Dissertations / Theses on the topic 'Mycobacterium smegmati'
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Vorwieger, Stefan [Verfasser], and Dirk [Akademischer Betreuer] Wagner. "Efflux-Inhibition bei Mycobacterium smegmatis und Mycobacterium avium." Freiburg : Universität, 2012. http://d-nb.info/1123467102/34.
Full textMpongoshe, Vuyiseka. "Gene expression changes in macrophages infected with pathogenic M. tuberculosis and non-pathogenic M. smegmatis and M. bovis BCG." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86729.
Full textENGLISH ABSTRACT: The current anti-TB drugs have had success in decreasing the number of deaths caused by TB, however, this success is limited by the emergence of drug resistant TB strains. Therefore, a novel TB therapy that limits the development of resistance has become necessary in an attempt to effectively control TB. The anti-TB drugs directly target mycobacterial enzymes, and potentiate the development of this resistance, and have therefore provided the rationale for this study. The aim was therefore to identify host macrophage genes that affect M. tb intracellular survival. The proposed alternative anti-TB therapy potentially involves the application of RNA interference (RNAi) and RNA activation (RNAa) biological processes that will target host genes, thereby inducing an indirect bactericidal effect. We hypothesized that macrophage genes that are differentially expressed by pathogenic and non-pathogenic mycobacterial species may be important in the regulation of M. tb intracellular survival. The lipid-rich mycobacterial cell wall is implicated in the excessive clumping of the mycobacterial cells in liquid culture. In order to minimize this, Tween 80 detergent was supplemented (mycobacteriaT). However, due to substantial evidence emphasising the detrimental effects of Tween 80 on the mycobacterial cell wall, mycobacteria were also cultured without Tween 80 (mycobacteriaNT), in order to investigate if the perturbed mycobacterial cell wall induced by Tween 80 affects the transcriptional response of macrophages. We endeavoured to develop a new method to culture mycobacteria without Tween 80 that will still generate single cells. We further hypothesized that the macrophage gene expression profile induced by mycobateriaNT differs from the response induced by mycobacteriaT. Differentiated THP-1 (dTHP-1) cells were infected with pathogenic and non-pathogenic mycobacteria (for 3 h, 24 h and 48 h with M. tb and M. bovis BCG, and 3 h and 8 h with M. smegmatis) cultured in the presence or absence of Tween 80. The expression of 12 macrophage genes, selected based on their involvement in the phagocytic pathway and autophagy, as well as their general involvement in the immune response, was determined by qRT-PCR and further analysed on the REST programme. The expression of each target gene was normalised relative to the expression of the reference gene (Beta actin). We observed that out of the 12 genes, TLR7 and VAMP7 were consistently downregulated in dTHP-1 cells infected with M. tbNT and upregulated in dTHP-1 cells infected with M. smegmatisNT. Their response to M. bovis BCG was inconsistent and not significantly different, and therefore could not be interpreted. Furthermore, CCL1 was upregulated by all the mycobacterial species. However, its expression was more pronounced in response to mycobacteriaNT, when compared to mycobacteriaT. Differential gene expression of TLR7 and VAMP7 in response to pathogenic and non-pathogenic mycobacteriaNT suggests that these 2 genes may be potential targets for RNAa-based anti-TB therapy, even though we could not conclude whether their response was specific to macrophages. In addition, the observed difference in the expression of CCL1 induced by mycobacteriaNT, compared to mycobacteriaT suggests that the perturbation caused by Tween 80 on the mycobacterial cell wall most likely affected the response of macrophages to infection with mycobacteria. Furthermore, this study has demonstrated a feasible method by filtration to generate single cells from mycobacteriaNT, which should be considered for future mycobacterial infection studies.
AFRIKAANSE OPSOMMING: Die huidige anti-tuberkulose middels se sukses lê daarin dat dit die aantal sterftes verminder maar hierdie sukses word weer beperk met die ontstaan van middel-weerstandige M.tb stamme. Daarom is nuwe middels nodig wat die ontwikkeling van middel-weerstandigheid beperk in ʼn poging om effektiewe TB behandeling te bewerkstellig. Anti-tuberkulose middels teiken hoofsaaklik mycobakteriële ensiemsisteme en ontlok sodoende weerstandigheid in M.tb stamme en dit vorm die rasionale vir hierdie studie. Die doel was om gasheer makrofaag gene te identifiseer wat M.tb oorlewing intrasellulêr bewerkstellig. Die voorgestelde alternatiewe anti-TB behandeling sal dan behels die toepassing van RNA intervensie (RNAi) en RNA aktivering (RNAa) tegnologie wat gasheer selgene teiken (inaktiveer) en sodoende ʼn bakterisidiese respons induseer. Die kanse is skraal dat mycobakterieë weerstandigheid sal kan ontwikkel onder hierdie omstandighede. Ons hipotetiseer dus dat makrofaag gene wat differensieel uitgedruk word deur patogeniese en nie-patologiese mycobakteriële spesies belangrik mag wees vir die oorlewing van M.tb intrasellulêr. Die lipiedryke selwand van mycobakterieë word geïmpliseer in die oormatige sameklomping van die bakterieë in vloeistofkulture. Om hierdie effek te minimaliseer word Tween 80 normaalweg tot die medium gevoeg (mycobakterieëT). Maar weens genoegsame bewyse dat Tween-80 die selwand van bakterieë nadelig beïnvloed, is mycobakterieë ook in die afwesigheid van Tween 80 gekultureer (mycobakterieëNT) om te bepaal of die nadelige effek van Tween 80 op die selwand die transkripsionele respons in makrofage beïnvloed post-infeksie. Dit was daarom ook ons doelstelling om ʼn nuwe tegniek te ontwikkel om mycobakterieë te kultureer in die afwesigheid van Tween 80 wat ook enkelselle sal genereer vir beter gekontroleerde makrofaag infeksie. Ons hipotetiseer ook verder dat makrofaag geenuitdrukking-profiele verskil afhangende of infeksie gedoen is met mycobakterieë wat in die afwesigheid of teenwoordigheid van Tween 80 gekultureer is. Gedifferensieerde THP-1 (dTHP-1) was geïnfekteer met patogeniese en nie-patogeniese mycobakterieë (vir 3 h, 24 h en 48 h met M.tb en M.bovis BCG, en 3 h en 8 h met M.smegmatis) gekultureer in die teenwoordigheid en afwesigheid van Tween 80. Die uitdrukking van 12 makrofaag gene, geselekteer op grond van hul betrokkenheid in die fagositose meganisme en in outofagie asook hul betrokkenheid in die immuunrespons, is gekwantifiseer met qRT-PCR en daaropvolgens geanaliseer met die REST-program. Die uitdrukking van elke geen is genormaliseer relatief tot die uitdrukking van die verwysingsgeen (Beta actin). Daar is bevind dat van die 12 gene, TLR7 en VAMP7 deurlopend afgereguleer was in dTHP-1 selle geïnfekteer met M.tbNT en opgereguleer was in dTHP selle geïnfekteer met M.smegmatisNT. Selrespons met M.bovis BCG was onbeduidend en derhalwe kon geen gevolgtrekking hier gemaak word nie. Ook, CCL1 was opgereguleer met infeksie deur enige van die mycobakteriële spesies, maar CCL1 se uitdrukking was groter in respons tot mycobakterieëNT wanneer vergelyk word met respons tot mycobakterieëT. Differensiële geenuitdrukking van TLR7 en VAMP7 in respons tot patogeniese en nie-patogeniese mycobakterieëNT impliseer dat hierdie twee gene potensiële teikens kan wees vir RNAa-gebaseerde anti-TB behandeling, alhoewel ons nie kon beslis of hierdie respons spesifiek vir makrofage was nie. Ook, die verskille waargeneem in die uitdrukking van CCL1 geïnduseer deur mycobakterieëNT, vergeleke met mycobakterieëT, impliseer dat die steuring in die selwand veroorsaak deur Tween 80, heelwaarskynlik die respons van die makrofaag beïnvloed het. Hierdie studie beskryf ook ʼn filtrasiemetode om enkele mycobakteriële selle te genereer wat oorweeg moet word by toekomstige mycobakteriële infeksiestudies.
CHIARELLI, PERDOMO IGOR. "PRODUCTION OF NATURAL AROMA COMPOUNDS BY BIOCATALYSIS." Doctoral thesis, Università degli Studi di Milano, 2019. http://hdl.handle.net/2434/694810.
Full textEsters play a significant role in the food industry, they are among the most important and versatile components of natural flavours and fragrances in food, drinks and cosmetics Their preparation starting from natural substrates and using bioprocesses (e.g., fermentation or enzymatic reactions) is appealing, since the final product can be labelled and commercialized in EU and USA as natural. Therefore, new biotechnological approaches for obtaining flavours are highly demanded as long as they are efficient and sustainable. Many flavour/fragrance esters can be enzymatically obtained using lipases that catalyse esterification, transesterification or interesterification reactions. In this PhD thesis we studied two systems for production of flavours esters: 1) A straightforward biocatalytic method for the enzymatic preparation of different flavour esters starting from primary alcohols (e.g., isoamyl, n-hexyl, geranyl, cinnamyl, 2-phenethyl, and benzyl alcohols) and naturally available ethyl esters (e.g., formate, acetate, propionate, and butyrate) was developed. The biotransformations are catalysed by an acyltransferase from Mycobacterium smegmatis (MsAcT) and preceded with excellent yields (80-97%) and short reaction times (30-120 minutes), even when high substrate concentrations (up to 0.5 M) were used. This enzymatic strategy represents an efficient alternative to the application of lipases in organic solvents and a significant improvement compared to already known methods in terms of reduced use of organic solvents, paving the way to a sustainable and efficient preparation of natural flavouring agents. 2) Mycelium-bound lipase of dry mycelium of Aspergillus oryzae catalysed direct esterification of alcohols and acetic acid in organic solvent, showing high stability towards substrates and products. Water produced during the esterification did not significantly affect the equilibrium of the reaction, allowing for high conversions. These features were exploited for preparing flavour-active acetate esters (e.g., isoamyl and cinnamyl acetate) in batch and continuous systems. A continuous stirred tank membrane reactor (CST-MR) was developed securing good reactor productivity and high biocatalyst stability. Both production systems are promising, represent two different alternatives and can be further optimized and scaled up for the interests of the industry.
Mahenthiralingam, Eshwar. "The amidase promotor of Mycobacterium smegmatis." Thesis, Open University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.278899.
Full textBruell, Christian M. "Mechanism of protein synthesis in Mycobacterium smegmatis /." Zürich : ETH, 2008. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17733.
Full textTrower, Carolyn Joy 1975. "A preliminary investigation of a sialidase activity associated with M. smegmatis." Monash University, Dept. of Medicinal Chemistry, 2003. http://arrow.monash.edu.au/hdl/1959.1/7646.
Full textBerger, Sven. "Expression der Poren bildenden Hämolysine Listeriolysin und TlyA in Mycobacterium smegmatis." [S.l. : s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=964920824.
Full textFaller, Michael. "Kristallstruktur eines mycobacteriellen Porins." [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=972775730.
Full textSmeulders, Maria Jeanne. "The stationary phase survival response of Mycobacterium smegmatis." Thesis, Imperial College London, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.287866.
Full textSikder, Mahmudul Hasan. "Characterisation of the Mycobacterium smegmatis transcriptional regulator MSMEG_5424." Thesis, Royal Veterinary College (University of London), 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.618297.
Full textRao, Tara. "Analysis of the multiple chaperonins of Mycobacterium smegmatis." Thesis, University of Birmingham, 2010. http://etheses.bham.ac.uk//id/eprint/1006/.
Full textOgwang, Sam. "Intrinsic Antifolate Resistance in Mycobacterium smegmatis." Case Western Reserve University School of Graduate Studies / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=case1270147885.
Full textWhiteford, Danelle. "Stress survival in Mycobacterium tuberculosis and Mycobacterium bovis and the role of hup in Mycobacterium smegmatis." Pullman, Wash. : Washington State University, 2008. http://www.dissertations.wsu.edu/Dissertations/Fall2008/D_Whiteford_100908.pdf.
Full textLamrabet, Otmane. "Modifications génétiques de Mycobacterium tuberculosis : interactions avec les organismes hôtes." Thesis, Aix-Marseille, 2012. http://www.theses.fr/2012AIXM5027/document.
Full textMycobacteria are mycolic-acid containing, high GC% bacterial organisms which can be recovered from soil and fresh water environments where free-living protozoa also live. Co-isolation of mycobacteria and amoeba collected from such environmental sources has been reported. Several experiments further demonstrated the ability of most environmental mycobacteria to survive in the amoebal trophozoites and cysts and in some eukaryotic cells including macrophages. Genetic modification of mycobacteria in general and mycobacteria belonging to Mycobacterium tuberculosis complex in particular are complicated and no studies using genetic modification of mycobacteria (pathogenic or non-pathogenic) had been performed in our laboratory prior to our work. In our thesis work, we showed that amoebae or other phagocytic organisms can serve as sources and places for gene transfers in mycobacteria. Gene transfers may have contributed to the adaptation of mycobacteria to an intracellular lifestyle. In addition, we developed two co-culture systems: Mycobacterium smegmatis-Acanthamoeba polyphaga and Mycobacterium gilvum-A. polyphaga and we clarified the spectrum of rapid-growing mycobacteria and amoeba interactions. This model of mycobacteria-amoeba interactions was then used to test another hypothesis according to which unlike the prevailing paradigm, the addition of genes does not reduce the virulence of bacteria. For the first time in our laboratory we modified two species of the M. tuberculosis complex, M. tuberculosis H37Rv and Mycobacterium bovis BCG to observe the effect of these changes on their pathogenicity and survival
REVEL, VIRAVAU VALERIE. "Quinolones et mycobacteries : identification, caracterisation biochimique et role de l'adn gyrase de mycobacterium smegmatis dans la resistance aux quinolones." Paris 6, 1996. http://www.theses.fr/1996PA066679.
Full textde, Camargo Bertuso Paula. "Roles of regulation of mRNA cleavage in Mycobacterium smegmatis." Digital WPI, 2016. https://digitalcommons.wpi.edu/etd-theses/776.
Full textKirsten, Catriona Jane. "Nitrogen metabolism and the regulation thereof in Mycobacterium smegmatis." Thesis, Stellenbosch : University of Stellenbosch, 2011. http://hdl.handle.net/10019.1/17991.
Full textENGLISH ABSTRACT: The nitrogen metabolic pathway is essential for growth and survival of all living organisms including prokaryotes. Certain components of the pathway, such as the enzyme glutamine synthetase (GS), have been studied; however, little information is available regarding the pathway in the mycobacteria. Our in silico studies revealed that many of the components and mechanisms involved in the pathway appear to be conserved between closely related Actinomycetales. Therefore, we investigated three aspects of nitrogen metabolic control in Mycobacterium smegmatis; namely, transcriptional regulation of nitrogen metabolism-related genes, control of enzyme activity and the signalling cascade governing the nitrogen metabolic response. At the transcriptional level, it was found that nitrogen metabolism-related genes were regulated in response to ammonium availability. Two possible transcriptional regulators, AmtR and GlnR, which are the regulators responsible for control of nitrogen-related gene transcription in Streptomyces coelicolor and Corynebacterium glutamicum respectively, were identified in M. smegmatis. Through generation of amtR and glnR deletion mutants, we found that both potential regulators played a role in the control of nitrogen-related gene expression in M. smegmatis. GlnR acted as both an activator and repressor of gene transcription whilst AmtR appeared to activate gene expression which is different to the role its homolog plays in C. glutamicum. On a protein level we found that both GS and glutamate dehydrogenase (GDH) were responsible for ammonium assimilation in M. smegmatis and were regulated in response to ammonium availability. Two GDH isoforms (NAD+- and NADP+-specific) were identified in M. smegmatis and whereas only an NAD+-GDH was detected in M. tuberculosis. The M. tuberculosis GDH also played a largely anabolic role with regard to ammonium assimilation which is in contrast to the belief that ammonium can only be assimilated via GS in this pathogen. The signaling cascade was investigated through generation of a glnD deletion mutant in M. smegmatis. We were able to show that this pivotal protein (GlnD) was able to relay the cellular nitrogen status to the transcriptional machinery as well as to GS. The data presented in this study has advanced our understanding of the nitrogen metabolic pathway in the mycobacteria. Through elucidation of such pathways, our knowledge of mycobacterial physiology and thus infection and survival improves, which could ultimately lead to the discovery of novel mechanisms to aid in the eradication of the disease.
AFRIKAANSE OPSOMMING: Stikstof metabolisme is noodsaaklik vir die oorlewing en groei van alle organismes, prokariote ingesluit. Sekere sellulêre komponente, soos die ensiem glutamine sintetase (GS), is al tevore bestudeer, maar baie min verdere inligting is beskikbaar oor stikstof metabolisme in die mycobacteria. Ons in silico studies het gewys dat baie van die komponente en meganismes gekonserveerd gebly het tussen nou-verwante Actinomycetales. Dus het ons drie aspekte in die beheer van stikstof metabolisme ondersoek; naamlik, die transkriptionele regulering van stikstof metabolisme-verwante gene, die beheer van ensiem aktiwiteit en die sein-meganisme wat die reaksie op stikstof konsentrasie reageer. Op transkripsionele vlak het ons gevind dat stikstof metabolisme-verwante gene gereguleer word in reaksie op stikstof beskikbaarheid. AmtR en GlnR is twee moontlike transkripsie reguleerders wat verantwoordelik is vir transkripsionele beheer in onderskeidelik Streptomyces coelicolor en Corynebacterium glutamicum. Beide hierdie proteïene is geïdentifiseer in M. smegmatis. Deur die konstruksie van amtR en glnR mutante, het ons gevind dat beide potensiële reguleerders ‘n rol gespeel het in die beheer van stikstof-verwante transkripsie in M. smegmatis. GlnR het opgetree as beide ‘n aktiveerder en ‘n onderdrukker van transkripsie terwyl AmtR net ‘n aktiverende rol gespeel het. Die funksie van AmtR in M. smegmatis is dus verskillend van sy homoloog in C. glutamicum. Op proteïen-vlak het ons gevind dat beide GS en glutamaat dehidrogenase (GDH) verantwoordelik was vir die assimilasie van ammonium in M. smegmatis en albei was gereguleer in reaksie op ammonium beskikbaarheid. Twee vorme van GDH (NAD+- spesifieke- en NADP+-spesifieke GDH) was geïdentifiseer in M. smegmatis terwyl net ‘n NAD+- spesifieke GDH in M. tuberculosis gevind is. Die M. tuberculosis GDH het ook ‘n anaboliesie rol gespeel met betrekking tot ammonium assimilasie wat in teenstelling is met die huidige opvatting dat ammonium alleenlik deur GS ge-assimileer kan word. Die sein-meganisme is ondersoek deur ‘n glnD M. smegmatis mutant te konstrueer. Ons het bewys dat hierdie deurslaggewende proteïen (GlnD) die sellulêre stikstof status aan die transkripsionele masjinerie, en aan GS kon oordra. Die data wat in hierdie studie voorgelê word, het ons kennis van stikstof metabolisme in die mycobacteria gevorder. Sodanige metaboliese studies verbreed ons kennis van mycobacteriële fisiologie en dus M. tuberculosis infeksie en oorlewing en kan uiteindelik lei tot die ontdekking van unieke teiken meganismes om te help met die beheer van die siekte en nuwe middelontwikkeling.
Shires, Karen Lesley. "Characterisation of the cold-shock response in Mycobacterium smegmatis." Doctoral thesis, University of Cape Town, 1999. http://hdl.handle.net/11427/25670.
Full textKirykowicz, Angela Mary. "High-Throughput Determination of Mycobacterium smegmatis Protein Complex Structures." Master's thesis, University of Cape Town, 2018. http://hdl.handle.net/11427/29644.
Full textMothiba, Maborwa Tebogo. "The effects of clofazimine on mycobacterium smegmatis biofilm formation." Diss., University of Pretoria, 2013. http://hdl.handle.net/2263/31569.
Full textDissertation (MSc)--University of Pretoria, 2013.
Immunology
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Schneider, Cristopher Zandoná. "Construção e estudo de mutantes envolvidos na biossíntese de aminoácidos aromáticos e purinas em Mycobacterium tuberculosis e Mycobacterium smegmatis por troca alélica." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2007. http://hdl.handle.net/10183/30206.
Full textTuberculosis (TB), a serious infectious disease caused by Mycobacterium tuberculosis, still remains a public health problem in the world. New drugs and second generation vaccines are urgently required to control TB, but the complex biology of M. tuberculosis has hindered the development of novel therapeutic tools. Genetic manipulation of M. tuberculosis is also difficult, but currently new, more efficient gene replacement techniques have allowed detailed studies of many mycobacterial genes. In the present work, the chorismate mutase (CM) and purine nucleoside phosphorylase (PNP) genes from M. tuberculosis and Mycobacterium smegmatis were studied. CM catalyzes the rearrangement of chorismate to prephenate in the biosynthetic pathway that forms phenylalanine and tyrosine in bacteria, fungi, and plants. Two monofunctional CM genes (aroQ and *aroQ) were identified, cloned, expressed, and biochemically characterized in both mycobacteria. Those genes were also investigated by homologous recombination methods and promoter activity assays. AroQ genes seem to be essential for the growth of M. tuberculosis and M. smegmatis, while an *aroQ mutant strain could be generated in M. smegmatis. PNP promotes the interconversion and recycling of purine bases, nucleosides, and nucleotides in the purine salvage pathway. Construction of deoD (which codes for PNP) deletion mutants of M. tuberculosis and M. smegmatis using an efficient two-step gene replacement technique was not possible. Thus, it is suggested that deoD is also essential for mycobacterial growth under the conditions tested. The identification of essential genes is of great importance, both because it indicates their biological significance, and because, with pathogens like M. tuberculosis, these may also indicate attractive molecular targets for the development of new antimycobacterial drugs.
Brooke, Edward W. "Protein-ligand interactions of arylamine N-acetyltransferase from Mycobacterium smegmatis." Thesis, University of Oxford, 2003. http://ora.ox.ac.uk/objects/uuid:f13c3191-b098-4a85-84c3-90590b365d30.
Full textBurgess, Jeremy Gareth. "Helical reconstruction of Mycobacterium smegmatis Mycothiol S-conjugate amidase filaments." Master's thesis, University of Cape Town, 2017. http://hdl.handle.net/11427/24868.
Full textZhang, Tianbu. "Structural and biochemical studies of F₁-ATPase from Mycobacterium smegmatis." Thesis, University of Cambridge, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.708118.
Full textIngvarsson, Henrik. "Structural studies of Caseinolytic protease 1 from Mycobacterium tuberculosis and Methionyl-tRNA synthetase from Mycobacterium smegmatis." Doctoral thesis, Uppsala universitet, Strukturell molekylärbiologi, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-121779.
Full textVICENTE, Iêda Cristina da Silva. "Atividade bactericida de um novo derivado 1,2,4-oxadiazol-hidrazida frente ao Mycobacterium fortuitum e Mycobacterium smegmatis." Universidade Federal de Pernambuco, 2003. https://repositorio.ufpe.br/handle/123456789/1352.
Full textAs infecções causadas pelas micobactérias atípicas são freqüentes em pacientes imunocomprometidos, particularmente aqueles contaminados com o HIV. Os quimioterápicos normalmente utilizados não são suficientes, devido a crescente deficiência no tratamento da tuberculose e micobacterioses. Por esta razão, novos experimentos são necessários para obtenção de novas drogas para o tratamento desses pacientes. O objetivo desse estudo foi determinar in vitro a atividade bactericida de uma nova hidrazida, [3-(4-hidroxi-fenil)-1,2,4-oxadiazol-5-il]- acil - hidrazida e de sua associação com o p-flúor-fenilalanina, um inibidor da biossíntese do micosídio-C. Os microrganismos testados M. fortuitum e M. smegmatis foram isolados de pacientes imunocomprometidos hospitalizados. A atividade bactericida in vitro do derivado hidrazínico e p-flúor-fenilalanina e sua associação foram estudadas pelo método da curva de morte versus tempo (Time Killing Curve). Após 120 horas de exposição foram observados um decréscimo no crescimento de 1,45 ± 0,39 log10 e 2,41 ± 0,17 log10 frente o M. fortuitum e M. smegmatis, respectivamente. Com a pflúor- fenilalanina não foi observada nenhuma diminuição do crescimento. Nas associações foram observadas as diminuições do crescimento de 1,08 ± 0,59 log10 frente ao M. fortuitum e de 2,08 ± 0,25 log10 para o M. smegmatis. Não foi verificado recrescimento nas culturas. O derivado hidrazínico demonstrou atividade contra o M. fortuitum e M. smegmatis, contudo sua atividade não foi acentuada na associação com o p-flúor-fenilalanina
Almourfi, Feras. "Structural genomic studies of lipoproteins from Mycobacterium smegmatis for drug design." Thesis, University of Sheffield, 2014. http://etheses.whiterose.ac.uk/6666/.
Full textOliveira, Fábio Muniz de. "Mycobacterium smegmatis recombinante expressando a proteína CMX induz resposta imune contra Mycobacterium tuberculosis em camundongos BALB/c." Universidade Federal de Goiás, 2014. http://repositorio.bc.ufg.br/tede/handle/tede/3457.
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Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq
For hundreds years tuberculosis (TB), a contagious disease caused by Mycobacterium tuberculosis (Mtb), has been a global public health problem. Even after the development of the vaccine BCG, in 1921, tuberculosis control continues on slow pace. This comes to be as a result of the variable efficacy (from 0 to 80%) presented by the vaccine in the protection against TB in adults. Therefore, the development of a new vaccine against TB is necessary. In this study, it was evaluated a recombinant vaccine composed of Mycobacterium smegmatis expressing the CMX fusion protein (mc2- CMX), formed from three antigen epitopes of Mtb: Ag85C, MPT51 and HspX. M. smegmatis mc2 155 was transformed with pLA71-CMX by electroporation, and the presence of the CMX protein was confirmed by imuno blotting. BALB/c mice were distributed in four groups: saline, infection, BCG and mc2-CMX. The groups were immunized with their respective vaccines in two moments with an interval of fifteen days and the animal blood was collected fifteen days after the last immunization. Thirty days after the last immunization, the animals were challenged with Mtb H37Rv (intravenously) and thirty days after the challenge, the blood was collected to perform ELISA test. Seventy days after the challenge, the lungs from all mice were collected to obtain cells for flow-cytometry, histological analysis and also to determine the bacillary burden. The immunization with mc2-CMX induced higher levels of antibodies of IgG1 (1,910±0,70) and IgG2a (0,139±0,020) class anti-CMX when compared with BCG group (0,646±0,19 and 0,413±0,24; respectively, p<0,05). These results demonstrated the relevance of CMX antigen in the immunogenicity of the recombinant vaccine. Seventy days after the challenge, the amount of T CD4 cells in the lung producing Th1- type cytokines was assessed. It was observed a significant increase in the percentage of T CD4 cells positive for IFN-γ and TNF-α in the immunized mice with mc2-CMX vaccine, when compared with the group immunized with BCG. Mice challenged with Mtb presented significant higher percentage of IL-2 producer cells when compared with the non-immunized group. However, only the mice immunized with the vaccine mc2- CMX presented significant higher percentage when compared with the infection group. The immune response induced by the vaccine was effective in the control of Mtb infection, confirmed by the histological analysis and the bacillar burden determined. The groups vaccinated with mc2-CMX and BCG presented a significant reduction of the lung lesion induced by the Mtb infection, and also lung bacterial load, when compared with the infection group. Thus, the recombinant vaccine mc2-CMX presents potential characteristics to be used in the prevention of TB.
Há séculos a tuberculose (TB), doença infectocontagiosa causada por Mycobacterium tuberculosis (Mtb), vem sendo um problema de saúde pública mundial. Mesmo após o surgimento da vacina BCG em 1921, o controle da tuberculose continua a passos lentos. Isso se deve à eficácia variável de 0 a 80% apresentada pela vacina na proteção contra TB em indivíduos adultos. Deste modo, o desenvolvimento de uma nova vacina contra a TB é necessário. Neste estudo, avaliou-se uma vacina recombinante composta por Mycobacterium smegmatis expressando a proteína de fusão CMX (mc2-CMX), formada por três antígenos do Mtb: Ag85C, MPT51 e HspX. M. smegmatis mc2 155 foi transformado com pLA71-CMX por eletroporação, sendo a expressão da proteína CMX confirmada por imunoblot. Camundongos BALB/c foram distribuídos em quatro grupos: salina, infecção, BCG e mc2-CMX. Os grupos foram imunizados com suas respectivas vacinas em dois momentos com intervalos de 15 dias, e o sangue de todos os animais coletado quinze dias após a última imunização. Trinta dias após a imunização, os animais foram desafiados com Mtb H37Rv (via endovenosa) e trinta dias após o desafio, o sangue foi coletado para realização de ELISA. Setenta dias após desafio, o pulmão e o baço de todos os camundongos foi coletado para obtenção de células para realização de citometria, histopatológico e determinação da carga bacilar. A imunização com o mc2-CMX induziu níveis maiores de anticorpos da classe IgG1 (1,910±0,70) e IgG2a (0,139±0,020) anti-CMX quando comparado com o grupo BCG (0,646±0,19 e 0,413±0,24, respectivamente, p<0,05). Estes resultados demonstram a relevância do antígeno CMX na imunogenicidade da vacina recombinante. Após setenta dias do desafio, a quantidade de células T CD4 produtoras de citocinas do tipo Th1 foi analisada no pulmão. Foi observado um aumento significativo na porcentagem de células T CD4 positivas para IFN-γ e TNF-α nos camundongos imunizados com vacina mc2-CMX, quando comparado com o grupo BCG. Camundongos desafiados com Mtb apresentaram porcentagens maiores de células produtoras de IL-2, quando comparado com o grupo não desafiado. Todavia, somente os camundongos imunizados com a vacina mc2-CMX apresentaram porcentagens significativamente maiores em comparação ao grupo infecção. A resposta imune observada foi efetiva no controle da infecção por Mtb, sendo isto confirmado quando os pulmões dos camundongos foram analisados histologicamente e a carga bacilar determinada. Os grupos vacinados com as vacinas mc2-CMX e BCG apresentaram uma redução significativa da lesão pulmonar induzida pela infecção por Mtb, e também da carga bacilar no pulmão, quando comparados com o grupo infecção. Conclui-se que mc2-CMX tem um bom potencial para ser explorado como vacina contra a TB.
SHANAHAN, Erin Rose. "Molecular investigation of mycobacterium tuberculosis and the critical cell wall lipase culp6." Thesis, The University of Sydney, 2014. http://hdl.handle.net/2123/10066.
Full textO'Brien, Lyn. "An investigation of the killing of Mycobacterium tuberculosis by macrophages and the acid stress response of Mycobacterium smegmatis." Thesis, University of Leicester, 1995. http://hdl.handle.net/2381/35403.
Full textSteyn, Natassja Lise. "Investigating the localisation of the ESX-3 secretion system in Mycobacterium smegmatis." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/71959.
Full textENGLISH ABSTRACT: Mycobacterium tuberculosis is a pathogenic organism that infects a third of the world’s population and causes approximately 2 million deaths per year. Extensive research has been done on this pathogen, however our knowledge of the mechanisms of pathogenicity remain limited. The M. tuberculosis genome contains five ESAT-6 gene cluster regions, ESX-1 to 5, which encode specialized type VII secretion systems. These secretion systems are known to secrete members of the ESAT-6/CFP-10 and PE/PPE protein families, some of which contribute to the pathogenicity and phagosomal escape of the pathogen. ESX-3 has been shown to be essential for in vitro growth and survival of M. tuberculosis. The expression of ESX-3 in M. tuberculosis is regulated by IdeR and Zur, in response to intracellular iron and zinc concentrations, respectively. Interestingly, ESX-3 is not essential for the growth and survival of the saprophytic organism M. smegmatis. In this study, we aimed to identify the subcellular localisation of the individual components of the ESX-3 secretion system in the non-pathogenic, fast-growing organism M. smegmatis. The esx conserved component (ecc) genes from ESX-3 were expressed from the episomal expression vector pDMNI as fusion proteins with green fluorescent protein (GFP). MSMEG_0615 (eccA3), MSMEG_0616 (eccB3), MSMEG_0623 (eccD3) and MSMEG_0626 (eccE3) were successfully cloned into pDMNI and expression of fusion proteins was confirmed by Western blotting for MSMEG_0615-GFP, MSMEG_0616-GFP and MSMEG_0626-GFP in M. smegmatis. In the M. smegmatis ESX-3 knock-out (with MSMEG_0615 to MSMEG_0626 deleted) expression was confirmed for MSMEG_0615-GFP and MSMEG0626-GFP. Fluorescent microscopy determined that MSMEG_0615-GFP localised to a single mycobacterial pole in both strains. MSMEG_0616-GFP and MSMEG_0626-GFP were found to be membrane associated in M. smegmatis, while MSMEG_0626-GFP was found to be membrane associated in the M. smegmatis ESX-3 knock-out. The unipolar localisation of MSMEG_0615-GFP suggests that the assembled ESX-3 secretion system apparatus is situated at a single pole in M. smegmatis. Therefore, we hypothesize that MSMEG_0615 might act as a recruiter protein that is involved in the assembly of ESX-3 at the mycobacterial pole.
AFRIKAANSE OPSOMMING: Mycobacterium tuberculosis is ‘n patogene organisme wat ‘n derde van die wêreld se bevolking infekteer en eis jaarliks 2 miljoen lewens deur tuberkulose. Ten spyte van uitgebreide navorsing, is daar min kennis oor die meganismes van patogenisiteit van hierdie organisme. Die M. tuberculosis genoom bevat vyf duplikasies van die ESAT-6 geen groep gebiede, ESX-1 tot 5, wat kodeer vir gespesialiseerde Tipe VII sekresie sisteme. Hierdie sekresie sisteme is bekend vir die sekresie van lede van die ESAT-6/CFP-10 en PE/PPE proteïen families, waarvan sommige bydra tot die patogenisieit en fagosomale ontsnapping van hierdie organisme. ESX-3 is noodsaaklik vir die in vitro groei en oorlewing van M. tuberculosis. Die uitdrukking van ESX-3 in M. tuberculosis word gereguleer deur IdeR en Zur in reaksie op intrasellulêre yster en sink konsentrasies, onderskeidelik. ESX-3 word nie benodig vir die groei en oorlewing van die saprofitiese organisme M. smegmatis nie. Hierdie studie was gemik om die sub-sellulêre lokalisering van ESX-3 te identifiseer in die niepatogeniese en vinnig-groeiende organisme, M. smegmatis. Die “esx conserved component” (ecc) gene van ESX-3 is uitgedruk vanaf die episomale uitdrukkingsvektor pDMNI as gekombineerde proteïene met die groen fluoreserende proteïen (GFP). MSMEG_0615 (eccA3), MSMEG_0616 (eccB3), MSMEG_0623 (eccD3) en MSMEG_0626 (eccE3) is suksesvol gekloneer en die uitdrukking van die gekombineerde proteïene is bevestig deur Western oordrag vir MSMEG_0615-GFP, MSMEG_0616-GFP en MSMEG_0626-GFP in M. smegmatis. In die M. smegmatis ESX-3 uitklopmutant (met MSMEG_0615 tot MSMEG_0626 uitgeslaan) is uitdrukking bevestig vir MSMEG_0615-GFP en MSMEG0626-GFP. Fluoresensie mikroskopie het bepaal dat MSMEG_0615-GFP gelokaliseer is by ‘n enkele mikobakteriese pool in beide stamme. MSMEG_0616-GFP en MSMEG_0626-GFP was membraan-geassosieerd in M. smegmatis, terwyl en MSMEG_0626-GFP geassosieer het met die membraan in die M. smegmatis uitklopmutant. MSMEG_0615 het gelokaliseer by ‘n enkele pool in M. smegmatis en dit dui aan dat die saamgestelde ESX-3 sekresie sisteem apparaat slegs by ‘n enkele pool voorkom in M. smegmatis. Ons hipotiseer dat MSMEG_0615 dalk mag optree as ‘n werwer proteïen wat betrokke is by die samestelling van die ESX-3 sekresie sisteem by die mikrobakteriese pool.
Stellenbosch University
MARINHO, Victor Hugo de Souza. "O papel do colesterol na biossíntese da parede celular de Mycobacterium smegmatis." Universidade Federal do Pará, 2015. http://repositorio.ufpa.br/jspui/handle/2011/7453.
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CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Diferentes espécies de micobactérias são agentes causadores de significativas doenças em seres humanos como, por exemplo, a tuberculose. Todas as micobactérias possuem uma complexa e distinta parede celular, conferindo características físico-químicas exclusivas ao gênero Mycobacterium, protegendo-o contra o sistema imune e entrada de muitos antibióticos. Durante a infecção, o bacilo é capaz de se adaptar ao ambiente inóspito, nutrindo-se de fontes lipídicas alternativas, principalmente o colesterol, da própria célula hospedeira (macrófagos). Este perfil nutricional tem sido considerado essencial para a divisão bacilar e consecutivamente progressão da doença. Diante disso, o presente trabalho tem por objetivo avaliar em Mycobacterium smegmatis (espécie saprofítica) a modulação in vitro da biossíntese de constituintes bioativos da parede celular após o consumo de colesterol. Como resultado, verificamos por Cromatografia de Camada Delgada (CCD) que a adaptação do bacilo ao microambiente de escassez nutricional (cultivo em Meio Mínimo – MM) conseguiu manter a biossíntese e o acúmulo dos principais constituintes da parede celular, quando o cultivo ocorre na presença de alguma fonte definida de carbono e energia (glicerol e/ou colesterol). Dentre estes constituintes essenciais sem alterações, verificamos o Trealose de dimicolato (TDM) e os fosfolipídios Fosfatidilinositol (PI), Fosfatidilinositol manosídeos (PIMs), Cardiolipina (CL) e Fosfatidiletanolamina (PE). Diferentemente a esse resultado, o ácido micólico apresentou acúmulo representativo ao cultivo em meio 7H9 somente quando o MM estava igualmente suplementado com glicerol. Este resultado foi confirmado pela marcação álcool-ácido resistente com o marcador fluorescente auroamina, sugerindo alterações nas propriedades físico-químicas da parede celular. Por outro lado, o cultivo em MM favoreceu o acúmulo de Glicopeptídeolipídios (GPLs), independente da suplementação por glicerol e/ou colesterol. Esta perturbação na biossíntese da parede celular alterou o perfil hidrofóbico do bacilo, independentemente da fonte de carbono e energia, porém não alterou a resistência ou sensibilidade a antibióticos. Estes resultados mostram claramente que a biossíntese da parede celular pode sofre modulações em condições de escassez nutricional, e que a presença ou ausência de colesterol, como ocorrido durante a infecção, não altera significativamente a fisiologia do bacilo a ponto de torna-lo mais vulnerável a ação de antibióticos, sugerindo que tais modificações possam também ocorrer durante a infecção, mantendo o bacilo viável, até o desenvolvimento da doença propriamente dita.
Different Mycobacterium species are causative agents of disease in humans, for example, the tuberculosis. All mycobacteria have a complex cell wall, distinct of others bacteria, conferring specific physic-chemical characteristic to Mycobacterium genus, due to protect against immune system and waterproofing against the intake of much antibiotics. During infection, the bacillus is able to adapter to harsh environment, due to consumption of cholesterol from itself host cell (macrophages) as alternative carbon and energy source. That nutritional aspect has been considered as essential for division of bacilli and consecutive progress of tuberculosis disease. The present study has as objective to evaluate in vitro the modulation of saprophytic Mycobacterium smegmatis cell wall biosynthesis after cholesterol consumption as primordial energy and carbon source. As results, we are found by Thin Layer Chromatography (TLC) that bacillary adaptation to microenvironment with poor nutrient (minimal media – MM) maintained the biosynthesis and accumulation of essential cell wall components, when the growth occurs in presence of someone defined carbon and energy source (glycerol and/or cholesterol). Among them without changes, we analyzed Trehalose Dimicolate (TDM) and the phospholipids (phosphatidylinositol (PI), phosphatidylinositol manosides (PIMs), Cardiolipin (CL) and phosphatidylethanolamine (PE)). Differently of these results, the micolic acid showed representative accumulation, comparing with 7H9 culture, only when the MM was supplemented with glycerol. This result was confirmed by alcohol-acid staining using fluorescent auroamine dye, suggesting some changes in physic-chemistry cell wall properties. On the other hands, the MM culture induced the accumulation of glycopeptidolipids (GPLs), independently of glycerol/cholesterol supplementation. Such disturbance in cell wall biosynthesis also changed the bacillary hydrophobicity in all MM groups, but does not change the resistance and sensibility to antibiotics. Those results clearly show that cell wall biosynthesis might be modulate during nutritional shortage, and such presence or absence of cholesterol, as occurs during infection, does not significantly change the bacillary physiology to become vulnerable for antibiotics. It suggests that such modulations might also occur during infection, maintaining the bacilli available to develop the tuberculosis diseases.
Joyce, Graham. "Organisation of the Mycobacterium smegmatis chromosome and its role in cell division." Thesis, Imperial College London, 2010. http://hdl.handle.net/10044/1/6831.
Full textSafavi-Khasraghi, Mitra. "EXPRESSION AND CHARACTERIZATION OF MYCOBACTERIUM PARATUBERCULOSIS 19KDA WITH POSTTRANSLATIONAL MODIFICATION." Master's thesis, University of Central Florida, 2006. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3080.
Full textM.S.
Department of Molecular Biology and Microbiology
Burnett College of Biomedical Sciences
Molecular Biology and Microbiology
Bakala, n'goma Jean-claude. "Etude In vitro de Phospholipases mycobactériennes impliquées dans la virulence." Thesis, Aix-Marseille 2, 2010. http://www.theses.fr/2010AIX22027/document.
Full textPhospholipases, particularly phospholipases C, are important virulence factors in several pathogenic bacteria (C. perfringens, B. cereus, L. monocytogenese and P. aeruginosa). However, little is know on the involvement of thses enzymes in mycobacteria pathogenesis. Although study on M. tuberculosis phospholipases C mutants in a mouse aerosol model of infection gave rise to the contribution of these proteins in virulence process, but their exact biochemical properties, mechanism of action and physiological role remain to be elucidated. This lack of data on mycobacterial phospholipases is mainly due to the difficulty to produce and purify these enzymes in large scale.With the aim to better characterise the physiological role of mycobacterial phospholipases, the main challenge of my thesis was to develop an efficient method for expression and purification of recombinant mycobacterial phospholipases C. Since no satisfactory results have been obtained with standard expression systems (E. coli, Pichia pastoris and baculovirus / insect cells), we develop a robust expression technique for these proteins using M. smegmatis as expression system.This allowed us to produce and purify all four PLC (PLC-A, PLC-B, PLC-C and PLC-D) of M. tuberculosis and the PLC of M. abscessus in soluble and active form. For the first time, we have show, that purified proteins have cytotoxic effect on mouse macrophages but have not haemolytic activity. Using radiolabelled lipids, we have confirmed that this first direct evidence that PLC are involved in infection and virulence processes. Another aspect of my thesis work concerned the study of two other secreted proteins of M. tuberculosis belonging to the cutinase family : the Rv 1984c ant the Rv3452. Recombinant proteins obtains in E. coli were found to have distinct substrate specificities and most likely distict physiological role, despite showing 50% amino acids sequence identity. Rv1984c is a lipase and is able to hydrolyse lipids with medium chains lengthn whereas Rv3452 is type A2, phospholipase and i able to induce macrophage lysis
Czuchra, Alexander. "The DNA Translocase of Mycobacteria Is an Essential Protein Required for Growth and Division." eScholarship@UMMS, 2021. https://escholarship.umassmed.edu/gsbs_diss/1151.
Full textAbbehusen, Melissa Moura Costa. "Estudo da imunogenicidade de vacinas de Mycobacterium smegmatis recombinante, expressando o gene que codifica aproteína ácida ribossomal de Leishmania infantum (LiP0), contra a infecção por Leishmania chagasi em hamster." reponame:Repositório Institucional da FIOCRUZ, 2011. https://www.arca.fiocruz.br/handle/icict/4254.
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Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, Bahia, Brasil
A Proteína ácida ribossomal de Leishmania infantum (L. infantum) - LiP0 é um componente estrutural da subunidade maior do ribossomo e já foi descrita como um antígeno imunodominante, que participa na síntese de outras proteínas e é capaz de induzir resposta imune humoral específica em soro de pacientes e cães infectados com Leishmania chagasi (L. chagasi). Mycobacterium smegmatis (M. smegmatis), é uma micobactéria oportunista, que apresenta crescimento rápido e uma poderosa capacidade adjuvante, já sendo utilizado como vetor de expressão para diversos antígenos. Neste trabalho avaliamos a capacidade imunoprotetora do Mycobacterium smegmatis recombinante (rM.smegmatis) expressando o gene que codifica a LiP0, bem como o plasmídeo e/ou proteína LiP0 utilizando estratégia homóloga (composta de plasmídeo de DNA) e heteróloga (composta de plasmídeo de DNA adicionado a proteína recombinante e CpG), contra a infecção causada por L. chagasi em hamsters. Hamsters foram imunizados e posteriormente infectados com L. chagasi por via endovenosa. Os animais imunizados com a micobactéria, apesar de apresentarem resposta imune humoral anti-M. smegmatis, não produziram anticorpo contra LiP0, que só foram detectados no soro dos animais que receberam a estratégia heteróloga de imunização. Na análise de citocinas, observou-se que os animais imunizados com rM.smegmatis LiP0 apresentaram maior concentração de IFN-γ e menor quantidade de TGF-ß e IL-10 quando comparado aos grupos controle, sugerindo uma resposta Th1. Em diferentes momentos após o desafio, o grau de proteção avaliado pela carga parasitária em órgãos alvo, foi estimado por ensaio de diluição limitante. Nenhuma diferença foi observada na carga parasitaria do baço, fígado e linfonodo em hamsters imunizados ou controles em todos os pontos da avaliação, sugerindo que a LiP0, não protegeu hamsters imunizados tanto com o Mycobacterium expressando o gene que codifica a proteína, nem como vacina de DNA utilizando a estratégia homóloga ou heteróloga contra infecção por L.chagasi.
The acid ribosomal protein of Leishmania infantum (L. infantum) - LiP0 is a structural component of the ribosomal subunit and it was described as an immunodominant antigen recognized either by serum of patients and dogs infected by Leishmania chagasi (L. chagasi) and cooperates in the synthesis of other proteins. Mycobacterium smegmatis (M. smegmatis) is a opportunistic bacteria, which presents rapid growth, is a potent adjuvant and has been used as carrier of antigens in several different experimental models of immunoprotection. In this work we evaluate the immunoprotective capacity of recombinant M. smegmatis (rM. smegmatis) carrying the gene of LiP0 and the DNA or protein of LiP0 using homologous strategy (composed of plasmid DNA) and heterologous (consisting of plasmid DNA and recombinant protein more CpG) to immunize hamsters against infection by L. chagasi. The immunized animals produced anti-M.smegmatis antibodies but they did not produce antibody against LiP0, detected only in animals who received the heterologous strategy of vaccination. In the analysis of cytokines, we observed that animals immunized with rM.smegmatis LiP0 had higher concentration of IFN-γ and lower amounts of TGF-ß and IL-10 compared to control groups, suggesting a Th1 response. At different times after challenge, the degree of protection, evaluated by parasite load in the target organs, was estimated by limiting dilution assay. No difference was observed in the parasite load in the spleen, liver and lymph node between immunized hamsters and controls at all points of evaluation. There was no protection in animals immunized with rM. smegmatis expressing the acidic ribosomal protein gene, suggesting that LiP0 did not protect hamsters immunized with either Mycobacterium expressing the gene encoding the protein or DNA as a vaccine strategy using homologous or heterologous against infection L.chagasi.
Zhou, Wei [Verfasser], and Andreas [Akademischer Betreuer] Burkovski. "Signal transduction in nitrogen control of Mycobacterium smegmatis / Wei Zhou. Gutachter: Andreas Burkovski." Erlangen : Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 2013. http://d-nb.info/107547471X/34.
Full textGebhard, Susanne, and n/a. "The Phn and Pst systems of Mycobacterium smegmatis : phosphate transport and gene regulation." University of Otago. Department of Microbiology & Immunology, 2006. http://adt.otago.ac.nz./public/adt-NZDU20070502.112113.
Full textTadepalli, Adilakshmi. "Studies on the role of salicylic acid in iron metabolism of Mycobacterium smegmatis." Thesis, University of Hull, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310316.
Full textRaphela, Mabule Lucas. "Targeted depletion of RibF, a putative bifunctional FAD synthetase/ flavokinase in Mycobacterium smegmatis using CRISPR interference." Master's thesis, Faculty of Health Sciences, 2020. http://hdl.handle.net/11427/32943.
Full textOLIVEIRA, Renato Antonio dos Santos. "Efeito pós-antibiótico de um novo derivado 1,2,4-oxadiazol-hidrazida e suas associações frente ao Mycobacterium fortuitum e Mycobacterium smegmatis." Universidade Federal de Pernambuco, 2004. https://repositorio.ufpe.br/handle/123456789/1503.
Full textA freqüente resistência das micobactérias atípicas às drogas antituberculose, a ausência de esquemas terapêuticos eficazes e os estudos concernentes à aplicação de novas moléculas sobre micobactérias motivaram a determinação do efeito pós-antibiótico (EPA) in vitro de um novo derivado 1,2,4-oxadiazol-hidrazida (HHBA) e de suas associações com o quimioterápico ofloxacino (OFLO), uma fluorquinolona, e o m-Flúor-Fenilalanina (m-FFen), um inibidor da síntese da parede celular. O EPA foi avaliado após o tempo de contato de 2 e 4 horas frente ao Mycobacterium fortuitum e ao Mycobacterium smegmatis. As drogas foram testadas em concentrações equivalentes a concentração inibitória mínima (CIM). Considerado um parâmetro farmacodinâmico de grande relevância em situações clínicas, o EPA exerce a sua maior importância na escolha do antimicrobiano, nos regimes de dosagem terapêutica e nos seus intervalos de administração. O EPA pode ser induzido pela exposição do microrganismo ao antimicrobiano por um período de tempo determinado, seguindo da rápida retirada deste antimicrobiano, e o acompanhamento do recrescimento deste microrganismo. Matematicamente, o EPA é calculado pela fórmula: EPA= T C, em que T representa o tempo necessário para que a cultura teste cresça o equivalente a 1log10 em relação à numeração efetuada logo após a retirada da droga e C representa o tempo necessário para que a cultura controle cresça igualmente de 1log10. O que concerne ao efeito pós-antibiótico sobre o M. fortuitum após 2 horas de contato a OFLO apresentou os maiores valores de EPA, 8,60 ± 1,50 horas. Todas as associações mostraram-se antagônicas com exceção da HHBA+m-FFen que induziu a um EPA indiferente de 1,20 ± 1,20 horas. Após 4 horas de contato, a OFLO continuou apresentando a melhor atividade cujo EPA foi equivalente a 11,50 ± 2,00 horas, sua associação com a m-FFen apresentou um EPA indiferente de 11,00 ± 2,70 horas. As demais associações apresentaram-se antagônicas. O efeito pós-antibiótico do HHBA frente ao M. smegmatis após um contato de 2 horas foi de 2,40 ± 2,80 horas e a sua associação com a OFLO mostrou ser a mais efetiva cujo valor do EPA foi de 3,30± 2,80 horas. Após 4 horas de contato o EPA do HHBA não foi alterado, permanecendo em 3,30 ± 2,60 horas. O aumento do tempo de contato induziu um aumento dos valores do EPA para as drogas estudadas e suas associações, exceto o m-FFen, as associações OFLO-HHBA e OFLO-HHBA-m-FFen frente ao M. smegmatis, e o HHBA e sua associação HHBA-m-FFen, frente ao M. fortuitum. A ofloxacino foi o antimicrobiano que induziu os melhores valores de EPA para o M. fortuitum, bem como o HHBA foi o antimicrobiano que induziu os melhores valores de EPA para o M. smegmatis. O aumento do tempo de contato de 2 para 4 horas potencializou os EPAs das drogas estudadas.Todas as associações testadas apresentaram um caráter antagônico, exceto a associação OFLO-m-FFen após 4 horas de contato, frente o M. smegmatis. E os tempos de contatos escolhidos, bem como a CMI utilizada para os ensaios, foram insuficientes para que as drogas e suas associações pudessem induzir EPAs sinérgicos. Como os mecanismos do EPA ainda não estão totalmente definidos é difícil lançar hipóteses acerca do qual ou quais mecanismos estão implicados na variação dos resultados dos EPAs de drogas testadas em associação
Jeßberger, Nadja [Verfasser], and Andreas [Akademischer Betreuer] Burkovski. "The GlnR-dependent nitrogen regulatory network of Mycobacterium smegmatis / Nadja Jeßberger. Betreuer: Andreas Burkovski." Erlangen : Universitätsbibliothek der Universität Erlangen-Nürnberg, 2011. http://d-nb.info/1015782132/34.
Full textKovačević, Svetozar. "Characterisation of a Mycobacterium smegmatis transposon mutant with defects in cell envelope mannolipid synthesis." Monash University, Dept. of Microbiology, 2002. http://arrow.monash.edu.au/hdl/1959.1/7670.
Full textHooper, Tracy. "Comparing the metabolism and metabolic capabilities of Mycobacterium smegmatis vs Mycobacterium bovis BCG, using in silico and in vitro analysis methods." Thesis, University of Surrey, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.493043.
Full textDAIM, Sylvia. "Expression of the Mycobacterium tuberculosis PPE37 protein in Mycobacterium smegmatis induces low TNF-α and IL-6 production in murine macrophages." Kyoto University, 2011. http://hdl.handle.net/2433/142100.
Full textKocabas, Evren. "Identification of native co-factors of MshB and MCA from Mycobacterium species." Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/44457.
Full textMaster of Science
Vijay, Srinivasan. "Ultrastructural and Molecular Analyses of the Unique Features of Cell Division in Mycobacterium Tuberculosis and Mycobacterium Smegmatis." Thesis, 2013. http://etd.iisc.ernet.in/2005/3403.
Full textMukherjee, Raju. "Cell Surface Of Mycobacterium Smegmatis At The Stationary Phase : Regulation Of Gene Expression." Thesis, 2007. http://hdl.handle.net/2005/510.
Full textChowdhury, Rakhi Pait. "Newer Insights On Structure, Function And Regulation Of Dps Protein From Mycobacterium smegmatis." Thesis, 2009. http://hdl.handle.net/2005/970.
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