through the catheter, causing either incontinence due to leakage of urine around the catheter or retention of urine in the bladder. The aim of this study was to determine the characteristics P. mirabilis biofilm in urinary catheter in human urine and standard laboratory media. The structure of P. mirabilis HU49 (strongly adherent) and HU117 (nonadherent) biofilms were compared by scanning electron microscopy. Human urine biofilms were observed to form a crystalline structure at 24 h differently to the observed in biofilms produced in TSB. This study has demonstrated that two markedly different biofilm structures are formed, depending on the growth media utilized.

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Verdet, Charlotte. "Caractérisation de CMY-4, une nouvelle céphalosporinase plasmidique présente chez une souche tunisienne de Proteus mirabilis." Paris 5, 1999. http://www.theses.fr/1999PA05P049.

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18

Fraser, G. M. "Expression of flagella and haemolysin during swarming differentiation of P. mirabilis." Thesis, University of Cambridge, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.599189.

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A motile but non-swarming transposon mutant of P. mirabilis was phenotypically characterised and found to be defective in cell elongation and hyperexpression of cell surface flagella and HpmA toxin. The transposon had inserted into the 441bp flgN, a flagella gene of undefined function, cotranscribed in an operon with the Class 3 anti-σ²⁸ gene flgM. Flagella gene transcription was however not compromised in the mutant and as Class 3 genes were not strongly downregulated by FlgM feedback, the defect did not appear to lie in the membrane export machinery. Loss of FlgN reduced incorporation of flagellin into the membrane and caused release of unpolymerised FliC into the extracellular medium. The data suggest that FlgN facilitates acquisition of flagellin into filaments, a role that may be especially critical in attaining the threshold level of flagella required for swarming. Proteus FlgN was found to have leucine zipper-like motifs arranged on potential amphipathic helices, a feature conserved in cytosolic chaperones for the exported substrates of flagella-related type III virulence export systems. Expression of HpmA was investigated in wildtype P. mirabilis and in the flgN and FlhA flagellar gene mutants, both of which exhibit reduced swarm-specific haemolytic activity. Primer extension analysis of hpmBA genes revealed a differentially regulated σ⁷⁰ promoter upstream of hpmB and several potential transcription initiation or RNA processing sites upstream of hpmA. Northern blot analyses of full length, truncated and deleted transcripts indicated processing of the unstable full length hpmBA transcript to yield a stable hpmA transcript. Transcriptional fusions of hpmB and hpmA to the luxAB reporter genes strengthened the view that swarm-specific regulation of transcription initiation was centred on the region 5' of hpmB, and involved sequences 5' of the σ⁷⁰ promoter. The fusion analyses also indicated that repression of hpmBA transcription in the flagellar mutants could be relieved by truncation of the hpmB upstream region.

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19

Pumacahua, Ramos Augusto. "Extração e caracterização de amido de quinoa, cañihua e Mirabilis jalapa /." São José do Rio Preto, 2014. http://hdl.handle.net/11449/128118.

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Orientador: José Francisco Lopes Filho
Banca: Ivo Mottin Demiate
Banca: Egon Schnitzler
Banca: José Antonio Gomes Vieira
Banca: Vânia Regina Nicoleti Telis
Resumo: O objetivo principal deste trabalho foi extrair e caracterizar amidos de grãos de quinoa (Chenopodium quinoa Willd.), cañihua (Chenopodium pallidicaule Aellen) e maravilha (Mirabilis jalapa). Foram determinadas as isotermas de adsorção de grãos e amido de quinoa em diferentes temperaturas e umidades relativas e ajustadas aos modelos matemáticos de GAB, Peleg, Caurie, Ferro-Foltan, Smith e Halsey. Foram também determinadas as energias de ativação e os calores isostéricos de adsorção. Estudou-se o fenômeno de transferência de massa na hidratação dos grãos de quinoa em diferentes tempos e temperaturas pelo modelo da segunda lei de Fick, determinando as difusividades efetivas. A dependência da difusividade efetiva com relação à temperatura foi descrita pela relação do tipo Arrhenius. A extração dos amidos da quinoa e cañihua foi realizada por meio da moagem úmida e o amido da maravilha por separação mecânica. Os amidos foram caracterizados quanto a composição de amilose, tamanho e forma dos grânulos, rugosidade, cristalinidade relativa, resistência à temperatura, entalpias de gelatinização, propriedades de pasta e outras. Técnicas instrumentais como a microscopia eletrônica de varredura, microscopia de força atômica, difração de raios X, espectroscopia de infravermelho, espectrofotometria, termogravimetria, calorimetria diferencial exploratória, viscosimetria, analisador de tamanho de partículas foram usadas nas caracterizações dos amidos. Os resultados confirmaram estudos semelhantes e foram obtidas outras informações inéditas que podem ser usadas para uma melhor utilização dos grãos e amidos
Abstract: The main objective of this research was to extract and characterize starch grain of quinoa (Chenopodium quinoa Willd.), cañihua (Chenopodium pallidicaule Aellen) and marvel (Mirabilis jalapa). The moisture sorption isotherm data of grains and starch of quinoa were investigated at different temperatures and relative umidity and adjusted to mathematical models of GAB, Peleg, Caurie, Ferro-Foltan, Smith and Halsey. The activation energies and isosteric heats of adsorption were determined. It was investigated the phenomenon of mass transfer in quinoa grain hydration at different times and temperatures by Fick's second law model, and the effective diffusivity was calculated. Temperature dependence of the effective diffusivity was described by Arrhenius-type relationship. The extraction of starches from quinoa and cañihua was performed by wet milling and starch marvel by mechanical separation. The starches were characterized according to amylose composition, size and shape of the granules, roughness, relative crystallinity, heat resistance, gelatinization enthalpy, paste properties and others. Instrumental techniques such as scanning electron microscopy, atomic force microscopy, X-ray diffraction, spectroscopy infrared, spectrophotometry, thermogravimetry, differential scanning calorimetry, rapid viscoamylographic analysis, particle size analyzer were used in the characterization of starches. The results confirmed similar studies and other unpublished information were obtained that can be used to make better use of grains and starches
Doutor

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20

Pumacahua, Ramos Augusto [UNESP]. "Extração e caracterização de amido de quinoa, cañihua e Mirabilis jalapa." Universidade Estadual Paulista (UNESP), 2014. http://hdl.handle.net/11449/128118.

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O objetivo principal deste trabalho foi extrair e caracterizar amidos de grãos de quinoa (Chenopodium quinoa Willd.), cañihua (Chenopodium pallidicaule Aellen) e maravilha (Mirabilis jalapa). Foram determinadas as isotermas de adsorção de grãos e amido de quinoa em diferentes temperaturas e umidades relativas e ajustadas aos modelos matemáticos de GAB, Peleg, Caurie, Ferro-Foltan, Smith e Halsey. Foram também determinadas as energias de ativação e os calores isostéricos de adsorção. Estudou-se o fenômeno de transferência de massa na hidratação dos grãos de quinoa em diferentes tempos e temperaturas pelo modelo da segunda lei de Fick, determinando as difusividades efetivas. A dependência da difusividade efetiva com relação à temperatura foi descrita pela relação do tipo Arrhenius. A extração dos amidos da quinoa e cañihua foi realizada por meio da moagem úmida e o amido da maravilha por separação mecânica. Os amidos foram caracterizados quanto a composição de amilose, tamanho e forma dos grânulos, rugosidade, cristalinidade relativa, resistência à temperatura, entalpias de gelatinização, propriedades de pasta e outras. Técnicas instrumentais como a microscopia eletrônica de varredura, microscopia de força atômica, difração de raios X, espectroscopia de infravermelho, espectrofotometria, termogravimetria, calorimetria diferencial exploratória, viscosimetria, analisador de tamanho de partículas foram usadas nas caracterizações dos amidos. Os resultados confirmaram estudos semelhantes e foram obtidas outras informações inéditas que podem ser usadas para uma melhor utilização dos grãos e amidos
The main objective of this research was to extract and characterize starch grain of quinoa (Chenopodium quinoa Willd.), cañihua (Chenopodium pallidicaule Aellen) and marvel (Mirabilis jalapa). The moisture sorption isotherm data of grains and starch of quinoa were investigated at different temperatures and relative umidity and adjusted to mathematical models of GAB, Peleg, Caurie, Ferro-Foltan, Smith and Halsey. The activation energies and isosteric heats of adsorption were determined. It was investigated the phenomenon of mass transfer in quinoa grain hydration at different times and temperatures by Fick's second law model, and the effective diffusivity was calculated. Temperature dependence of the effective diffusivity was described by Arrhenius-type relationship. The extraction of starches from quinoa and cañihua was performed by wet milling and starch marvel by mechanical separation. The starches were characterized according to amylose composition, size and shape of the granules, roughness, relative crystallinity, heat resistance, gelatinization enthalpy, paste properties and others. Instrumental techniques such as scanning electron microscopy, atomic force microscopy, X-ray diffraction, spectroscopy infrared, spectrophotometry, thermogravimetry, differential scanning calorimetry, rapid viscoamylographic analysis, particle size analyzer were used in the characterization of starches. The results confirmed similar studies and other unpublished information were obtained that can be used to make better use of grains and starches

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21

Aniejurengho, Orode Uche Venitia. "Dendron-based synthetic bacteriophages for the treatment of Proteus mirabilis infections." Thesis, University of Brighton, 2016. https://research.brighton.ac.uk/en/studentTheses/0aa0ac9f-6b96-416b-9556-bcbf9a540290.

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In the last two decades a surge in antibiotic resistance has limited antibiotic effectiveness increasing the risk of uncontrolled epidemics especially for biofilm-related infections. The National Institute of Health reports that 80 % of human infections are biofilm related. The Proteus mirabilis bacteria were focused on in this study as they are significant biofilm formers in chronic infections such as biofilm-related urinary tract infections for which there are currently no completely effective treatment strategies. As biofilms can increase antibiotic resistance by up to 1000-fold, there is an urgent need for the development of novel antimicrobials. Thus, bacteriophages which are viruses that target and kill bacteria have been proposed as suitable alternatives, but factors like storage stability and re-isolation pose limitations. Towards investigating the development of new antimicrobial strategies, the aims of this thesis were to assess: (i) the therapeutic potential of bacteriophages against Proteus mirabilis biofilms and (ii) the development of a novel antimicrobial strategy based on a synthetic biology approach for improvement of bacteriophage-based biofilm control. The work presented in this thesis led to or may lead to four areas of development, which have the potential to contribute to fields of biofilm research, bioengineering and materials science. Firstly, novel bacteriophages against clinical strains of Proteus mirabilis were isolated with physicochemical and genomic characterisation. Unlike other studies, the effect of temperature was included in the selection of favourable bacteriophages for anti-biofilm use. Secondly, towards improving bacteriophage-based treatment, dendrimeric nanoparticles known as dendron were posed as alternatives, these were synthesised and characterised, and demonstrated improved biofilm reduction and eradication by 35 % and 100 % respectively compared with the most effective bacteriophage. Thirdly, this study developed insight into the dendron’s mechanism of action, which was previously unreported, and was proposed to be through disruption of Proteus mirabilis DNA systems. Fourthly, in a unique approach, the dendron was bioengineered with bacteriophage DNA using electrostatic interactions. The results suggested that the dendron has potential to be used as a carrier for bacteriophage DNA, and presents the first attempt in published literature at combining the anti-biofilm properties of bacteriophages and dendrons towards futuristic development of synthetic bacteriophages. The results also provide a promising antimicrobial strategy for use of dendrons as therapeutic agents, alone or in combination with antibiotics and bacteriophages for treatment of biofilm-related infections.

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22

Andreoletti, Pierre. "Etudes des relations structure/fonction de la catalase de la bactérie Proteus Mirabilis et de l'origine de la résistance aux péroxydes de la souche Proteus Mirabilis (PR)." Université Joseph Fourier (Grenoble), 2001. http://www.theses.fr/2001GRE10027.

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La catalase est une enzyme dont le role est d'eliminer l'eau oxygenee. Certaines catalases a heme utilisent le nadph et son mode d'action reste obscur. La catalase de proteus mirabilis (pmc) peut etre purifiee avec et sans nadph fixe. Les objectifs de ce travail etaient d'une part de mieux comprendre le mecanisme fonctionnel de la catalase et le role du nadph, en utilisant pmc comme enzyme modele, d'autre part d'identifier l'origine de la resistance a l'eau oxygenee du mutant pr de proteus mirabilis, qui a servi de source de pmc type sauvage. L'enzyme pmc recombinante surexprimee chez e. Coli presente la caracteristique d'incorporer de la protoporphyrine ix a la place de l'heme. Sa structure cristallographique (2 a de resolution) montre que la liaison a l'atome de fer n'est pas indispensable au repliement de l'enzyme. Neuf mutants ponctuels ont etes construits et exprimes chez e. Coli et leurs proprietes biochimiques ont ete comparees a celles de pmc, type sauvage. Le role des radicaux proteiques dans la reaction de la catalase avec les nucleotides a ete etudie grace aux mutants f194y et f215y dont les structures cristallographiques ont ete determinees a 2,11 a et 2,4 a de resolution. Dans le mutant f194y, on observe deux mecanismes, un mecanisme d'oxydation directe a deux electrons avec nadph et un mecanisme a un electron (type peroxydasique) declenche par la formation d'un radical tyrosyl avec nmnh. On peut en conclure que la reaction avec le nadph ne depend pas de la formation d'un radical tyrosyl sur l'enzyme. La diffusion de substrat et de produits dans la catalase a ete simulee par dynamique moleculaire. Les resultats montrent que seul le canal d'acces principal sert pour la circulation de ces molecules. Un mecanisme concernant la circulation de l'eau oxygenee, de l'eau et de l'oxygene au niveau du site actif est propose. L'analyse du mutant pr de p. Mirabilis montre que la resistance aux peroxydes est liee a la surexpression de la catalase et de deux ahpc.

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23

Bonnet, Richard. "Beta-lactamases de classe a chez les enterobacteriaceae : caracterisation de variants de tem et de deux nouveaux types enzymatiques ctx-m-8 et bes-1 (doctorat : microbiologie)." Clermont-Ferrand 1, 2000. http://www.theses.fr/2000CLF1MM12.

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24

Broughton, Sarah Louise. "Studies on the metabolism and O-acetylation of peptidoglycan in Proteus mirabilis." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ33213.pdf.

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25

Morgan, Sheridan David. "Study of the development of crystalline Proteus mirabilis biofilms on urinary catheters." Thesis, Cardiff University, 2007. http://orca.cf.ac.uk/54670/.

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Infection by Proteus mirabilis can seriously complicate the care of patients undergoing long-term indwelling bladder catheterisation. The urease-producing bacteria colonize the catheter surfaces forming extensive biofilm communities and are capable of generating ammonia from urea and elevating the pH of the urine and biofilm. Under these conditions crystals of calcium and magnesium phosphates form in the urine and within the bacterial biofilm on the indwelling device leading to its encrustation and blockage. Urine can leak around the outside of the blocked catheter and patients become incontinent. Alternatively, urine is retained within the bladder, causing painful distension of the bladder. Reflux of infected urine to the kidneys can lead to serious symptomatic episodes such as pyelonephritis, septicaemia and endotoxic shock. All available types of indwelling catheter are vulnerable to this problem and currently there are no effective procedures available for its control. While the basic mechanism has been established for catheter encrustation we still need to know more about some of the fundamental aspects of the process. Little is known about the early events and the precise mechanisms which P. mirabilis uses to colonize catheter surfaces. The factors that control the rate at which crystalline biofilm forms on the catheters are also unknown. The aims of this study were to establish the sequence of events in the early stages of crystalline P. mirabilis biofilm formation on the range of currently available catheters for use with patients to determine the role of Mannose-Resistant Proteus-hkc fimbriae (MR/P fimbriae) in P. mirabilis crystalline biofilm formation on catheters to investigate how the pH at which calcium and magnesium phosphates precipitate from urine, the nucleation pH (pHn) can be manipulated and to determine the effect of this parameter on the rate of catheter encrustation. Using a laboratory model of the catheterised bladder, scanning electron microscopy and X-ray microanalysis, the initial stages of P. mirabilis crystalline biofilm development was observed on catheter surfaces. All-silicone, silicone-coated latex, hydrogel-coated latex and hydrogel/silver-coated latex catheters rapidly acquired a microcrystalline 'foundation layer' comprised predominantly of calcium phosphate, upon which, P. mirabilis crystalline biofilm subsequently developed. A similar 'foundation layer' was observed on the encrusted surfaces of hydrogel/silver-coated catheters removed from long-term catheterised patients. The catheters impregnated with nitrofurazone briefly delayed the onset of crystalline biofilm formation, while all-silicone and hydrogel-coated latex catheters inflated with triclosan (3 mg/ml in Na2C03) were able to maintain acidic urine pH and prevent crystalline biofilm development for the 7 day experimental period. There is evidence that MR/P fimbriae are involved in initiating infection in non-catheterised urinary tracts. The role of these adhesins in crystalline biofilm formation on indwelling catheters however, has not been investigated. Using bladder models infected with a wild type P. mirabilis strain able to express MR/P fimbriae and its derived MR/P-negative mutant, time to catheter blockage experiments and scanning electron microscopy revealed that MR/P fimbriae were not essential for P. mirabilis colonization of catheter surfaces or the development of crystalline P. mirabilis biofilm. Although the wild type and mutant strain initiated biofilm formation in different ways both rapidly blocked all-silicone catheters with crystalline material. The overriding factor in catheter blockage was the generation of alkaline urine, raising the pH above that at which crystalline formations develop. Previously it has been demonstrated that the pHn of human urine can be elevated by dilution and by increasing its citrate content. In the present study the effect of dilution and adding citrate on the pHn of artificial was assessed. Furthermore, the effect on the rate of encrustation on all-silicone catheters was examined in laboratory models supplied with these urines and infected with urease-positive P. mirabilis, Providencia rettgeri and Proteus vulgaris. The pHn of urine could be elevated from pH 6.7 in neat urine to pH 8.4 in urine diluted to 1:6. When neat, 1:1, 1:2 and 1:3 diluted urines were supplied to bladder models significant increases in catheter lifespan were recorded at each ascending dilution. Increasing the citrate content of the 1:1 diluted urine from 0 to 3.0 g/L citrate elevated the pHn from pH 7 to pH 9.1. Scanning electron microscopy of catheter sections revealed crystalline material in the biofilms could be virtually eliminated for at least 7 days in models supplied with urine with pHns of >pH 8.5. Time to catheter blockage experiments showed the rate of catheter encrustation became significantly reduced as the pHn of urine increased. Catheters in models supplied with urine containing citrate concentrations of 1.5 mg/ml (pHn >8.4) or more drained freely for the whole 7-day experimental period.

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Stålhandske, Pia. "Male and female reproductive strategies in the nursery web spider : pisaura mirabilis /." Göteborg : Göteborg university, 2001. http://catalogue.bnf.fr/ark:/12148/cb39929322w.

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Camargo, Gabriela Maria Pavan de Arruda [UNESP]. "Avaliação de biofilme de proteus mirabilis em modelo experimental de fluxo dinâmico." Universidade Estadual Paulista (UNESP), 2006. http://hdl.handle.net/11449/103989.

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Universidade Estadual Paulista (UNESP)
O objetivo do presente trabalho foi o de verificar a formação de incrustações e o bloqueio do cateter de Foley utilizando-se um modelo laboratorial de bexiga humana. Para tanto, foram utilizadas duas urinas artificiais de diferentes composições: a) urina AS composta por dez solutos em concentrações semelhantes as encontradas na urina humana de 24 horas, acrescida de gelatina; b) urina AT composta por 4 solutos também encontrados na urina humana, mas em concentrações maiores e suplementada com ovalbumina de galinha. Também foi utilizada a urina de 24 horas de três homens. As urinas contaminadas com o P. mirabilis foram bombeadas (0,5ml/min) para o frasco em que o cateter estava inserido até a oclusão do cateter. A Microscopia Eletrônica de Varredura (MEV) foi utilizada para verificar a presença de biofilme nos segmentos dos cateteres. Foi observado uma diferença significante no peso dos segmentos dos cateteres após a canalização das urinas AS, AT e UH contaminadas com o P. mirabilis vs a canalização das urinas sem o microrganismo (p<0,05). O tempo de bloqueio dos cateteres que canalizaram a urina AS vs urina AT e UH vs urina AT também foram diferentes (p<0,05). O tempo de bloqueio dos cateteres, o número de células viáveis presentes no inóculo inicial e no momento do bloqueio do cateter, e variação no peso dos segmentos dos cateteres após a canalização com as urinas sem a adição do P. mirabilis e contaminadas com o P. mirabilis não foram diferentes para as urinas AS, AT e UH. As três urinas examinadas mostraram a estabilização do P. mirabilis e a manutenção em 108UFC/ml bem como a formação de biofilme. Os cateteres que canalizaram a urina AS e UH apresentaram tempos semelhantes de bloqueio. Os cateteres que utilizaram a urina AT foram bloqueados mais rapidamente (p<0,05). Não houve alteração de peso dos segmentos dos cateteres quando testados com o P. mirabilis entre as urinas.
The aim of the present work was to verify formation of encrustations and occlusion on Foley catheter using a laboratorial model of human bladder. Two artificial urines with different compositions were used: a) AS urine consisted by ten solutes in concentrations similar to those found in 24 hour human urine, added gelatin; b) AT urine consisted by four solutes, also found in human urine but in higher concentrations, and supplemented with chicken ovalbumin and UH 24 hour urine of three men. Urines contaminated with P. mirabilis were pumped (0,5ml/min) to flasks where the catheter was inserted reaching catheter occlusion. Scanning Electronic Microscopy (SEM) was used to check the presence of biofilms in catheter segments. The period of catheter occlusions after canalization was determined with the three urines, as well as the number of P. mirabilis viable cells present in the initial inoculum and in the end of the experiment. The period CFU/ml as well as biofilm formation. Catheters that canalized AS and HU urines showed similar occlusion periods. Catheters using AT urine were occluded faster (p<0.05). of catheter occlusions, the number of viable cells present in the initial inoculum and in the moment of catheter occlusion, as well as the variation in catheter segment weights after canalization with urines without P. mirabilis addition and with contaminated urines were not different for AS, AT and HU urines. The three examined urines showed stabilization of P. mirabilis, maintenance of 108 There was no alteration in catheter segment weights when tested with P. mirabilis among urines.

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Camargo, Gabriela Maria Pavan de Arruda. "Avaliação de biofilme de proteus mirabilis em modelo experimental de fluxo dinâmico /." Araraquara : [s.n.], 2006. http://hdl.handle.net/11449/103989.

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Resumo: O objetivo do presente trabalho foi o de verificar a formação de incrustações e o bloqueio do cateter de Foley utilizando-se um modelo laboratorial de bexiga humana. Para tanto, foram utilizadas duas urinas artificiais de diferentes composições: a) urina AS composta por dez solutos em concentrações semelhantes as encontradas na urina humana de 24 horas, acrescida de gelatina; b) urina AT composta por 4 solutos também encontrados na urina humana, mas em concentrações maiores e suplementada com ovalbumina de galinha. Também foi utilizada a urina de 24 horas de três homens. As urinas contaminadas com o P. mirabilis foram bombeadas (0,5ml/min) para o frasco em que o cateter estava inserido até a oclusão do cateter. A Microscopia Eletrônica de Varredura (MEV) foi utilizada para verificar a presença de biofilme nos segmentos dos cateteres. Foi observado uma diferença significante no peso dos segmentos dos cateteres após a canalização das urinas AS, AT e UH contaminadas com o P. mirabilis vs a canalização das urinas sem o microrganismo (p<0,05). O tempo de bloqueio dos cateteres que canalizaram a urina AS vs urina AT e UH vs urina AT também foram diferentes (p<0,05). O tempo de bloqueio dos cateteres, o número de células viáveis presentes no inóculo inicial e no momento do bloqueio do cateter, e variação no peso dos segmentos dos cateteres após a canalização com as urinas sem a adição do P. mirabilis e contaminadas com o P. mirabilis não foram diferentes para as urinas AS, AT e UH. As três urinas examinadas mostraram a estabilização do P. mirabilis e a manutenção em 108UFC/ml bem como a formação de biofilme. Os cateteres que canalizaram a urina AS e UH apresentaram tempos semelhantes de bloqueio. Os cateteres que utilizaram a urina AT foram bloqueados mais rapidamente (p<0,05). Não houve alteração de peso dos segmentos dos cateteres quando testados com o P. mirabilis entre as urinas.
Abstract: The aim of the present work was to verify formation of encrustations and occlusion on Foley catheter using a laboratorial model of human bladder. Two artificial urines with different compositions were used: a) AS urine consisted by ten solutes in concentrations similar to those found in 24 hour human urine, added gelatin; b) AT urine consisted by four solutes, also found in human urine but in higher concentrations, and supplemented with chicken ovalbumin and UH 24 hour urine of three men. Urines contaminated with P. mirabilis were pumped (0,5ml/min) to flasks where the catheter was inserted reaching catheter occlusion. Scanning Electronic Microscopy (SEM) was used to check the presence of biofilms in catheter segments. The period of catheter occlusions after canalization was determined with the three urines, as well as the number of P. mirabilis viable cells present in the initial inoculum and in the end of the experiment. The period CFU/ml as well as biofilm formation. Catheters that canalized AS and HU urines showed similar occlusion periods. Catheters using AT urine were occluded faster (p<0.05). of catheter occlusions, the number of viable cells present in the initial inoculum and in the moment of catheter occlusion, as well as the variation in catheter segment weights after canalization with urines without P. mirabilis addition and with contaminated urines were not different for AS, AT and HU urines. The three examined urines showed stabilization of P. mirabilis, maintenance of 108 There was no alteration in catheter segment weights when tested with P. mirabilis among urines.
Orientador: Elisabeth Loshchagin Pizzolitto
Coorientador: Antonio Carlos Pizzolitto
Banca: Taís Maria Bauab
Banca: Beatriz Ernestina Cabilio Guth
Banca: Izabel Yoko Ito
Banca: José Vanderli Menani
Doutor

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29

Holling, Nina. "Elucidating the genetic basis for catheter blockage and encrustation in Proteus mirabilis." Thesis, University of Brighton, 2014. https://research.brighton.ac.uk/en/studentTheses/a3907cda-6629-4edb-a4eb-c7d8323d4dc9.

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Indwelling urethral catheters are the most commonly used medical devices and catheter associated urinary tract infections (CAUTIs) are one of the most common hospital acquired infections. Over 40% of CAUTIs in long-term catheterised patients may be caused by the bacterium Proteus mirabilis. Urease produced by this bacterium generates alkaline conditions by breaking down urea, leading to the formation of dense crystalline biofilm structures on catheter surfaces. This crystalline biofilm makes infections hard to treat and causes the blockage of the catheter lumen, resulting in the retention of infected urine leading to episodes of ascending urinary tract infections. The aim of this study was to identify genes and pathways involved in crystalline biofilm formation by P. mirabilis, in order to inform the development of novel strategies for prevention of catheter blockage. To accomplish this, a bank of random mini-Tn5 transposon mutants was constructed in the clinical isolate P. mirabilis B4. A total of 3840 transposon mutants were screened for phenotypic alterations in biofilm formation. A total of 575 mutants isolated exhibited altered biofilm formation, but comparable rates of growth to P. mirabilis B4 under assay conditions (310 biofilm enhanced; 265 biofilm deficient). The disrupted genes of a subset of 35 transposon mutants were successfully identified. After further phenotypic characterisation 12 transposon mutants were selected and their ability to encrust and block urethral catheters analysed using an in vitro model of the catheterised urinary tract (the bladder model). The bladder models yielded 4 transposon mutants with significant differences in the time taken to block catheters when compared to P. mirabilis B4. Two blocking deficient mutants were further analysed because these types of mutations are most likely to give insights relevant to the prevention of crystalline biofilm formation. Mutants STS8.1D7 and NHBFF9 were disrupted in aspects of the nitrogen metabolism and MFS family transport systems respectively. Timed bladder model experiments and chemical analysis of catheters of these mutants and the wild type B4 were then carried out to further evaluate the differences in crystalline biofilm formation. Overall, transposon mutants that took longer to block catheters displayed a lower level of encrustation after 10 h bladder model experiments. This was confirmed quantitatively by a significant reduction in calcium and biomass deposited onto catheters. Scanning electron microscopy (SEM) and environmental SEM (ESEM) further substantiated the quantitative methods illustrating clear differences in crystalline biofilm distribution for mutants that took longer to block catheters when compared to P. mirabilis B4. ESEM analysis optimized for this purpose allowed the examination of the crystalline biofilm ultrastructure in fine detail in its native, hydrated state and identified delicate calcium based crystal sheets which had not been visualised before. Additional flow chamber experiments confirmed that the ability of the two mutants to adhere to catheter biomaterials was not impaired, highlighting that the initial stages of biofilm formation were not associated with the genes disrupted for these mutants. Overall, the research conducted during this study identified 4 mutants differing in the time taken to block catheters, elucidating 4 genes that are involved in this complex phenotypic trait. Mutants with significant reductions in the ability to block urinary catheters displayed disruptions of the nitrogen metabolism and efflux systems which are believed to be involved in waste management in this bacterium. The inhibition of efflux systems in particular could be of potential value in the treatment or prevention of P. mirabilis crystalline biofilm formation by increasing its susceptibility to antimicrobials, and further investigation of these genes in the future could lead to the development of novel treatments for P. mirabilis CAUTIs.

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ROCHA, Laurimar Thomé da. "Importância da investigação farmacológica de Mirabilis jalapa Linn validação de sua utilização." Universidade Federal de Pernambuco, 2006. https://repositorio.ufpe.br/handle/123456789/3630.

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Mirabilis jalapa Linné, família das Nictagináceas, é uma planta herbácea ereta, profundamente ramificada, de folhas simples ovais, caule tipo haste, com flores pequenas, cálices apicais e pétalas que podem ser brancas, vermelhas, róseas, rôxas ou com tons multicoloridos. Nativa da América Tropical, sendo amplamente cultivada com fins decorativos no Brasil, onde é conhecida como bonina ou maravilha e encontrada da Bahia ao Paraná. Seu uso é difundido na medicina tradicional de muitos países para o tratamento de infecções, inflamação, edemas, conjuntivite, sendo também empregada como diurética, purgativa, tônica, antiespasmódica, vermífuga e antifúngica. Em sua composição fitoquímica relata-se a presença de alcalóides, flavonóides, triterpenóides e esteróides. Devido à diversidade do seu uso popular, buscou-se validar essas informações etnobotânicas, procurando dar suporte científico ao verificado na medicina tradicional. O trabalho teve como objetivo avaliar a toxicidade aguda e farmacológica (antiinflamatória e anti-tumoral em roedores) do extrato das folhas de Mirabilis jalapa em sua fração hexânica. Os ensaios de toxicidade aguda foram realizados por via intraperitoneal, com observações das respectivas alterações comportamentais para cada dose administrada. As doses utilizadas foram 1,0 a 3,0 g/kg, onde foram observados efeitos estimulantes nos primeiros 20 minutos após a administração do extrato hexânico e, em seguida, observados efeitos depressores. Efeitos como aumento da diurese e excreção fecal, foram relatados durante todo ensaio. A DL50 encontrada foi de 2009,167 mg/kg enquanto que a Concentração Letal (CL50) foi de 788,987 ug/ml, avaliada através de ensaio com Artemia salina Leach, o que permite sua classificação quanto à toxicidade em moderadamente tóxico. Em sua avaliação histopatológica, foram encontradas alterações como: congestão com áreas de necrose focal em fígado, congestão renal tubular, congestão e enfisema pulmonar. Para a atividade antiinflamatória utilizou-se o modelo de edema de pata induzido por carragenina, com a administração do extrato hexânico por via oral (125; 225 e 250 mg/kg) e por via intraperitoneal (62,5; 125; 225 e 250 mg/ kg), em ratas fêmeas. Nos ensaios antiinflamatórios, por via oral, não houve diminuição considerável dos volumes do edema da pata dos ratos, enquanto por via intraperitoneal, ocorreram inibições significativas somente na fase final da inflamação. A avaliação antitumoral do extrato hexânico de Mirabilis jalapa Linn frente ao Sarcoma 180 e Carcinoma de Ehrlich por via intraperitoneal (100; 125; 225 e 250 mg/kg) apresentou significativa redução do peso médio dos tumores dos grupos tratados, com índices relevantes de inibição tumoral. Os estudos histopatológicos revelaram foram as seguintes alterações: congestão hepática, atrofia da polpa branca no baço, enfisema pulmonar e atrofia glomerular nos rins, além da presença de metástases principalmente, nos grupos controle e nas doses menos concentradas

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31

Michalet, Serge. "Mirabilis jalapa L. (Nyctaginaceae) et modulation de la résistance bactérienne aux antibiotiques." Université Joseph Fourier (Grenoble), 2007. http://www.theses.fr/2007GRE10015.

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Le contrôle des infections par des bactéries pathogènes multi-résistantes, représente à l'heure actuelle, un enjeu primordial pour la santé publique, mondialement parlant. La rapidité de l'émergence de ces souches, due entre autres à l'utilisation massive et parfois mal contrôlée des antibiotiques, contraint les compagnies pharmaceutiques à adopter de nouvelles stratégies anti-infectieuses. Parmi ces dernières, l'utilisation d'inhibiteurs des pompes à efflux bactériennes, en association avec des antibiotiques efflués par ces pompes, est une perspective intéressante dans la mesure où cette thérapie combinatoire (association inhibiteur de la résistance + antibiotique) permettrait de prolonger et/ou d'améliorer l'utilisation en thérapeutique d'agents déjà existants. Dans ce contexte, l'étude phytochimique de Mirabilis jalapa Linn. (Nyctaginaceae) a conduit à l'isolement d'un composé actif, la N-trans-féruloyl 4'-O-méthyldopamine. La synthèse de dérivés de cette amide aromatique a permis de mettre en évidence des composés présentant des activités inhibitrices de la pompe NorA de Staphylococcus aureus, comparables à celle de l'alcaloïde de référence, la réserpine
The control of infectious diseases due to multiresistant pathogenic bacteria, is of primary concern for public health worldwide. The emergence rapidity of restistant strains, due to antibiotics mis use among others, prompts pharmaceutical companies to adopt new anti-infective strategies. Among them, the use of efflux pump inhibitors, in association with extruded antibiotics, is a promising approach as this combinatory therapy (antibitioc + resistance inhibitor association) would be a way to extend and/or improve the efficacy of existing agents. Ln this context, the phytochemical study of Mirabilis jalapa Linn. (Nyctaginaceae) led to the isolation of an active compound, namely N-trans-feruloyI4'-O-methyldopamine. Synthesis of derivatives ofthis aromatic amide let us access potent inhibitors, that showed inhibitory activities of the NorA efflux pump of Staphylococcus aureus, comparable to that of the standard alcaloïd reserpine

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32

Onaolapo, Josiah A. "The effect of R-plasmid RP1 on the properties of Proteus mirabilis." Thesis, Aston University, 1986. http://publications.aston.ac.uk/12455/.

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A clinical isolate of Proteus mirabilis containing R-plasmid RP1 (R+ cells), grown in both iron- and carbon- limited chemically defined media in mixed culture with plasmid-free (R- cells), did not disappear as expected, due to adherence of R+ cells to the wall of the chemostat vessel. Plasmid RP1 promoted adherence to glass and to medical prostheses. The hydrophobicity and surface charge of R+ cells were different from those of R- cells and both factors may contribute to the adherence of R+ cells to surfaces. The mode of cultivation of the cells, whether batch or continuous culture, were also found to affect the result. Antibodies raised against homologous cells increased the surface hydrophobicity of both R+ and R- cells and eliminated the differences between them. Results for surface hydrophobicity varied with the method used for measuring it. R+ cells were more sensitive than R- cells to tbe bacteridical action of normal serum and whole blood and to phagocytosis as measured by chemiluminescence. No clear differences were revealed in the protein antigens of R+ and R- cells by both SDS PAGE gels and immunoblots reacted with homologous antibodies. However, lectins revealed differences in the sugars exposed on the cell surfaces. Chemical analysis of R&43 and R- cells also revealed differences in the content of 2-keto-3-deoxy-D-manno-2-octulosonate, lipopolysaccharide and total fatty acids, when cells were grown in media containing added iron; however, no qualitative differences in the lipopolysaccharide were found. Removal of iron from the medium was found to have considerable effects on the chemical structure of R+ cells but not of R- ones. Adhesion to prostheses and to leucocytes is discussed in the light of the results and the clinical relevance outlined with respect to the initiation of infection and the association of virulence with antibiotic resistance.

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33

Reiter, Noushka Hedy, and noushka reiter@dse vic gov au. "Borya mirabilis steps in the recovery of a critically endangered Australian native plant." RMIT University. Applied Sciences, 2009. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20090227.160625.

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Borya mirabilis is one of the world's most critically endangered plants. The research in this thesis has illuminated key aspects of: its reproductive biology; interspecies and intraspecies molecular relationships, mycorrhizal status, tissue culture potential and disease threats. Each of these aspects has fundamental management implications for the active management of B. mirabilis. Floral observations of B. mirabilis and related species affirmed the uniqueness of the Boryaceae amongst the Asparagales. B. mirabilis had an unusually high number of floral abnormalities compared with other species of Borya observed. B. mirabilis is fly-pollinated. Pollen of Borya species showed little difference in the characteristics of mature pollen between species, with viable pollen being prolate and unicolpate with a single colpa-style aperture and a unique patterning of the pila. The structural immaturity of B. mirabilis pollen correlated with evidence from pollen growth experiments, where B. mirabilis pollen had extremely low germination rates, with those grains that did germinate being slow to do so and with slow-growing pollen tubes compared to those of fertile Borya species. Examination of the ovules of B. mirabilis showed that morphologically they were viable compared to viable Borya species. The field population of B. mirabilis was crossed, with one seed produced (the first recorded seed for th is species). Cross-pollination using the pollen of the closely related B. constricta and B. sphaerocephala with B. mirabilis ovules proved unsuccessful. Examination of the chromosome number of B. mirabilis showed that it had approximately 66 chromosomes and is probably hexaploid, relative to the diploid number of 26 in B. constricta. This may explain its low fertility. Interspecies and intraspecies relationships of the Boryaceae and Borya mirabilis were investigated using sequences of chloroplast and nuclear DNA. The closest similarities to B. mirabilis were B. constricta and B. sphaerocephala. B. mirabilis may have emerged from alloploidy of these species in the past. Because of the consistent similarities of B. mirabilis and B. constricta chloroplast sequences, it is proposed that both shared a common ancestor with a chromosome number of 2n=22. A malfunction n meiosis may have resulted in ovules with 2n=44. The high similarity of the nuclear ribosomal ITS region DNA suggests that the nuclear DNA was derived from B. sphaerocephela. B. mirabilis may be an allopolyploid, from fertilisation of a diploid ovule of B. constricta with haploid pollen of B. sphaerocephala, resulting in a reproductively isolated polyploidy of low fertility. The wild population of B. mirabilis was determined to have a small amount of genetic variation. The genetic variation in the field population w as not fully reflected in the ex-situ population. An effective means of micro-propagation of B. nitida for use in B. mirabilis has been established, providing an effective means of mass production of the species. The research has determined: a suitable explant (shoot tips) for regeneration; an effective means of reducing contamination in tissue culture (PPM); what medium is required to micro-propagate the species (LMHM); an appropriate gelling agent (Phytagel); and a practical method for inducing roots on the shoots grown in tissue culture. B. mirabilis has been established as mycorrhizal. The predominant mycorrhizal association is a nodular arbuscular mycorrhiza, present in the form of coils in root nodules over wetter months and as spores in these nodules over dryer months. A significant increase in the health of the ex-situ population of B. mirabilis was recorded after addition of soil containing fine roots of the wild population. Of the plants associated with the wild population, Callitris rhomboidea had the most morphologically similar vesicular arbuscular mycorrhizal relationship. But molecular identification was not achieved due to recalcitrance of DNA in PCR attempts. Potential translocation sites for some of the ex-situ population of B. mirabilis were examined for Phytophthora infestation. Reid's Lookout and Mackey's Peak were infected with P. cinnamomi. Vegetation at Mackey's Peak displayed characteristic infection symptoms, resulted in isolates of P. cinnamomi from baiting and would directly receive runoff from both the walking track and the existing infested B .mirabilis site. At the Reid's Lookout site, both walking track and proposed translocation site were infested with P. cinnamomi, yet did not display the associated symptoms in the vegetation. The Pine Plantation translocation site was uninfected at the level of sampling undertaken. Its vegetation did not display any characteristic infection symptoms and was not isolated when soil samples were baited. It was therefore chosen for translocation and so far the plants are healthy and actively growing. This research has provided critical knowledge to aid the recovery team in its current and future endeavours to manage this species and bring it back from the brink of extinction.

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Cegiela-Carlioz, Pascale. "Modulateurs de la MDR bactérienne dans Ligusticum porteri (Apiaceae) et Mirabilis jalapa (Nyctaginaceae)." Université Joseph Fourier (Grenoble), 2004. http://www.theses.fr/2004GRE18002.

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L'utilisation massive des antibiotiques a contribué à l'apparition de phénomènes importants de multi-résistance des bactéries constituant une menace pour la santé publique. Plusieurs mécanismes sont mis en cause mais le principal est l'expulsion active des drogues. Les transporteurs "multidrug" peuvent être divisés en deux classes majoritaires : les secondaires qui utilisent un gradient électrochimique transmembranaire de protons ou des ions Na+, comme pour la protéine TetK ou la NorA de Staphylococcus aureus (MRSA) et ceux du type ABC (ATP-Binding Cassette) utilisant l'énergie libre de l'hydrolyse de l'ATP, comme les protéines YvcC et LmrA de Escherichia Coli C41 (DE3). Une étude chimique et biologique a été réalisée sur Ligusticum porteri et Mirabilis jalapa principalement à la suite d'un criblage systématique in vitro d'extraits bruts d'Apiaceae, de Nyctaginaceae, de Scrophulariaceae, de Solanaceae afin de découvrir des composés chefs de file montrant une activité modulatrice
The important use of antibiotics is becoming a cause of the emergence of multidrug-resistant (MDR) organisms which is threat to public health. More mechanisms are involving but the major one is the multidrug efflux system. The pump of active efflux can be divided into two families: the membrane protein that extrudes drugs by using proton-motive force (a H+ anti-drug antiporter) or Na+ ions, like TetK or NorA proteins in Staphylococcus aureus (MRSA) and the ABC transporters (ATP-Binding Cassette) with energy derived from the hydrolysis of ATP, like YvcC and LmrA proteins in Escherichia Coli C41 (DE3). The phytochemistrical and biological studies realized on Ligusticum porteri and Mirabilis jalapa mainly, after a screening in vitro of crude extracts in several plants of the family Apiaceae, Nyctaginaceae, Scrophulariaceae and Solanaceae in order to find a modulator activity of leader anti-oxydant, huile essentielle, phtalides, terpénoi͏̈des, polyphénols

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Carson, L. "Novel anti-virulence and anti-infective strategies targeting the opportunistic bacterial pathogen, Proteus mirabilis." Thesis, Queen's University Belfast, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.546022.

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Stukes, James Bernard. "Evidence for the association of NR1 plasmid DNA with inner membrane of proteus mirabilis." DigitalCommons@Robert W. Woodruff Library, Atlanta University Center, 1986. http://digitalcommons.auctr.edu/dissertations/1539.

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The examination of exponent i ally grown Proteus mirabilis, in the absence and presence of chloramphenicol revealed NR1 plasmid DNA-membrane complexes when isolated on 10-30% neutral sucrose (CLOS) gradients. Subsequent analysis of CLOS generated pl asmid DNA-membrane fract ions on 30- 50% isopycnic step neutral slJcrose gradients indicated preferential association of the plasmid DNA with the inner cytoplasmic membrane. In addition, plasmid DNA-membrane complexes isolated by the Clewell-Helinski "cleared lysate" procedure indicated preferential association with the inner cytoplasmic membrane, as well. Agarose gel analysis of covalently closed circular (CCC) NR1, isolated from exponentially grown cultures of P. mirabilis in the presence of chloramphenicol revealed that the plasmid molecules maintained their composite structure of 60 Mdaltons, and did not undergo transitioning. Further, EcoR! restriction digest of these molecules confirmed the existence of NR1 plasmid DNA.

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Zunino, Pablo. "The role of fimbriae as virulence factors in urinary tract infections by Proteus mirabilis." Thesis, University of Cambridge, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.624240.

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Furness, Richard Bradshaw. "The flagellar master operon flhDC : a fulcrum controlling swarm cell differentiation of Proteus mirabilis." Thesis, University of Cambridge, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.624401.

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Snelgrove, Paul V. R. "Pollution detection models and habitat preference of the cryptofauna associated with the coral Madracis Mirabilis." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66126.

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Neuwirth, Catherine. "Phénotypes inhabituels de résistance aux bêta-lactamines chez enterobacter aerogènes, klebsiella pneumoniae et proteus mirabilis." Dijon, 1996. http://www.theses.fr/1996DIJOMU01.

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bret, Laurent. "Evolution de la resistance enzymatique aux beta-lactamines chez proteus mirabilis et escherichia coli (doctorat : microbiologie)." Clermont-Ferrand 1, 1999. http://www.theses.fr/1999CLF1MM09.

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Marques, Cátia, Marques Cátia Saraiva, and Cátia Filipa Saraiva Marques. "Uropathogenic Proteus mirabilis and Klebsiella pneumoniae in companion animals : molecular epidemiology, antimicrobial resistance and zoonotic potential." Doctoral thesis, Universidade de Lisboa, Faculdade de Medicina Veterinária, 2019. http://hdl.handle.net/10400.5/18084.

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Tese de Doutoramento em Ciências Veterinárias na Especialidade de Clínica
Urinary tract infections (UTI) are frequently diagnosed in companion animals and the increase in antimicrobial resistance leads to therapeutic limitations and public health concerns. The study of the geographic distribution of antimicrobial resistance in bacteria (n= 22 256) causing UTI in companion animals from 14 European countries showed that, in 2012-2013, the frequency of Escherichia coli and Proteus mirabilis antimicrobial resistance in Southern countries (Portugal, Spain, Italy, Greece) was significantly higher than in Northern countries (Denmark, Sweden). In a retrospective study conducted in Portugal (Lisbon), the antimicrobial resistance of clinical Enterobacteriaceae from companion animals with UTI increased significantly over 16 years (1999-2014; P < 0.001). Bacteria from companion animals with UTI harboured important antimicrobial resistance mechanisms and belonged to high-risk clonal lineages, namely third-generation cephalosporin (3GC)-resistant E. coli O25b:H4-B2-ST131, CC23 and ST648, methicilin-resistant Staphylococcus aureus CC5, methicilin-resistant Staphylococcus epidermidis CC5, high-level gentamicin-resistant Enterococcus faecalis CC6 and ampicillin-resistant Enterococcus faecium CC17. The blaCTX-M-15 gene was disseminated among 3GC-resistant K. pneumoniae from companion animals and humans with UTI. Most K. pneumoniae from companion animals where 3GC, multidrug-resistant (MDR) and belonged to the high-risk clonal lineage ST15. K. pneumoniae high-risk clonal lineages ST11, ST37 and ST147 were also detected in companion animals. 3GC-resistance in P. mirabilis from companion animals with UTI was associated with the presence of blaCMY-2, which increased significantly over time. A high number of PFGE clusters (43.6%, n = 17/39) included P. mirabilis strains from companion animals and humans. Gut colonisation by K. pneumoniae and P. mirabilis was detected in healthy dogs and humans; however, none of the strains was MDR. K. pneumoniae faecal strains from dogs belonged to ST17, ST188, ST252, ST281, ST423, ST1093, ST1241, ST3398 and ST3399. Remarkably, two colonised dogs were found to shared PFGE undistinguishable K. pneumoniae strains with one co-living human. P. mirabilis gut colonisation was significantly higher in dogs (P = 0.0329). One human/dog and one dog/dog pair shared PFGE undistinguishable P. mirabilis strains. The antimicrobial resistance frequencies reported in these studies support the need to implement antimicrobial stewardship programmes in veterinary medicine. The detection of MDR high-risk clonal lineages causing UTI in companion animals and the similarities detected in K. pneumoniae and P. mirabilis from companion animals and humans raises public health concerns and highlights the need for a One Health approach.
RESUMO - Proteus mirabilis e Klebsiella pneumoniae uropatogénicos em animais de companhia : epidemiologia molecular, resistência aos antimicrobianos e potencial zoonótico - As infeções bacterianas do trato urinário (ITU) são frequentemente diagnosticadas em animais de companhia e no homem. O aumento da resistência e multirresistência aos antimicrobianos é um reconhecido problema na sociedade moderna que resulta na diminuição de opções terapêuticas. Com o crescente contacto entre os animais de companhia e o homem, a disseminação de bactérias resistentes a antimicrobianos criticamente importantes levanta também grandes preocupações de saúde pública. Seguindo o modelo utilizado pelo European Centre for Disease Prevention and Control (ECDC) nos relatórios de resistência aos antimicrobianos de bactérias invasivas de origem humana, o primeiro estudo apresentado nesta tese pretendeu avaliar a etiologia e a distribuição geográfica da resistência aos antimicrobianos em bactérias (n= 22 256) isoladas de animais de companhia com ITU em 14 países Europeus. Este estudo mostrou que, em 2012-2013, a frequência de resistência aos antimicrobianos em Escherichia coli e Proteus mirabilis era significativamente superior nos países estudados do Sul da Europa (Portugal, Espanha, Itália e Grécia) quando comparada com os países estudados do Norte da Europa (Dinamarca e Suécia). O mesmo aconteceu quanto a E. coli e P. mirabilis multirresistente (MDR). A elevada resistência aos antimicrobianos detetada em cães e gatos com ITU em Portugal (Lisboa) motivou a realização de um segundo estudo, retrospetivo, com o objetivo de avaliar a evolução temporal da resistência aos antimicrobianos, nesta região, ao longo de um período de 16 anos (1999-2014). Este estudo confirmou a ocorrência de um aumento significativo de resistência ao longo do tempo quanto à amoxicilina/clavulanato, cefalosporinas de terceira geração (C3G), trimetoprim/sulfametoxazol, fluoroquinolonas, gentamicina e tetraciclina (P < 0,001) em Enterobacteriaceae de animais de companhia com ITU. Adicionalmente, foi detetado um aumento significativo no isolamento de Enterobacteriaceae MDR (P < 0,0001). ...
info:eu-repo/semantics/publishedVersion

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Kritzer, Van Zant Miriam. "ANALYSIS AND DEVELOPMENT OF MIRABILIS EXPANSA (RUIZ AND PAV.) STANDL.; FOR POTENTIAL AS A NEW ROOT CROP OUTSIDE THE ANDES." OpenSIUC, 2016. https://opensiuc.lib.siu.edu/dissertations/1226.

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Six topics are presented, relevant to agricultural research on two horticultural varieties of Mirabilis expansa (Ruiz and Pav.) Standl. Chapter 1, “Review of the economic and ethno-botany of the genera of the family Nyctaginaceae," includes a summary of literature on the topics included in the title, and an original taxonomic update of plant names used correctly and incorrectly as synonyms for Mirabilis jalapa, the type name for the plant family Nyctaginaceae. M. jalapa has been substituted for medicinal jalap from Mexico. Names in the Convolvulaceae for medicinal Jalap are also updated here, as they show the origin of many names which have been incorrectly used as synonyms in the Mirabilis literature. Chapter 2, “History of Mirabilis expansa (Ruiz and Pav.) Standl.; Growth and use in the Andes,” is also a literature review, incorporating information from several documents and papers which have only recently become readily available internationally via the Internet. These documents were translated into English for this chapter. Research in Chapter 3, “Field trials of Mirabilis expansa (Ruiz and Pav.) Standl. grown in North America; Growth, yield and quality traits,” showed that M. expansa horticultural varieties 'L' and 'T' are tolerant to the intense weather conditions of southern Illinois, when grown on constructed sand plots. In Chapter 4, “Amino Acid profiles for two horticultural varieties of Mirabilis expansa (Ruiz and Pav.) Standl.: A rare indigenous Andean crop grown in southern Illinois,” M. expansa was examined for its amino acid values and those values considered in terms of differnces between the two varieties and above and below ground structures. In addition, soil amendments peat and steer manure, considered alone and together, as well as structure and variety, were examined for their effect on production of amino acids in ANOVAs and Tukey-adjusted LS-Means run in SAS 9.3. In Chapter 5, “Nutrients, Comparison of Amino Acid Profiles, and Cytotoxicity Testing for Mirabilis expansa (Ruiz and Pav.) Standl.,” the amino acid profiles for M. expansa from the previous chapter are compared to profiles for other crops, eggs and milk. M. expansa is shown relatively to contain extremely high amounts of total protein. In addition published values for other nutrients for M. expansa taken from translated material are combined into two tables. Also, a cytotoxicity assay carried out in collaboration with researchers at Ohio State University was used to see if the southern Illinois M. expansa material was active against highly sensitive HT-29 colon cancer cells. Negative results from that assay serves as preliminary data for a lack of toxicity due to micro-molecules in the crop. Chapter 6, “Inexpensive nitrogen chambers for conservation of herbarium specimens,” was an outgrowth of the need to find a chemically benign manner for storing herbarium specimens of Mirabilis, used in research which led to the work described in the previous chapters. The results show that valved oxygen barrier bags, designed for clothing storage, with a small number of oxygen absorbers, can retain conditions for sufficient periods to treat specimens for pests. This allows the bags to be used as inexpensive nitrogen chambers, to treat herbarium specimens in place of expensive nitrogen systems or freezers, and without the toxic chemicals historically used in herbaria for the same purpose.

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Lahaye, Élodie. "Rôle structurant des exopolysaccharides dans un biofilm bactérien." Lorient, 2006. http://www.theses.fr/2006LORIS071.

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Les biofilms bactériens colonisent des milieux très divers, terrestres ou maritimes et ont des impacts très importants dans les bio-transformations naturelles ou industrielles (bio-procédés), sur la santé et sur les installations industrielles (colonisation de conduites, corrosion…). Que leurs effets soient positifs ou négatifs, il est essentiel de comprendre leur dynamique de développement qui repose sur le principe de l’émergence, lui-même basé sur des interactions multiples entre un grand nombre d’individus : un biofilm se caractérise par un comportement de population et non par une somme de comportements individuels. Le biofilm de Proteus mirabilis, bactérie pathogène des voies urinaires chez l’Homme, présente une structuration spatio-temporelle unique. La stratégie de colonisation de cette bactérie repose sur l’alternance de phases de consolidation et de migration. Ces deux phases sont directement liées à l’alternance de deux phénotypes bactérien, migrant et végétatif, aboutissant à la formation de terrasses concentriques. Durant ces phases de migration ou swarming, la bactérie présente une grande motilité cellulaire de l’ordre de 30µm/sec, ce facteur constitue également une caractéristique de P. Mirabilis. Dans la plupart des biofilms bactériens, la dynamique de développement repose sur des médiateurs chimiques tels que des homosérines lactones ou des furanones. Dans le biofilm de P. Mirabilis de tels agents de communications intercellulaires ne sont pas retrouvés. Notre postulat est que des grandeurs physiques comme la viscosité, l’hydratation ou l’épaisseur du biofilm pourraient évoluer de manière périodique engendrant ainsi la synchronicité observée. Nous avons analysé la matrice extracellulaire du biofilm qui s’est révélée plus complexe que prévu puisque outre deux types d’exopolysaccharides (EPS) de poids moléculaires très différents, ont été identifiés des glycolipides phénoliques (PGL) et des concentrations significatives de glycine bétaïne. Au-delà des aspects structuraux, des propriétés d’auto-assemblage de EPS et des PGL ont été démontrées par différentes techniques microscopiques. Des mesures d’hydratation, de rhéologie et de calorimétrie (DSC) menés sur les EPS et le biofilm intact indiquent que ces propriétés semi-cristallines sont étroitement liées à l’activité de l’eau. Un bilan semi-quantitatif des transferts d’eau aux interfaces gélose / biofilm / atmosphère au cours d’une phase de migration a été établi en prenant en compte les pertes par évaporation, le coefficient de diffusion de l’eau dans le milieu gélosé et le gradient d’eau à l’interface gélose / biofilm. Il en ressort que l’arrêt périodique de la migration serait lié à la dilution progressive de la matrice extracellulaire à la périphérie du biofilm. Cet accroissement du taux d’hydratation déstabiliserait les assemblages supra-moléculaires faisant perdre ainsi à la matrice les propriétés visco-élastiques indispensables à la motilité cellulaire. L’entité multi-cellulaire, le biofilm, programmerait donc l’arrêt de l’expansion de la colonie via la biosynthèse d’exoproduits dont le comportement, au delà d’un seuil d’hydratation critique ne permettrait plus la migration. La cohésion du système multicellulaire, a priori incompatible avec l’expansion, serait donc ainsi maîtrisée. Plus globalement, le développement d’un biofilm, retraçant le passage du comportement individuel à celui d’une population, transition du simple au complexe, doit nous aider à mieux comprendre l’origine de propriétés émergentes des systèmes biologiques qui nécessairement dérivent de propriétés globales plutôt que locales
Bacterial biofilms are multicellular systems able to colonize as various environments as terrestrial or marine biotopes. They are also of prime interest for most biotransformations and bioengineering processes with consequences for health and industry. Whereas their effects are considered positive or negative, it is of importance to get a deeper insight of their dynamics and emergent properties. Such systems imply multiple interactions between numerous individuals which result in a population behavior which cannot be reduced to the sum of individual behaviors. Proteus mirabilis is a bacterium which colonizes the human urinary tract by forming biofilms. On a Petri dish, the colony grows by forming a particular “bull-eye” pattern which results from alternative swarming and consolidation phases. This periodicity relies in turn on P. Mirabilis dimorphism. During a swarming phase, P. Mirabilis exhibits a fast motility through bioconvection motions (30 µm/sec) which allows the colony radius to expanse at a 60 µm/min rate. Usually, biofilm dynamics is ruled by chemical triggers like homoserine lactones or furanones. Surprisingly, P. Mirabilis biofilms lack such chemical signals. It is therefore not understood why the swarming phase stops repeatedly. The present work aims at addressing the role of the extra cellular matrix in the periodicity and synchronicity observed in a P. Mirabilis biofilm. This matrix revealed more complex as expected since two exopolysaccharides (EPS) of distinct molecular weights were observed as well as phenolic glycolipids (PGL) and significant amounts of glycine betaine, a potent osmoprotectant. Besides, infrared spectroscopy, differential scanning calorimetry and various microscopic techniques have revealed that both EPS and PGL were subject to self-organization to form supra-molecular assemblies like spherolithes. Such structures, characteristic of semi crystalline media, strongly suggest that, depending on water activity, the mechanical properties of the extra cellular matrix may vary. This was confirmed by rheological measurements which have shown that purified EPS as well as intact biofilms exhibit high viscous and elasticity modules. A semi quantitative balance of water transfers at the gelose → biofilm and biofilm → atmosphere interfaces during active swarming strongly suggests that swarmers at the colony’s periphery are subjected to dilution. It is therefore proposed that, upon hydration, the exoproducts lose their semi crystalline properties inducing thereby the decrease of the mechanical properties of the extracellular matrix. Accordingly, the swarmers will enter the dedifferenciation process, stopping de facto the colony expansion. Hence the multicellular entity is able to maintain strict control over the expansion process which is, a priori, incompatible with cohesion. By tuning the relative amounts of its exoproducts, the multicellular entity plans the limit of expansion. More generally, by featuring the transition from the individual bacterium to the population behavior, the biofilm dynamics well exemplifies the simple to complex transition which characterizes most of biological systems. For a Proteus colony, as for many other integrated systems, emergent properties arise from global, rather than local, properties

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Kumbet, Yesim. "Investigation Of Antioxidant Activities Of Fruit Juices And Herbal Teas And Their Antimicrobial Effects On Proteus Mirabilis." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612442/index.pdf.

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Herbal teas and fruit juices used in our regular diet may have importance in the protective treatment of some infectious diseases. In this study, selected dietary beverages were investigated for their antioxidant capacities and antimicrobial activities against Proteus mirabilis, a well known bacteria in urinary tract infections. Herbal teas
sage (Salvia fruticosa Mill), anise (Pimpinella anisum L.), rosehip (Rosa canina L.), camomile (Anthemis arvensis L.) and fruit juices
grape (Vitis vinifera L.), orange (Citrus sinensis L.), peach (Prunus persica L.), and pomegranate (Punica granatum L.) were chosen as samples of regular diets. Selected fruit juices and aqueous infusion tea extracts, lyophilised to dryness, were used throughout this study. Antioxidant capacities of the extracts were carried out by using 2,2&rsquo
-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging (ABTS) and 2,2-diphenyl-1-picrylhydrazyl radical scavenging (DPPH) methods along with the determination of total phenolic compounds in the extracts. Antimicrobial activities of extracts were determined by disc diffusion test, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) methods. Among the herbal teas, sage infusion extract has displayed the highest radical scavenging capacity with ABTS EC50 value of 5.152 mg/mL, DPPH EC50 value of 0.072 mg/mL and with its high phenolic content of 0.411 mg/mg gallic acid equivalence. Among the fruit juices pomegranate has revealed significantly high DPPH EC50 and TEAC values 0.924 mg/mL and 0.552 mmol/g, respectively. Peach juice has been found with the highest total phenolic amount of 0.067 mg/mg gallic acid equivalent. Antimicrobial activities of herbal teas were correlating with antioxidant capacity studies, whereas sage infusion tea extract exhibited 3 mg/mL of minimum inhibitory concentration (MIC) and 6 mg/mL of minimum bactericidal concentration (MBC). Rosehip was also found as an effective antimicrobial agent with a minimum inhibitory concentration value of 3 mg/mL. In the meantime, there was no significant difference in the zone inhibition of herbal tea infusion extracts. In case of fruit juices grape and pomegranate may be effective antimicrobials in P. mirabilis infections with 0.75 mg/mL MIC and 6 mg/mL MBC, respectively at the same time both juices revealed significantly high inhibition zones with 11 mm.

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Ho, Yat-man Alex. "Detection and characterization of extended-spectrum Beta-Lactamases among blood Isolates of Proteus mirabilis in Hong Kong." Click to view the E-thesis via HKUTO, 2004. http://sunzi.lib.hku.hk/hkuto/record/B31971805.

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47

Branton, Margaret A. "Coral reef monitoring, heat shock proteins as biomarkers of thermal stress in the scleractinian coral Madracis mirabilis." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/mq24806.pdf.

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MacLeod, Sarah M. "Study of the factors that modulate the rate of crystalline Proteus mirabilis biofilm development on urinary catheters." Thesis, Cardiff University, 2006. http://orca.cf.ac.uk/56157/.

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Around 50% of patients enduring long-term catheterisation experience encrustation and blockage of their catheters. This problem stems from infection by urease producing bacterial species, in particular Proteus mirabilis. The urease enzyme hydrolyses urea to carbon dioxide and ammonia which elevates the urinary pH. Under these alkaline conditions crystals of calcium and magnesium phosphates form and the crystalline bacterial biofilm that develops on the catheter can eventually block the flow of urine through its lumen. Catheter blockage in this way can induce complications that put the health of the patient at serious risk. Currently there are no effective methods for controlling this process and little is known about the bacterial or host factors that might modulate the rate of catheter encrustation. The extent to which catheter biofilms contain potentially dangerous levels of endotoxin is also unknown. In view of the lack of information relating to these issues the objectives of this study were to: (a) gain an insight into the complexity of the urinary flora of patients undergoing long-term catheterisation (b) examine the bacterial composition of catheter biofilms for evidence of antagonisms between Pr. mirabilis and other species (c) test the effects of other uropathogens on the ability of Pr. mirabilis to produce catheter encrustations in laboratory models of the catheterised bladder (d) examine the hypothesis that coaggregation between Pr. mirabilis and other species is involved in the formation of crystalline catheter biofilms and (e) determine whether endotoxin can be found in catheter biofilms from patients undergoing long-term catheterisation. Over a six-week period urine samples were analysed from five patients undergoing long-term catheterisation. The urinary flora was both polymicrobial and dynamic, commonly containing at least four bacterial species. The pH of the urine varied from week to week. The presence of Pr. mirabilis was always associated with alkaline urine (mean pH 8.66). The presence of other urease producing species such as Pseudomonas aeruginosa and Morganella morganii were not associated with highly alkaline urine. In the cases of the four patients who did not suffer from catheter blockages in the study period, the nucleation pH (pHn) of their urine at week six was above the pH of their voided urine (pHv). The only patient in which the pHn was below the pHv had a stable Pr. mirabilis infection and had two catheters block during the study period. A significant negative correlation was found between the urinary concentrations of calcium and magnesium and the nucleation pH value. Strategies to decrease the concentrations of these divalent cations will act to increase the nucleation pH and reduce the rate of crystal accumulation and mineralised bacterial biofilm development. To control catheter encrustation it will be essential to prevent the ability of Pr. mirabilis to elevate the pH of the urine above its nucleation pH. Analysis of the data on 106 catheter biofilm communities from long-term hospital and community-dwelling catheterised individuals revealed that the overall incidence of Pr. mirabilis was 30.19%. Particularly when species such as Klebsiella pneumoniae were recovered from catheters, the percentage incidence of Pr. mirabilis was above this figure. In contrast, when species such as Escherichia coli, Morg. morganii or Enterobacter cloacae were present on a catheter, Pr. mirabilis was rarely or never found. An experimental approach, using laboratory models of the catheterised bladder, was used to investigate the interactions of Pr. mirabilis with the test organisms Et. cloacae, Morg. morganii, Kl. pneumoniae, E. coli, and Ps. aeruginosa in more detail. Experiments in laboratory models showed that super-infection of Pr. mirabilis after 24 h growth of one of each of the test species had little or no effect on the ability of Pr. mirabilis to encrust and block catheters. However, growth of Et. cloacae, Morg. morganii, Kl. pneumoniae, or E. coli for 72 h prior to Pr. mirabilis super-infection significantly delayed catheter blockage. When Pr. mirabilis was inoculated into models 72 h after Et. cloacae for example, the mean time to blockage was extended from 28.74 h to 60.73 h (P < 0.01). In all cases however, Pr. mirabilis was eventually able to generate alkaline urine, induce crystal formation, and block the catheters. Reconstituting a four-member bacterial community from this patient significantly slowed the rise in urinary pH and postponed blockage compared to models infected with the Pr. mirabilis alone. Biofilms on sections of catheters received from patients were found to contain endotoxin levels ranging from 282.8 to 917.2 ng/4 cm length of catheter. The results from this study suggest that antagonistic interactions between Pr. mirabilis and other urinary tract organisms do exist. (Abstract shortened by UMI.)

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Ho, Yat-man Alex, and 何逸敏. "Detection and characterization of extended-spectrum Beta-Lactamases among blood Isolates of Proteus mirabilis in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B31971805.

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Edwards, Daniel C. B. "The biology of the British sea pens Virgularia mirabilis (Muller), Pennatula phosphorea Linnaeus and Funiculina quadrangularis (Pallas)." Thesis, Heriot-Watt University, 2007. http://hdl.handle.net/10399/2010.

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Dissertations / Theses on the topic 'Mirabilis'

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