Дисертації з теми "Clostridium difficile toxins"
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Karlsson, Sture. "Toxin production in Clostridium difficile /." Stockholm : Karolinska institutet, 2004. http://diss.kib.ki.se/2004/91-77349-812-2/.
Повний текст джерелаMullan, Nivette K. "Mucosal cell responses to Clostridium difficile toxins." Thesis, University of Nottingham, 2011. http://eprints.nottingham.ac.uk/13217/.
Повний текст джерелаHussack, Greg. "Single-domain Antibody Inhibitors of Clostridium difficile Toxins." Thèse, Université d'Ottawa / University of Ottawa, 2011. http://hdl.handle.net/10393/20362.
Повний текст джерелаShilling, Michael P. "Optimizing detection and control of Clostridium difficile and its toxins." Thesis, Kent State University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3618927.
Повний текст джерелаClostridium difficile infection (CDI) is a bacterial disease affecting the lower gastrointestinal tract of patients whose normal colonic microbiota are altered, generally by administration of antibiotic therapies. C. difficile produces toxins that cause severe diarrhea, with potentially fatal complications in the immunocompromised. CDI has spread unabated despite the best prevention efforts of clinical practitioners. This dissertation is a broad-based study of several factors of importance in prevention and control CDI. In clinical environments, transport media are used to maintain the integrity of clinical samples for later laboratory testing. A transport medium for enteric bacteria was assessed as a preservative in outpatient fecal samples submitted for CDI testing. The transport medium used preserved C. difficile toxin out to five days. The possible effect of fecal pH and trypsin content on toxin stability was investigated. Fecal pH was ruled out as a factor due to CDI selected samples tending toward neutral pH. Trypsin was found to degrade toxin in controlled experiments; however, results from clinical samples were mixed. Oils and fatty acids, including virgin coconut oil (VCO), have antimicrobial effects on a variety of human pathogens. Use of natural products like VCO may reduce or prevent CDI by killing C. difficile while preserving the protective bowel flora. Virgin coconut oil (VCO) and three of its constituent fatty acids were evaluated for their toxic effect on C. difficile and were found to have bactericidal activity, the most potent of which was lauric acid. The outer surface of C. difficile spores is thought to contain proteins that are critical for attachment of the spores to surfaces, including human hands. This strong attachment assists in transmission of infectious spores; however, the source of this strong attachment in the spore remains unknown. Transmission electron micrography shows that C. difficile lacks a true exosporium, rather, they are coated in the remains of the mother cell. Results from subsequent fluorescence microscopy and ELISA with antibodies raised against spore coat proteins confirm that this residue is not part of the spore coat and can be easily removed by chemical treatment, increasing spore binding to anti-coat antibodies.
Shilling, Michael. "OPTIMIZING DETECTION AND CONTROL OF CLOSTRIDIUM DIFFICILE AND ITS TOXINS." Kent State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=kent1374852321.
Повний текст джерелаTsuchiya, Ana Claudia 1987. "Avaliação de métodos e ocorrência de Clostridium difficile em carnes." [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/255444.
Повний текст джерелаDissertação (mestrado) - Universidade Estadual de Campionas, Faculdade de Engenharia de Alimentos
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Resumo: Clostridium difficile é um bacilo anaeróbio responsável por doença intestinal associada ao tratamento prévio com antibióticos, manifestando desde uma diarreia leve até casos graves de colite pseudomembranosa causada principalmente pelas toxinas A (TcdA) e B (TcdB). Os casos de infecção estão relacionados à contaminação em hospitais, porém pesquisas recentes sugerem possível associação ao consumo de alimentos contaminados, pois C. difficile já foi isolado de bovinos, suínos e aves e suas carnes sugerindo os animais como reservatórios. Desta forma, os estudos são de suma importância para o entendimento da transmissão da doença causada por C. difficile. Diante de poucas pesquisas de C. difficile e da inexistência de método padronizado para seu isolamento a partir dos alimentos, o trabalho consistiu em três etapas: 1) avaliação de metodologia [utilizando dois procedimentos (tratamento com álcool e plaqueamento direto) e dois meios seletivos (ágar Clostridium difficile moxalactan norfloxacina ¿ CDMNA e ágar cicloserina cefoxitina frutose ¿ CCFA)] de detecção de C. difficile em carnes (bovina moída e peito de frango [Peitoralis profundus e superficialis]); 2) avaliação da ocorrência de C. difficile em amostras de carnes resfriadas (bovina moída, bovina peça [Semimembranosus], suína [Longuisimus dorsi] e frango [Peitoralis profundus e superficialis]), compreendendo detecção, isolamento e identificação dos isolados; 3) avaliação do perfil toxigênico dos isolados através da detecção de genes tcdA e tcdB codificadores de TcdA e TcdB e respectivamente avaliação de produção do toxinas pelos isolados. A partir da comparação de dois procedimentos, observou-se que o plaqueamento direto foi mais eficaz e recuperou uma maior quantidade de C. difficile se comparado com o tratamento com álcool e o ágar Clostridium difficile moxalactan norfloxacina (CDMNA) apresentou maior taxa de recuperação em relação ao ágar cicloserina cefoxitina frutose (CCFA). A ocorrência de C. difficile foi observada em 11,5% (17/147) das amostras analisadas, totalizando 80 isolados, destes 41,2% (33/83) apresentaram positivo para pelo menos um gene de virulência (A-B+), ou para ambos os genes (A+B+). Houve concordância de 70,5% entre os testes fenotípicos e genotípicos utilizados para detecção de toxinas. Desta forma, sugere-se que alimentos de origem animal são uma potencial fonte de transmissão de C. difficile para humanos
Abstract: Clostridium difficile is an anaerobic bacillus responsible for intestinal deseases in individuals previouslly treated with antibiocs, who can manifest from a mild diarrhea to severe cases of pseudomembranous colitis, mainly caused by toxins A (TcdA) and B (TcdB). The infections are related to contamination in hospitals, but recent researches sugests a possible association with the consumiption of contaminated foods as C. difficile has been isolated from bovines, suines and poultries and their meat, sugesting animals as reservatories. Thus, studies are extremelly important to elucidate the transmition of the desease caused by C. difficile. Faced with few researches about this bacteria and the lack of a standard method for its isolation from food, this work is divided in three steps: 1) Evaluation of the methodology for C. difficile detection in meet (commercial bovine mince and chicken breast ¿ [Peitoralis superficialis and Peitoralis profundus] [using two procedures (treatment with alcohol and direct plating) and two selective mediums (agar Clostridium difficile moxalactan norfloxacin ¿ CDMNA and cycloserine cefoxitin fructose agar¿ CCFA)]; 2) Assessing of the occurrence of C. difficile in samples of chilled meat (bovine: commercial mince and the whole Semimembranosus; suine: whole Longuisimus dorsi; chicken: Peitoralis profundus and Peitoralis superficialis) by detection, isolation and identification of the isolated; 3) Evaluation of the toxicogenic profile of the isolated by the detection of the genes tcdA and tcdB, which are encoding of TcdA and TcdB respectivelly, and the capacity of toxine production by the isolated bacterias. From the comparison of the two proceeding above it was observed that the direct plating was more efficient and recovered a larger aumont of C. difficile than the treatment with alcohol. Furthermore, the CDMNA agar presented a higher recovery rate compared to CCFA agar. It was observed the occurrence of C. difficile in 11,5% (17/147) of the analyzed samples, comprising 80 isolates, of which 41,2% (33/83) showed a positive response for at least one virulence gene (A-B+), or for both genes (A+B-). In addition, there was a 70,5% concordance between the phenotypic and genotypic tests used to detect toxins. In this way, it is suggested that foods of animal origin are a potential source of transmission of C. difficile for humans
Mestrado
Tecnologia de Alimentos
Mestre em Tecnologia de Alimentos
Davies, Abigail. "Structure and biochemical analysis of toxins from the superbug Clostridium difficile." Thesis, University of Bath, 2014. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.619282.
Повний текст джерелаMartinez, Ramon D. "Purification and characterization of Clostridium sordellii toxins HT and LT and comparison to toxins A and B of Clostridium difficile." Diss., Virginia Polytechnic Institute and State University, 1989. http://hdl.handle.net/10919/54238.
Повний текст джерелаPh. D.
Vohra, Prerna. "Clostridium difficile : expression of virulence factors, resistance to disinfectants and interactions with human cells." Thesis, University of Edinburgh, 2012. http://hdl.handle.net/1842/6490.
Повний текст джерелаJefferson, Kimberly Kay. "Clostridium difficile toxins A and B: exploring the possible mechanism of action." Thesis, Virginia Tech, 1995. http://hdl.handle.net/10919/45056.
Повний текст джерелаClostridium difficile is a common cause of antibiotic-associated diarrhea and
occasionally causes the life-threatening disease pseudomembranous colitis. The
pathogenicity of the organism has been attributed to the production of two large
exotoxins, toxin A (308,000 daltons) and toxin B (269,000 daltons). Toxin A is a
powerful enterotoxin and is generally thought to play the more important role in the
pathology of the disease. Toxin B may exert its effect after the initial tissue damage by
toxin A. Both toxins cause rounding of mammalian culture cells by disrupting the
cytoskeletal system. The similar biological activities and high percentage of sequence
homology between the two toxins suggest that they have a similar mechanism of action.
I found that purified preparations of both toxins cleave skeletal muscle actin at a single
site, producing a 38,000 dalton actin fragment, and that the toxins are capable of
autodigestion. The proteolytic activity may be involved in the mechanism of action of
the toxins. I also analyzed an aberrant strain of C. difficile which reportedly lacked the
gene for toxin B. Such a strain would be very useful for the study of the mechanism of
toxin A. I concluded however, that the strain contained the genes for both toxin A and
toxin B. The toxin genes and resulting proteins appear, however, to be slightly different
from those of other strains.
Master of Science
Lewallen, Daniel M. "Development of synthetic carbohydrates for capturing toxins." University of Cincinnati / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1288969515.
Повний текст джерелаBarroso, Lisa Ann. "Effect of Autoregulated TxeR on the Expression of Clostridium difficile Toxins." Thesis, Virginia Tech, 1999. http://hdl.handle.net/10919/35988.
Повний текст джерелаExpression levels of ARU from the toxin B promoter region with TxeR supplied on the same plasmid (in cis) or on a different plasmid (in trans) were determined. In cis, ARU levels were 50-fold higher than strains without txeR. In trans, expression of ARU from the toxin B promoter region increased over 800-fold. When TxeR was supplied in trans to a toxin A promoter region-ARU fusion, expression levels of ARU increased over 500-fold. To test for autoregulation, TxeR was supplied in trans to the txeR promoter region fused to ARU. The effect was an increase of ARU expression up to 20-fold over background. These results suggest that TxeR is a trans-acting regulator that stimulates expression of the C. difficile toxins and is subjected to autoregulation.
Master of Science
Strysio, Oliver Moritz [Verfasser]. "Molecular characterization of single-domain antibodies against Clostridium difficile toxins / Oliver Moritz Strysio." Hamburg : Staats- und Universitätsbibliothek Hamburg Carl von Ossietzky, 2020. http://d-nb.info/1223621030/34.
Повний текст джерелаMonaghan, Tanya Marie. "Circulating antibody and memory B cell responses to Clostridium difficile toxins A and B." Thesis, University of Nottingham, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.595681.
Повний текст джерелаGustafsson, Agneta. "Antibiotic associated diarrhea in horses : with special reference to Clostridium difficile /." Uppsala : Dept. of Large Animal Clinical Sciences, Swedish Univ. of Agricultural Sciences, 2004. http://epsilon.slu.se/v166.pdf.
Повний текст джерелаKasendra, Magdalena Julia <1985>. "Clostridium difficile toxins facilitate bacterial colonization by modulating the fence and gate function of colonic epithelium." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6364/.
Повний текст джерелаHammond, Georgia Ann. "The toxigenic element of Clostridium difficile strain 10463 and its transcriptional analysis in strains which differ in toxigenicity." Diss., Virginia Tech, 1994. http://hdl.handle.net/10919/37447.
Повний текст джерелаPh. D.
Du, Timothy. "Use of an in-vitro polarized cell culture model to study the translocation of Clostridium difficile toxins." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0011/MQ41694.pdf.
Повний текст джерелаZhu, Ziyu [Verfasser]. "Bacitracin reduces the cytotoxic effects of Clostridium difficile toxins A and B on mammalian cells and human intestinal organoids / Ziyu Zhu." Ulm : Universität Ulm, 2021. http://d-nb.info/1228439109/34.
Повний текст джерелаPerelle, Sylvie. "Toxine IOTA de "Clostridium perfringens" et toxines apparentées." Paris 11, 1996. http://www.theses.fr/1996PA114811.
Повний текст джерелаTicchi, Laurence. "Clostridium difficile et ses toxines : prévalence de "Clostridium difficile" et de la toxine A asymptomatique." Paris 5, 1990. http://www.theses.fr/1990PA05P183.
Повний текст джерелаCosmetatos, Isabelle Cosmetatos Isabelle. "Fecal isolation of "Clostridium difficile" and its toxins in horses with typhlo-colitis : Oral administration of neomycin and phthalylsulfathiazole in horses : effects on clinical, hematological and hematochemical parameters and influence on the isolation rate of "C. difficile" in feces /." [S.l.] : [s.n.], 1995. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.
Повний текст джерелаKerzmann, Amy N. "Mechanistic analysis of Clostridium difficile toxin A." [Bloomington, Ind.] : Indiana University, 2009. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3378359.
Повний текст джерелаTitle from home page (viewed on Jul 12, 2010). Source: Dissertation Abstracts International, Volume: 70-10, Section: B, page: 6182. Advisers: Andrew L. Feig; James T. Drummond.
Almdni, Sabir M. Shakir. "Recombinant antibodies against Clostridium difficile toxin A." Thesis, University of Glasgow, 2013. http://theses.gla.ac.uk/4727/.
Повний текст джерелаLim, Chien-Sen Jenson. "Functional studies of toxin A from Clostridium difficile." Thesis, Imperial College London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.407433.
Повний текст джерелаCraggs, Joanna K. "Structure-function relationships of Clostridium difficile toxin A." Thesis, University of Nottingham, 1999. http://eprints.nottingham.ac.uk/12047/.
Повний текст джерелаBurger, Silke. "Darstellung und Charakterisierung von rekombinantem Clostridium-difficile-Toxin A." [S.l.] : [s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=974133590.
Повний текст джерелаAgoumellah, Fatiha. "Pathologie de Clostridium difficile chez le nourrisson de moins d'un an." Paris 5, 1998. http://www.theses.fr/1998PA05P199.
Повний текст джерелаFrey, Steven M. "The localization of two epitopes recognized by the monoclonal antibody PCG-4 on toxin A of Clostridium difficile." Thesis, This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-05022009-040613/.
Повний текст джерелаKrencker, Diane. "Diarrhees associees a la presence de clostridium difficile et/ou de sa toxine : a propos de 76 cas." Université Louis Pasteur (Strasbourg) (1971-2008), 1991. http://www.theses.fr/1991STR1M188.
Повний текст джерелаBALDACINI, OLIVIER. "La cytotoxine de clostridium sordellii. Etude comparee a la toxine b de clostridium difficile." Université Louis Pasteur (Strasbourg) (1971-2008), 1992. http://www.theses.fr/1992STR13037.
Повний текст джерелаCavalcante, Ingrid Chaves. "Study of a new adenosine receptor A2A agonist, ATL313, on Clostridium difficile toxin A-induced enteritis in ileal pouch isolated of mice." Universidade Federal do CearÃ, 2005. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=84.
Повний текст джерелаC. difficile toxin A (TxA) plays an important pathogenic role in antibiotic-induced diarrhea and pseudomembranous colitis, a condition characterized by intense mucosal inflammation and secretion. Agonist activity at A2A adenosine receptors (A2A ARs) attenuates inflammation and damage in many tissues. This study evaluated the effect of a new selective A2A AR agonist (4-{3-[6-amino-9-(5-cyclopropylcarbamoyl-3,4-dihydroxytetrahydrofuran-2-yl)-9H-purin-2-yl]prop-2-ynyl}piperidine-1-carboxylic acid methyl ester; ATL313) on TxA-induced enteritis in murine ileal loops. ATL313 (0.05-5 nM) and/or the A2A AR antagonist (ZM241385; 5 nM) or PBS were injected inside ileal loops immediately prior to challenge with TxA (1-10 mg/loop) or PBS. Intestinal fluid volume/length and weight/length ratios were calculated 3 h later. Ileal tissue samples were collected for measurement of myeloperoxidase (MPO) content, evaluation of ADA activity, for histopathology and apoptotic immunohistochemistry (ApopTagÃ) and for assessment of TNF-α levels by ELISA. TxA (1-10 Âg/loop) significantly (p<0.05) increased volume/length and weight/length, reaching maximum values at 5Âg/loop dosage. ATL313 (5 nM) treatment significantly (p<0.05) reduced TxA-induced volume/length and weight/length, as well as prevented mucosal disruption and TxA-induced apoptosis. These protective effects were reversed by ZM241385 (5 nM), the A2A AR antagonist. ATL313 (5 nM) also reduced neutrophil infiltration, as measured by MPO content; reduced the toxin A-induced increase in ADA activity. Prior to the challenge with TxA, a systemic injection of fucoidin, but not PBS, also reduced tissue destruction and toxin A-induced increase in ADA activity. In conclusion, the A2A AR agonist ATL313 has a great antiinflammatory effect in TxA-induced mice enteritis, significantly reducing tissue destruction and ADA activity. In addition, our data suggested that TxA-induced increase in ADA activity and tissue damage in murine ileal loops are related to the neutrophil infiltration induced by this toxin.
A toxina A do Clostridium difficile (TxA) desempenha um importante papel na patogÃnese da diarrÃia induzida por antibiÃticos e na colite pseudomembranosa, uma condiÃÃo caracterizada por intensa secreÃÃo e inflamaÃÃo da mucosa. A estimulaÃÃo de receptores A2A da adenosina reduz a inflamaÃÃo e o dano tecidual. Neste estudo, avaliou-se o efeito de um novo agonista seletivo para receptores A2A da adenosina (metil Ãster do Ãcido 4-{3-[6-amino-9-(5-ciclopropilcarbamoil-3,4- dihidroxitetrahidrofuran-2-il)-9H-purin-2-il]prop-2-inil}piperidina-1-carboxÃlico; ATL313) na enterite induzida pela TxA em alÃas ileais de camundongos. O ATL313 (0,05-5 nM) e/ou o antagonista dos receptores A2A da adenosina (ZM241385; 5 nM) ou PBS foram injetados em alÃas ileais imediatamente antes da injeÃÃo de TxA (1-10 Âg/alÃa) ou PBS. As razÃes volume de secreÃÃo/comprimento da alÃa e peso/comprimento da alÃa foram calculadas 3h depois. Amostras de tecido foram coletadas para dosagem de atividade de mieloperoxidade (MPO), atividade de ADA, histopatologia, imunohistoquÃmica para apoptose (ApopTag_) e dosagem de TNF-a_ por ELISA. A injeÃÃo de TxA (1-10 Âg) nas alÃas ileais aumentou significativamente (p<0,05) as razÃes volume de secreÃÃo/comprimento da alÃa e peso/comprimento da alÃa com pico em 5Âg. O tratamento das alÃas com ATL313 (5 nM) reduziu significativamente (p<0,05) a secreÃÃo e o edema, preveniu a destruiÃÃo da mucosa e a apoptose induzidos por TxA. Tais efeitos protetores foram revertidos pelo antagonista dos receptores A2A de adenosina, o ZM241385 (5 nM). O tratamento com ATL313 (5 nM), reduziu ainda a infiltraÃÃo neutrofÃlica, avaliada pela dosagem de MPO, e reduziu o aumento da atividade de ADA induzidos pela TxA, bem como a dosagem de TNF-a no tecido das alÃas ileais. O prÃ-tratamento sistÃmico com fucoidina, mas nÃo com PBS, tambÃm reduziu o dano na mucosa e atividade de ADA no tecido das alÃas ileais tratadas com TxA. Assim, conclui-se que na enterite induzida pela TxA em camundongos, o agonista dos receptores A2A da adenosina (ATL313) possui um potente efeito antiinflamatÃrio, reduzindo consideravelmente a lesÃo tecidual e a atividade de ADA. Nossos resultados tambÃm indicam que o aumento da atividade de ADA e o dano tecidual induzido pela TxA em alÃa ileal de camundongos està relacionado com a infiltraÃÃo neutrofÃlica induzida por esta toxina.
Santos, Ana Angélica Queiroz Assunção. "Estudo das alterações morfológicas induzidas pela Toxina A, do Clostridium difficile em células epiteliais intestinais e do efeito protetor da Glutamina e Alanil-glutamina." reponame:Repositório Institucional da UFC, 2011. http://www.repositorio.ufc.br/handle/riufc/6909.
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Clostridium difficile is the major cause of antibiotic-associated colitis, a disease with significant morbidity and mortality. Glutamine (Gln), a non-essential aminoacid, is a major fuel for the dynamic intestinal cell population. Alanyl-glutamine (Ala-Gln) is a dipeptide that is highly soluble and well tolerated. The aim of this study was to analyze the changes induced by Clostridium difficile toxin A (TcdA) in intestinal epithelial cell morphology and cytoskeletal element and the effect of Gln and Ala-Gln treatment, using advanced microscopic techniques. Twelve well cell culture plates, with 13 mm diameter glass coverlids, were seeded with 5x105 IEC-6 cells and grown for 24h in DMEM media. Afterwards, the wells were incubated for 24h as follow: control, TcdA (10 ng/mL), TcdA + Gln (10 mM) and TcdA + Ala-Gln (10 mM). The cells were than fixed in 4% formaldehyde for 14 h and afterwards they were examined by atomic force microscopy (AFM), scanning electronic microscopy (SEM) and Fluorescent microscopy. For the SEM the samples were fixed to samples holders with carbon adhesive tape and covered with a 15 mm gold film for conductivity by sputter. To fluorescent microscopy the cells were permeabilizided with PBS/Triton after that they were marked with stained with FITC-RhoA, Rodhamine-phallodin and DAPI performed using an inverted fluorescence microscope. An immunoblotting was realized with the same groups. The PVDF membrane was incubated with RhoA antibody overnight and afterwards activated by Amershan kit. The proteic control was made by α- tubulin. Also performed experiments of cellular proliferation and oxidative stress. As observed by AFM, SEM and Fluorescent microscopy TcdA caused intense cell shrinkage with multiple extensions. This change in shape was associated with collapse of the F-actin cytoskeleton demonstrated by fluorescent microscopy. An increase of RhoA production was detected in the groups treated with Gln e Ala-Gln. We demonstrated that TcdA dramatically altered the intestinal cell morphology and cytoskeleton organization and that Ala-Gln and Gln supplementation consistently prevented the intestinal epithelial cell damage induced by TcdA probably by increasing RhoA expression. The TcdA induced a reduction of 8.4% in cell proliferation while the Ala-Gln and Gln increased by 13.2% and 12.7%, respectively. The TcdA induced cells to oxidative damage, which was reversed by the use of Gln and Ala-Gln.. Our findings provide rationale for the potential use of Ala-Gln and Gln as adjuvant therapy in Clostridium difficile disease. Investigation of morphological and cytoskeleton changes using advanced microscopic techniques may aid in the evaluation of the protective or therapeutic activity of drugs against TcdA effects.
Clostridium difficile é a maior causa de colite associada ao uso de antibióticos, com significante morbidade e mortalidade. Glutamina (Gln), um aminoácido não-essencial, é a maior fonte combustível para a dinâmica das células intestinais. Alanil-glutamina (Ala-Gln) é um dipeptídeo, altamente solúvel e bem tolerado. O objetivo deste estudo foi analisar as alterações induzidas pela toxina A (TcdA) do Clostridium difficile na morfologia e elementos do citoesqueleto das células epiteliais intestinais e o efeito do tratamento com Gln e Ala-Gln, utilizando técnicas avançadas de microscopia. Placas de cultura de células com doze poços, previamente acrescidas de lamínulas de vidro, com diâmetro de 13mm, IEC-6, 5x105 foram semeadas e cultivadas por 24 horas em meio DMEM. Depois, as células foram incubadas por 24h de acordo com os seguintes grupos: Controle, TcdA (10 ng / mL), TcdA + Gln (10 mM) e TcdA + Ala-Gln (10 mM). As células foram fixados em formol a 4% por 14h, depois foram examinados na microscopia de força atômica (AFM), microscopia eletrônica de varredura (SEM), microscopia confocal e fluorescente. Para o SEM as amostras foram fixadas em porta amostras fita adesiva de carbono e cobertos com uma película de ouro 15 mm para adquirir condutividade por pulverização catódica. Para microscopia de fluorescência e o confocal, as células foram permeabilizadas com PBS/Triton depois foram marcados com RhoA- FITC, Faloidina –Rodamina e DAPI e as imagens capturadas através de um microscópio invertido de fluorescência ou confocal. Um immunoblotting foi realizado com os mesmos grupos. A membrana PVDF foi incubada com o anticorpo RhoA overnight, em seguida ativado pelo kit Amershan. O controle protéico foi feito por α-tubulina. Também realizarmos experimentos de proliferação celular e estresse oxidativo. Observou-se que a TcdA causa intenso encolhimento celular restando múltiplas extensões filamentosas. Esta alteração na forma foi associada ao colapso do citoesqueleto de F-actina demonstrada na microscopia de fluorescência. Um aumento da produção RhoA foi detectada no grupo tratado com Gln e Ala-Gln. Demonstramos que a morfologia das células intestinais e organização do citoesqueleto foram dramaticamente alteradas pela TcdA e que a suplementação com Ala-Gln e Gln impediu o dano celular epitelial intestinal induzida pela TcdA provavelmente por aumentar a expressão RhoA. A TcdA induziu uma redução de 8,4% na proliferação celular, enquanto o Ala-Gln e Gln aumentou 13,2% e 12,7%, respectivamente. A TcdA induziu as células ao dano oxidativo, que foi revertido com o uso de Gln e Ala-Gln. Nossos resultados fornecem justificativa para o uso potencial de Ala-Gln e Gln como terapia adjuvante na doença causada pelo Clostridium difficile. Investigação de alterações morfológicas e citoesqueleto usando avançadas técnicas de microscopia pode auxiliar na avaliação da atividade de proteção ou terapêutica de drogas contra os efeitos TcdA.
El, Meouche Imane. "Etude du régulateur transcriptionnel SigmaD chez Clostridium difficile." Rouen, 2014. http://www.theses.fr/2014ROUES008.
Повний текст джерелаThe main part of this work focuses on the characterization of the C. Difficile SigD factor and its role in the regulation of autolysis, motility and production of the two major virulence factors, toxins A and B. After the inactivation of sigD, we show that SigD factor positively controls C. Difficile motility whereas its contribution to the autolysis, if any, is modest. The global regulon of SigD was then determined by transcriptonic analysis using microarrays. Among the down-regulated genes in the sigD mutant strain, we find the late flagellar genes, the genes encoding toxins A and B and the gene encoding their regulator TcdR. We could identify SigD-dependent promoters upstream many genes including those encoding the flagellin FliC, the anti-SigD FlgM, and TcdR. In addition, we proved that SigD binds with RNA polymerase to initiate the transcription of tcdR. Furthermore, we identified a specific SigD-dependent consensus sequence in C. Difficile. Finally, we determined the antagonistic role of FlgM, the anti-SigD, in the repression of SigD-dependent genes. We prove that SigD is a positive and direct regulator of motility and toxin synthesis in C. Difficile. Another part of the work focuses on the autolysins Cwp19 and Acd of C. Difficile. Single mutants for acd and cwp19 genes showed that only Cwp-19 is involved in the long-term lysis of C. Difficile. A double-mutant acd-cwp19 seems to have the same autolytic profile as cwp19 single mutant. The glucosaminidase Acd does not seem to have a major involvement in autolysis of C. Difficile. Additional analyzes are in progress to determine the enzymatic activity of the Cwp19 autolysin
Sekulovic, Ognjen. "Étude de l'impact des prophages sur la biologie de Clostridium difficile." Mémoire, Université de Sherbrooke, 2010. http://savoirs.usherbrooke.ca/handle/11143/4049.
Повний текст джерелаSIFFERT, JEAN-CLAUDE. "Le cytotoxine ou toxine b de clostridium difficile : actions sur le systeme des phagocytes mononuclees : implication physiopathologique." Besançon, 1991. http://www.theses.fr/1991BESA3090.
Повний текст джерелаFoschetti, Danielle Abreu. "Toxinas A e B do Clostridium difficille induzem a expressão diferencial de receptor de Adenosina em células epiteliais intestinais: papel do receptor A2B." reponame:Repositório Institucional da UFC, 2014. http://www.repositorio.ufc.br/handle/riufc/14909.
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Clostridium difficile is recognized to be a nosocomial pathogen that causes intense intestinal inflammation, epithelial barrier disruption and diarrhea. Adenosine production is increased under inflammatory situations. The adenosine receptor A2B is the most expressed receptor in the human and mice intestine. We investigated the effect of short- and long-term exposure to TcdA and TcdB in HCT-8 cells and isolated cecum epithelial cells. HCT-8 cells were exposed to TcdA or TcdB (10 ng/ml) for 2, 6 and 24h. We used a murine cecal loop model and murine infection model to evaluate the effects of TcdA and C. difficile infection, respectively. We demonstrated that HCT-8 and isolated intestinal cecum epithelial cells naturally express high levels of A2BR receptors. TcdA or TcdB alters the cell morphology, viability and proliferation pattern and caused gene expression increase of all AR subtypes in HCT-8. In isolated cecum epithelial cells, TcdA significantly (p<0.05) increased volume/length, weight/length, histopathology scores, neutrophil infiltration, as measured by MPO content, and induced an altered gene expression increase of all AR subtypes. PSB603 (10 nM) treatment significantly (p<0.05) reduced TcdA-induced tissue damage. Our findings support the hypothesis that Clostridium difficile toxins affect adenosine receptor expression and this action may be related to their severe inflammatory effect. We concluded that adenosine receptors may play a crucial role in regulating the inflammatory system in intestinal epithelium during C. difficile infection.
O Clostridium difficile é reconhecido por ser uma bactéria nosocomial, levando a intensa inflamação intestinal, quebra da barreira epitelial e diarreia. A produção de adenosina está aumenta durante eventos inflamatórios. O receptor de adenosina A2B (A2BR) é o mais expresso no intestino de humanos e camundongos. Nós investigamos o efeito de exposição às TcdA e TcdB, a curto e longo prazo, em células HCT-8 e células epiteliais intestinais isoladas do ceco. Células HCT-8 foram expostas a TcdA ou TcdB (10 ng/ml) por 2, 6 e 24h. Foi usado o modelo de alça cecal e de infecção pelo bacilo em murinos para avaliar os efeitos da TcdA e da infecção pelo C. difficile, respectivamente. Foi demonstrado que HCT-8 e células epiteliais intestinais isoladas do ceco naturalmente expressam altos níveis do receptor A2BR. TcdA e TcdB alteraram a morfologia celular, viabilidade e proliferação e causaram aumento da expressão gênica de todos os subtipos de receptores de adenosina e das citocinas IL-6 e IL-8 em HCT-8. Em células epiteliais intestinais isoladas do ceco, a TcdA significativamente causou um aumento do peso e volume/comprimento da alça cecal, escores histológicos e infiltrado neutrofílico, medido por MPO, e também causou alterações da expressão gênicas dos receptores de adenosina, tanto no modelo de alça cecal quanto na infecção pelo bacilo. O tratamento com PSB603, um antagonista do receptor A2BR, foi capaz de reverter os efeitos causados pelas toxinas do C. difficile. Nossos dados suportam a hipótese que as toxinas do C. difficile alteram a expressão dos receptores de adenosina e isso pode estar relacionado com os severos efeitos inflamatórios. Nós concluimos que os receptores de adenosina tenham um papel importante na regulação da inflamação em células epiteliais intestinais na infecção pelo C. difficile.
Lister, Michelle M. "Understanding the genetic mechanisms of Clostridium difficile toxin regulation and clinical relapse." Thesis, University of Nottingham, 2018. http://eprints.nottingham.ac.uk/53216/.
Повний текст джерелаTrombert, Sabine. "Acquisition de "Clostridium difficile" chez le nouveau-né et cinétique d'implantation." Paris 5, 1995. http://www.theses.fr/1995PA05P087.
Повний текст джерелаBeaudoin, Axelle. "Développement et application d'un test ELISA pour l'étude des anticorps dirigés contre clostridium difficile." Mémoire, Université de Sherbrooke, 2009. http://savoirs.usherbrooke.ca/handle/11143/3958.
Повний текст джерелаMeessen-Pinard, Mathieu. "Caractérisation de phages tempérés et évaluation de leurs impacts sur le phénotype bactérien de clostridium difficile." Mémoire, Université de Sherbrooke, 2010. http://savoirs.usherbrooke.ca/handle/11143/4053.
Повний текст джерелаSolomon, Katie. "An investigation into the effects of purified Clostridium difficile toxin A on monocytes." Thesis, University of Nottingham, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.401583.
Повний текст джерелаJunqueira, Ana FlÃvia Torquato de AraÃjo. "Estudo do efeito do inibidor da enzima adenosina desaminase, EHNA, sobre a enterite induzida pela toxina a do Clostridium difficile em alÃa ileal isolada de camundongos." Universidade Federal do CearÃ, 2008. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=1305.
Повний текст джерелаO Clostridium difficile tem como principal fator de virulÃncia a toxina A (TxA), a qual provoca inflamaÃÃo e destruiÃÃo tecidual aguda em intestinos de animais experimentais e de pacientes com a doenÃa induzida por esta bactÃria. Em locais de injÃria tecidual, adenosina à produzida em altas concentraÃÃes, onde exerce uma sÃrie de efeitos antiinflamatÃrios, limitados por sua rÃpida degradaÃÃo pela enzima adenosina desaminase. O objetivo deste trabalho foi investigar o efeito da inibiÃÃo da enzima adenosina desaminase pelo EHNA (eritro-9-(2-hidrÃxi-3-nonil)-adenina) sobre a enterite induzida pela TxA do C. difficile em alÃa ileal de camundongos. Para isto, injetamos EHNA (90 μmol/kg) ou PBS i.p. 30 minutos antes da administraÃÃo de TxA (10 a 100 μg) ou PBS na alÃa ileal isolada. Os animais foram sacrificados 3 horas depois da induÃÃo da enterite e as alÃas foram retiradas para estudo. As razÃes peso/comprimento da alÃa e volume de secreÃÃo/comprimento da alÃa foram calculadas e amostras de tecido foram coletadas para histopatologia, dosagem de atividade de mieloperoxidase (MPO), dosagem de TNF-α, IL-1β e IL-10 por ELISA, imunohistoquÃmica para TNF-α, IL-1β, NOS induzÃvel e PTX3, e PCR para TNF-α, IL-1β e PTX3. A injeÃÃo de TxA (10 a 100 μg) nas alÃas ileais aumentou significativamente (p<0,05) as razÃes peso/comprimento da alÃa e volume de secreÃÃo/comprimento da alÃa com resultados consistentes a partir de 50 μg. A TxA promoveu significativa (p<0,05) destruiÃÃo tecidual, edema, infiltraÃÃo de cÃlulas inflamatÃrias, aumento das citocinas TNF-α e IL-1β, e elevaÃÃo de iNOS e PTX3. Todos esses parÃmetros foram significativamente revertidos com o uso do EHNA (p<0,05). Em adiÃÃo, a TxA nÃo alterou os nÃveis de IL-10 em relaÃÃo ao controle, mas o prÃ-tratamento com EHNA promoveu uma elevaÃÃo nos nÃveis desta citocina. Assim, concluÃmos que na enterite induzida pela TxA em camundongos o EHNA demonstrou um potente efeito antiinflamatÃrio, reduzindo consideravelmente a lesÃo tecidual, a migraÃÃo neutrofÃlica, a expressÃo e os nÃveis de citocinas prÃinflamatÃrias (TNF-α, IL-1β) e produzindo um aumento nos nÃveis de IL-10. AlÃm disso, a administraÃÃo de TxA induziu um aumento na expressÃo da proteÃna PTX3 e no nÃmero de cÃlulas imunomarcadas para iNOS no tecido ileal, ambos revertidos pelo EHNA
The main factor of virulence in Clostridium difficile is toxin A (TxA), which can induce inflammation and acute tissue injury in the bowels of animals and humans affected by this organism. The high concentration of adenosine generated upon injury produces a number of antiinflammatory effects limited by rapid degradation by adenosine deaminase. The objective of this study was to determine the effect of EHNA (erythro-9-(2-hydroxy-3-nonyl)-adenine) inhibition of adenosine deaminase upon TxA-induced ileal loop enteritis in mice. EHNA (90 μmol/kg) or PBS was injected i.p. 30 minutes prior to TxA (10-100 μg) or PBS instillation into the ligated ileal loop. The animals were euthanized 3 hours after enteritis induction and the ileal loops were retrieved for analysis. The weight/length ratio and the secretion volume/length ratio were calculated and tissue samples were submitted to histopathological study, myeloperoxidase assay (MPO), measurement of TNF-α, IL-1β and IL-10 levels with ELISA, immunohistochemical tests for TNF-α, IL-1β, inducible NOS and PTX3, and PCR assay for TNF-α, IL-1β and PTX3. The instillation of TxA (10-100 μg) into the ileal loop significantly increased (p<0.05) the weight/length ratio and the secretion volume/length ratio with consistent results above 50 μg. TxA induced a significant amount (p<0.05) of histological damage, edema and inflammatory cell infiltration and increased the production of TNF-α, IL-1β, iNOS and PTX3. All changes were significantly reverted by treatment with EHNA (p<0.05). Moreover, IL-10 levels remained unchanged in animals treated with TxA, but increased in animals receiving EHNA. In conclusion, in mice with TxA-induced enteritis EHNA produced considerable antiinflammatory effects, reducing tissue injury, neutrophil migration, the expression and levels of proinflammatory cytokines (TNF-α and IL-1β) and producing an increase in IL-10 levels. In addition, TxA instillation increased PTX3 expression and the number of cells immunolabeled for iNOS in the ileal tissue, both of which were reverted by EHNA
Sirard, Stéphanie. "Analyse génotypique et phénotypique d'isolats cliniques de Clostridium difficile et comparaison en fonction de la sévérité des symptômes." Mémoire, Université de Sherbrooke, 2011. http://hdl.handle.net/11143/5547.
Повний текст джерелаLima, Bruno Bezerra. "Efeitos das toxinas A e B do Clostridium difficile sobre a via de WNT/Beta-catenina em células epiteliais intestinais." reponame:Repositório Institucional da UFC, 2014. http://www.repositorio.ufc.br/handle/riufc/12264.
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Clostridium difficile toxins A and B (TcdA and TcdB) are homologous glycosyltransferases that inhibit a group of small GTPases within host cells, but several mechanisms underlying their pathogenic activity remain unclear. Here, we evaluated the effects of TcdA and TcdB on the Wnt/Beta-catenin pathway, the major driving force behind the proliferation of epithelial cells in colonic crypts. IEC-6 and RKO cells stimulated with Wnt3a-conditioned medium were incubated with 10, 50 and 100 ng/mL of TcdA or TcdB for 24h, resulting in a dose-dependent inhibition of the Wnt signaling, as demonstrated by a T-cell factor (TCF) reporter assay. This was further confirmed by immunofluorescence staining for nuclear localization of Beta-catenin and western blotting for Beta-catenin and c-Myc (encoded by a Wnt target gene). Moreover, our western blot analysis showed a decrease in the Beta-catenin protein levels, which was reversed by z-VAD-fmk, a pan-caspase inhibitor. Nonetheless, TcdA was still able to inhibit the Wnt/Beta-catenin pathway even in the presence of z-VAD-fmk, lithium chloride (a GSK3B inhibitor), or constitutively active Beta-catenin, as determined by a TCF reporter assay. Furthermore, pre-incubation of RKO cells with TcdA for 12h also attenuated Wnt3a-mediated activation of Wnt signaling, suggesting that inactivation of Rho GTPases plays a significant role in that inhibition. Taken together, these findings suggest that attenuation of the Wnt signaling by TcdA and TcdB is important for their anti-proliferative effects.
As toxinas A e B do Clostridium difficile (TcdA e TcdB) são glicosiltransferases homólogas que inibem um grupo de pequenas GTPases dentro da célula hospedeira, contudo, vários mecanismos envolvidos na atividade patogênica dessas toxinas permanecem desconhecidos. No presente estudo, avaliamos os efeitos das TcdA e TcdB na via de Wnt/Beta-catenina que representa a força motora principal responsável pela proliferação das células epiteliais nas criptas colônicas. Foram utilizadas células IEC-6 (células epiteliais de criptas de Rattus novergicus) e RKO (células de adenocarcinoma de cólon humano). Estas células foram estimuladas com meio condicionado contendo Wnt3a e incubadas com 10, 50 ou 100 ng/mL de TcdA ou 1, 5 ou 10 ng/mL de TcdB por 24h, resultando em uma inibição dose-dependente da via de sinalização canônica de Wnt, como demonstrado pelo ensaio de repórter de fator de célula T (TCF). Esse resultado foi corroborado pelos dados da imunofluorescência com marcação para a localização nuclear de Beta-catenina e por western blotting para Beta-catenina e c-MYC (gene-alvo da via de Wnt). Além disso, os dados do experimento de western blot evidenciaram uma diminuição dos níveis da proteína Beta-catenina, o qual foi prontamente revertido por z-VAD-fmk, um pan-inibidor de caspase. Entretanto, a TcdA ainda foi capaz de inibir a via de Wnt/Beta-catenina mesmo na presença do z-VAD-fmk, cloreto de lítio (um inibidor de GSK3Beta) ou plasmídeo de Beta-catenina constitutivamente ativo, como determinado pelo ensaio do TCF (TOPFlash/Luciferase). O estudo evidenciou ainda que a pré-incubação de células RKO com TcdA por 12h também atenuou a ativação da via de Wnt mediada por Wnt3a, o que sugere que a inativação de RhoGTPases, particularmente Rac1, possui um papel nessa inibição. Em conclusão, esses achados sugerem que a inibição da via canônica de Wnt pelas TcdA e TcdB representa um mecanismo importante da sua patogênese e explica seus efeitos anti-proliferativos.
Gauckler, Philipp Alexander [Verfasser]. "Identifizierung inhibitorischer Peptide gegen die Toxine von Clostridium difficile aus humanem Hämofiltrat / Philipp Alexander Gauckler." Ulm : Universität Ulm, 2018. http://d-nb.info/1162193549/34.
Повний текст джерелаMaikova, Anna. "The CRISPR-Cas system of human pathogen Clostridium difficile : function and regulation." Thesis, Université de Paris (2019-....), 2019. http://www.theses.fr/2019UNIP7091.
Повний текст джерелаClostridium difficile (the novel name – Clostridioides difficile) is a Gram-positive, strictly anaerobic spore forming bacterium, found in soil and aquatic environments as well as in mammalian intestinal tracts. C. difficile is one of the major pathogenic clostridia. This bacterium has become a key public health issue associated with antibiotic therapy in industrialized countries. C. difficile-associated diarrhoea is currently the most frequently occurring nosocomial diarrhoea in Europe and worldwide. Since the last decade the number of severe infection forms has been rising due to emergence of the hypervirulent and epidemic strains as ribotype 027 R20291 strain. C. difficile infection causes diarrhoea, colitis and even death. Many aspects of C. difficile pathogenesis remain poorly understood. Particularly, the molecular mechanisms of its adaptation to changing conditions inside the host are to be scrutinized. During the infection cycle C. difficile survives in bacteriophage-rich gut communities possibly by relying on some special systems that control the genetic exchanges favored within these complex environments. During the last decade, CRISPR (clustered regularly interspaced short palindromic repeats)-Cas (CRISPR-associated) systems of adaptive prokaryotic immunity against exogenic genetic elements has become the center of interest among various anti-invader bacterial defense systems.Previous studies revealed the presence of abundant and diverse CRISPR RNAs in C. difficile. C. difficile has an original CRISPR system, which is characterized by the presence of an unusually large set of CRISPR arrays (12 arrays in the laboratory 630 strain and 9 ones in the hypervirulent R20291 strain), of two or three sets of cas genes conserved in the majority of sequenced C. difficile genomes and the prophage location of several CRISPR arrays. However, the role CRISPR-Cas plays in the physiology and infectious cycle of this important pathogen remains obscure.The general aims of this work run as follows: 1) to investigate the role and the functionality of C. difficile CRISPR-Cas system in the interactions with foreign DNA elements (such as plasmids), 2) to reveal the way C. difficile CRISPR-Cas system expression is regulated and functions in different states of bacterial culture, including its response to stresses. In the present PhD thesis the functionality of C. difficile CRISPR-Cas system was investigated (Chapter 2). Through conjugation efficiency assays defensive function (in interference) of C. difficile CRISPR-Cas system was demonstrated. The correlation between the previously known levels of expression of CRISPR RNAs and the observed levels of interference has also been shown. Moreover, through the series of interference experiments the functionality of PAMs (protospacer adjacent motifs) was confirmed, which have already been predicted in silico. Additionally, the general functional PAM consensus was determined using PAM libraries experiments. Furthermore, an adaptive function of C. difficile CRISPR-Cas system was shown for laboratory strain. The role of multiple cas operons in C. difficile CRISPR functionality is also demonstrated in this Chapter.In Chapter 3 the link between C. difficile CRISPR-Cas system and a new type I toxin-antitoxin system is demonstrated, as well as a possible co-regulation under biofilm and stress conditions of CRISPR-Cas system and these toxin-antitoxin modules. This Chapter also defines a possible role of c-di-GMP in regulation of C. difficile CRISPR-Cas system. Additionally, Chapter 4 describes the utilization of endogenous C. difficile CRISPR-Cas system as a novel tool for genome editing in C. difficile. Altogether, the obtained data highlight the original features of active C. difficile CRISPR-Cas system and demonstrate its biotechnological potential
RAMALHETE, Sara de Castro Gonçalves. "Exploring the relationship between toxin and spore prodution in the human enteric pathogen Clostridium difficile." Master's thesis, Instituto de Higiene e Medicina Tropical, 2015. http://hdl.handle.net/10362/19069.
Повний текст джерелаClostridium difficileis currently the major cause of antibiotic-associated gastrointestinal diseases in adults. This is a Gram-positive bacterium, endospore-forming and an obligate anaerobe that colonizes the gastrointestinal tract.Recent years have seen a rise in C. difficile associated disease (CDAD) cases, associated with more severe disease symptoms, higher rates of morbidity, mortality and recurrence, which were mostly caused due to the emergence of “hypervirulent” strains but also due to changing patterns of antibiotics use. C. difficile produces two potent toxins, TcdA and TcdB, which are the main virulence factors and the responsible for the disease symptoms. These are codified from a Pathogenicity Locus (PaLoc), composed also by the positive regulator, TcdR, the holin-like protein, TcdE, and a negative regulator, TcdC. Besides the toxins, the oxygen-resistant spores are also essential for transmission of the organism through diarrhea; moreover, spores can accumulate in the environment or in the host, which will cause disease recurrence.The expression of the PaLoc genes occurs in vegetative cells, at the end of the exponential growth phase, and in sporulating cells. In this work, we constructed two in-frame deletion mutants of tcdR and tcdE. We showed that the positive auto regulation oftcdR is not significant. However, tcdR is always necessary for the expression of the PaLoc genes.A previous work showed that, except tcdC, all the PaLoc genes are expressed in the forespore. Here, we detected TcdA at the spore surface. Furthermore, we showed that the in-frame deletion of tcdE does not affect the accumulation of TcdA in the culture medium or in association with cells or spores. This data was important for us to conclude about the infeccious process: it suggests that the spore may be the vehicle for the delivery of TcdA in early stages of infection, that TcdA may be released during spores germination and that this spore may use the same receptor recognized by TcdA to bind to the colonic mucosa.
Clark, Andrew Elton, and Andrew Elton Clark. "The Clostridium difficile Flagellar System Mediates Toxin Synthesis, Pathogenicity, and Activation of Innate Immune Responses." Diss., The University of Arizona, 2016. http://hdl.handle.net/10150/623153.
Повний текст джерелаGIRY, MURIELLE. "Les gtpases de la famille rho : cibles intracellulaires des toxines a et b de clostridium difficile." Paris 6, 1995. http://www.theses.fr/1995PA066607.
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