Academic literature on the topic 'Produkce enterotoxinu'
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Journal articles on the topic "Produkce enterotoxinu"
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LOPES, HELENA RODRIGUES, ALBA LUCIA SOLINO NOLETO, MARC DIAZ de LAS HERAS, and MERLIN S. BERGDOLL. "Selective Enterotoxin Production in Foods by Staphylococcus aureus Strains That Produce More Than One Enterotoxin." Journal of Food Protection 56, no. 6 (June 1, 1993): 538–40. http://dx.doi.org/10.4315/0362-028x-56.6.538.
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Staphylococcus aureus strain S-6, producer of enterotoxins A and B; strain FRI-913, producer of enterotoxins A, C, and E; and strain FRI-196E, producer of enterotoxins A and D, were grown in milk (pH 6.8), potato salad with mayonnaise, and boiled egg white (pH 8.0–8.5). Enterotoxins were detectable in milk incubated at 26°C when colony counts were less than 106. Enterotoxin production by strain S-6 was detectable in potato salad at 106 CFU at both 26 and 37°C. Enterotoxin A production by strain FRI-913 was detectable at approximately 106 CFU/g, whereas enterotoxin C was detectable only when growth reached approximately 108 CFU/g. Production of enterotoxins A and D by strain FRI-196E was detectable when growth was greater than 107 CFU/g. Production of enterotoxins A and B by strain S-6 in boiled egg white was detectable at greater than 106 CFU/g. In most experiments, enterotoxins A and C from strain FRI-913 were detectable when cell counts were greater than 107 CFU/g, whereas enterotoxin A and enterotoxin D production by strain FRI-196E was detectable at counts between 105 and 106 CFU/g. It can be concluded that enterotoxin production is influenced by the time of incubation and the composition and pH of the food.
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Chopra, A. K., and C. W. Houston. "Purification and partial characterization of a cytotonic enterotoxin produced by Aeromonas hydrophila." Canadian Journal of Microbiology 35, no. 7 (July 1, 1989): 719–27. http://dx.doi.org/10.1139/m89-117.
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This report describes the purification and partial characterization of a cytotonic enterotoxin produced by a human diarrheal isolate (SSU) of Aeromonas hydrophila. The extracellular enterotoxin was purified by (NH4)2SO4 precipitation, hydrophobic column chromatography, and chromatofocusing. The highly purified enterotoxin exhibited a molecular mass of 44 kDa and an isoelectric point in the range of 4.3–5.5 as determined by chromatofocusing. Western blot analysis using Aeromonas anti-enterotoxin revealed a single band at 44 kDa; however, cholera antitoxin failed to detect the enterotoxin antigen. This non-cholera toxin cross-reactive (non-CTC) enterotoxin was biologically active in vivo as determined by rabbit ligated ileal loop and rabbit skin vascular permeability assays. Biological activity also was expressed in vitro by this toxin as measured by the elongation of Chinese hamster ovary (CHO) cells. The enterotoxic activity associated with this molecule was neutralized completely by homologous antibodies but not by cholera antitoxin. The purified toxin preparation was free of hemolytic and cytotoxic activities as determined by its inability to lyse rabbit red blood cells or damage CHO cells, respectively. Furthermore, this toxin induced the elevation of cAMP in CHO cells suggesting thereby that the mechanism of action of Aeromonas non-CTC enterotoxin may be similar to heat-labile enterotoxins of Escherichia coli and Vibrio cholerae.Key words: Aeromonas hydrophila, cytotonic enterotoxin, cholera toxin, cAMP
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CENCI-GOGA, B. T., M. KARAMA, P. V. ROSSITTO, R. A. MORGANTE, and J. S. CULLOR. "Enterotoxin Production by Staphylococcus aureus Isolated from Mastitic Cows." Journal of Food Protection 66, no. 9 (September 1, 2003): 1693–96. http://dx.doi.org/10.4315/0362-028x-66.9.1693.
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Staphylococcus aureus is an important cause of mastitis in cows. The ability of S. aureus strains to produce one or more enterotoxins in milk and dairy products is linked to staphylococcal food poisoning. To determine whether staphylococci causing bovine mastitis could cause human foodborne intoxication, the production of staphylococcal enterotoxins A through D (SEA, SEB, SEC, and SED) by 160 S. aureus isolates was evaluated with the use of a reverse passive latex agglutination enterotoxin kit. All S. aureus strains were isolated over a 9-month period from 2,343 routine submissions of a composite quarter collection of individual mastitic cows at 18 dairy farms in the San Joaquin Valley in California. Prior to enterotoxin detection, isolates were grown by a method that enhances the in vitro synthesis of enterotoxin. Twenty-two of 160 S. aureus isolates produced enterotoxin. Seven produced SEC, 12 produced SED, and 3 produced both SEC and SED. None of the isolates produced SEA or SEB.
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Valihrach, L., K. Demnerová, R. Karpíšková, and I. Melenová. "The expression of selected genes encoding enterotoxins in Staphylococcus aureus strains." Czech Journal of Food Sciences 27, Special Issue 2 (January 3, 2010): 56–65. http://dx.doi.org/10.17221/208/2009-cjfs.
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Staphylococcus aureus is an important food-borne pathogen, which produces many toxic substances that cause a variety of illnesses. Some strains of S. aureus produce thermostable enterotoxins that can be responsible for alimentary intoxication. The aim of this work was to establish a protocol for the study of 9 enterotoxin genes expression (sea-sej). First, a method for the detection of genes encoding enterotoxins was established and then a method for the determination of the expression of these genes was optimised, using a range of the PCR techniques (multiplex, touchdown and real-time). The expression of staphylococcal enterotoxin genes was evaluated both qualitatively and quantitatively. In present study were used S. aureus strains from culture collections as well as those newly-isolated from raw milk samples. The obtained results indicate the various expression of the different genes for enterotoxin. However the main benefit of this work is the established protocol for the study of enterotoxin gene expression, which can provide a better understanding of the conditions for the enterotoxins production.
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Thomas, Damien, Olivier Dauwalder, Virginie Brun, Cedric Badiou, Tristan Ferry, Jerome Etienne, François Vandenesch, and Gerard Lina. "Staphylococcus aureus Superantigens Elicit Redundant and Extensive Human Vβ Patterns." Infection and Immunity 77, no. 5 (March 2, 2009): 2043–50. http://dx.doi.org/10.1128/iai.01388-08.
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ABSTRACT Staphylococcus aureus can produce a wide variety of exotoxins, including toxic shock syndrome toxin 1 (TSST-1), staphylococcal enterotoxins, and staphylococcal enterotoxin-like toxins. These toxins share superantigenic activity. To investigate the β chain (Vβ) specificities of each of these toxins, TSST-1 and all known S. aureus enterotoxins and enterotoxin-like toxins were produced as recombinant proteins and tested for their ability to induce the selective in vitro expansion of human T cells bearing particular Vβ T-cell receptors (TCR). Although redundancies were observed between the toxins and the Vβ populations, each toxin induced the expansion of distinct Vβ subsets, including enterotoxin H and enterotoxin-like toxin J. Surprisingly, the Vβ signatures were not associated with a specific phylogenic group of toxins. Interestingly, each human Vβ analyzed in this study was stimulated by at least one staphylococcal superantigen, suggesting that the bacterium derives a selective advantage from targeting the entire human TCR Vβ panel.
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Radoslava, Savić Radovanović, Zdravković Nemanja, and Velebit Branko. "Occurrence and Characterization of Enterotoxigenic Staphylococci Isolated from Soft Cheeses in Serbia." Acta Veterinaria 70, no. 2 (June 1, 2020): 238–54. http://dx.doi.org/10.2478/acve-2020-0017.
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AbstractA total of 415 cheese samples produced with raw or cooked milk collected from local markets were analysed for the presence of coagulase-positive staphylococci. In 85 (20.48%) samples the presence of coagulase positive staphylococci was detected. The ELFA technique VIDAS SET2 (BioMerieux, France) was used for testing coagulase-positive staphylococci strains to produce classical enterotoxins (SEA, SEB, SEC, SED, SEE), and to determine the enterotoxins in cheese samples. The number of coagulase-positive staphylococci in cheese samples ranged from 1-5.79 log CFU g-1. Out of 85 coagulase-positive strains 26 (30.59%) produced enterotoxins. The presence of genes for the synthesis of staphylococcal enterotoxins (SE) in the obtained extracts of DNA from 26 enterotoxigenic strains was detected by conventional multiplex PCR technique (for genes sea and seb) i.e. the Real-Time PCR technique for genes sec, sed and see. In all 26 strains of coagulase-positive staphylococci (originating from cheeses produced from raw or cooked milk, which were enterotoxin producers) sea was present, and in 24 strains in addition to sea gene, seb was detected. None of the isolates possessed genes for the synthesis of enterotoxin C (SEC), D (SED) and E (SEE). Out of 26 tested cheese samples positive for enterotoxigenic coagulase-positive staphylococci, enterotoxin was detected in 2 (7.69%) samples of sweet-coagulating cheese, in which the number of enterotoxigenic coagulase-positive staphylococci exceeded 5 log CFU g-1. In sweet-coagulating cheeses in which the number of coagulase-positive staphylococci exceeds 5 log CFU g-1 and the pH value was higher than 5.0, enterotoxins may be present in amounts sufficient to cause intoxication.
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Al Bustan, M. A., E. E. Udo, and T. D. Chugh. "Nasal carriage of enterotoxin-producingStaphylococcus aureusamong restaurant workers in Kuwait City." Epidemiology and Infection 116, no. 3 (June 1996): 319–22. http://dx.doi.org/10.1017/s0950268800052638.
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SUMMARYEnterotoxin-producingStaphylococcus aureusis a common cause of staphylococcal food poisoning. To determine the incidence of carriage of enterotoxin-producingS. aureusin a sample of the healthy population in Kuwait city, restaurant workers in the city were screened for nasal carriage ofS. aureus. 26·6% of 500 workers studied carriedS. aureusand 86·6% of theS. aureusproduced staphylococcal enterotoxins. 28 % produced enterotoxin A, 28·5 % produced enterotoxin B, 16·4% produced enterotoxin C and 3·5% produced enterotoxin D. Ten isolates produced both enterotoxins A and B or A and C. 73 % of the isolates were untypeable with standard phages. However, 17·1%, 3% and 6% belonged to phage groups I, II and III respectively. The results demonstrated a high level of enterotoxigenicS. aureuscarriage among restaurant workers which although lower than that reported for the general population and hospital workers may be important in the restaurant industry.
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Melconian, A. K., J. Fleurette, and Y. Brun. "Studies on staphylococci from toxic shock syndrome in France, 1981–1983." Journal of Hygiene 94, no. 1 (February 1985): 23–29. http://dx.doi.org/10.1017/s002217240006109x.
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SUMMARYStaphylococci from 22 cases of toxic shock syndrome with onsets between 1981 and March 1983 have been studied. Another four cases were detected by abstract surveillance. Three of these patients died. The case histories show that the syndrome occurs in women during menstruation as well as in males and in children, and is associated withStaphylococcus aureusinfections.The production of enterotoxins (A, B, C) and toxic shock toxin byS. aureusisolates from toxic shock syndrome was investigated. Twenty-two of the 23 isolates were found to be toxigenie: 7 produced enterotoxin A, 8 produced enterotoxin B, 3 produced enterotoxin C and 13 produced toxic shock toxin. The latter was found with enterotoxin A in five cases, and with enterotoxins A and B in only one case.Sixty-three percent of 40S. aureusstrains isolated from the vagina of patients with diseases other than toxic shock syndrome produced toxin; eight of these strains produced toxic shock toxin.
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KIM, JUNG-BEOM, JAI-MOUNG KIM, SO-YEONG KIM, JONG-HYUN KIM, YONG-BAE PARK, NA-JUNG CHOI, and DEOG-HWAN OH. "Comparison of Enterotoxin Production and Phenotypic Characteristics between Emetic and Enterotoxic Bacillus cereus." Journal of Food Protection 73, no. 7 (July 1, 2010): 1219–24. http://dx.doi.org/10.4315/0362-028x-73.7.1219.
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Bacillus cereus was divided into emetic toxin (cereulide)– and enterotoxin-producing strains, but emetic toxin–producing B. cereus is difficult to detect immunochemically. Screening methods for emetic toxin–producing B. cereus are needed. The objectives of this study were to identify and detect emetic toxin–producing B. cereus among 160 B. cereus strains, and to compare enterotoxin production and phenotypic characteristics between the emetic toxin–producing and enterotoxin-producing strains. Forty emetic toxin–producing B. cereus strains were determined with high-pressure liquid chromatography–mass spectrometry analysis. Among the emetic toxin–producing strains (n = 40), 31 (77.5%) and 3 (7.5%) strains produced nonhemolytic enterotoxin (NHE) and hemolysin BL (HBL) enterotoxins, respectively. In addition, 107 (89.2%) and 100 (83.3%) strains produced NHE and HBL enterotoxins among the enterotoxin-producing strains (n = 120). The number of strains positive for starch hydrolysis, salicin fermentation, and hemolysis among the emetic toxin–producing strains were 3 (7.5%), 3 (7.5%), and 26 (65.0%), respectively, and among enterotoxin-producing strains, these numbers were 101 (84.2%), 100 (83.3%), and 111 (92.5%), respectively. In particular, the three emetic toxin–producing B. cereus strains (JNHE 6, JNHE 36, and KNIH 28) produced the HBL and NHE enterotoxins and were capable of starch hydrolysis and salicin fermentation. The absence of HBL enterotoxin and certain phenotypic properties, such as starch hydrolysis and salicin fermentation, indicates that these properties were not critical characteristics of the emetic toxin–producing B. cereus tested in this study.
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MANTIS (Α.Ι. ΜΑΝΤΗΣ), A. J., and D. K. PAPAGEORGIOU (Δ.Κ. ΠΑΠΑΓΕΩΡΓΙΟΥ). "Conditions of staphylococcal enterotoxin production in milk and milk products." Journal of the Hellenic Veterinary Medical Society 54, no. 3 (December 19, 2017): 242. http://dx.doi.org/10.12681/jhvms.15267.
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The authors reviewed the existing scientific data, concerning the ability of Staphylococcus aureus to grow and produce enterotoxins in milk and in dairy products particularly in cheeses. S. aureus can grow well in liquid raw or pasteurized milks and produce enterotoxins if the product is stored in favorable for the pathogen temperature. Cream also supports growth of S. aureus and enterotoxin production, but butter as well as fermented products like yogurt and buttermilk are not favorable substrates for the production of enterotoxins. Cheeses represent a complex environment, due to their great variety in processing technology and environment. Fresh cheeses, soft cheeses and semi-hard and hard cheeses can support growth of S. aureus during the first stages of production up to 48 hours. Normally, the pathogen, if it is present in the milk, will multiply for 3-4 logs and after that, when acidity develops, the populations of S. aureus decrease and usually disappear by the end of the ripening period. However, if enterotoxins are produced during the multiplication phase of the pathogen, it will remain active in the cheese for a long time. Internal mould ripened cheeses (e.g. blue cheese), pasta filata cheeses or the processed cheeses do not represent favorable substrates for the multiplication of S. aureus and enterotoxin production. On the contrary, whey cheeses form a very favorable environment for the enterotoxins' production, because of their high pH and the absence of antagonistic bacterial flora.
Dissertations / Theses on the topic "Produkce enterotoxinu"
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Hrušková, Vendula. "Staphylococcus aureus v potravinách: Identifikace a produkce enterotoxinu v mléce a sýrech." Doctoral thesis, Vysoké učení technické v Brně. Fakulta chemická, 2012. http://www.nusl.cz/ntk/nusl-233361.
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Onemocnění z potravin (alimentární onemocnění) vyvolaná bakteriemi jsou stále aktuálním tématem v celosvětovém měřítku. Abychom zajistili výrobu zdravotně nezávadných potravin, je potřeba nových poznatků o virulenci patogenů, které by doplnily již známé skutečnosti o jejich růstu a přeživání v potravinách. Také potřebujeme vyvíjet rychlé a citlivé metody na detekci těchto patogenů. Dizertační práce popisuje metodu na detekci S. aureus v potravinách, která je založená na PCR v reálném čase ve spojení s namnožením v selektivním médium. Dále pojednává o vlivu environmentálních faktorů na růst S. aureus a tvorbu enterotoxinů v mléce a sýrech. Vyvinuli jsme rychlou a citlivou metodu na detekci S. aureus v potravinách s použitím selektivního namnožení a PCR v reálném čase. Nově vyvinutá metoda umožnila detekci S. aureus na druhý den od přijetí vzorku. Tato metoda může být použita jako rychlejší, citlivějsí a vysoce specifická alternativní metoda ke konvenční mikrobiologické metodě. Zkoumali jsme vliv tří různých teplot, 8°C, 12°C a 20°C na růst S. aureus a tvorbu enterotoxinu D v pasterizovaném mléce a na růst, expresi genu sed a tvorbu enterotoxinu D v tekutém médiu s extraktem z mozku a srdce (BHI). Experimenty byly prováděny v malých skleněných fermentorech po 6 dní. Genová exprese byla sledována pomocí qRT-PCR a tvorba enterotoxinu D byla měřena pomocí imunologické metody ELISA. Růstová křivka v BHI měla stejný průběh při 20°C a 12°C, ale v při 12°C začal růst se spožděním. Při 8°C nebyl pozorován žádný růst. Růst S. aureus v mléce byl ve srovnání s BHI menší. sed mRNA byla detekována při 20°C po 4 hodinách a při 12°C po 7 hodinách a produkce enterotoxinu se objevila v exponenciální fázi růstu. V mléce se produkce SED při 20°C a při 12°C objevila dříve, ale celkové množství vyprodukovaného SED bylo nižší než v BHI. Při 8°C nebyla pozorována žádná produkce SED stejně jako v BHI. Dále byl zkoumán společný vliv nízké teploty 12°C a přítomnosti kompetitivní doprovodné mikroflóry pocházející ze surového mléka na růst S. aureus a produkci enterotoxinu v pasterizovaném mléce. Byl pozorován inhibiční účinek na růst a produkci enterotoxinů a vliv kompetice byl výraznější než vliv nízké teploty. Produkce enterotoxinu byla nízká a odpovídala růstu. Snížením množství doprovodné mikroflóry a zvýšením inokula došlo pouze k nepatrnému zvýšení produkce enterotoxinu. V další fázi byly dva různé typy sýrů zaočkovány S. aureus za účelem simulace sekundární kontaminace při výrobě sýrů. Vzorky byly odebírány v průběhu 4 týdnů. Kritické faktory jako jsou kompetitivní mikrofóra nebo pH, které jsou zodpovědné za regulaci virulence S. aureus byly sledovány. Snažili jsem se rozlišit situace při kterých: (i) není pozorován růst, ale objevuje se produkce enterotoxinu a (ii) dochází k růstu ale bez produkce enterotoxinu.
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Schoeni, Jean L. "Protein and deoxyribonucleic acid heterogeneity in hemolysin BL, a ripartite enterotoxin produced by bacillus cereus." 2002. http://www.library.wisc.edu/databases/connect/dissertations.html.
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Dang, Khanh B. "Detection and quantification of staphylococcus aureus enterotoxin B in food product using isotopic dilution techniques and mass spectrometry." Thèse, 2012. http://hdl.handle.net/1866/9019.
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L’entérotoxine B staphylococcique (SEB) est une toxine entérique hautement résistante à la chaleur et est responsable de plus de 50 % des cas d’intoxication d’origine alimentaire par une entérotoxine. L’objectif principal de ce projet de maîtrise est de développer et valider une méthode basée sur des nouvelles stratégies analytiques permettant la détection et la quantification de SEB dans les matrices alimentaires. Une carte de peptides tryptiques a été produite et 3 peptides tryptiques spécifiques ont été sélectionnés pour servir de peptides témoins à partir des 9 fragments protéolytiques identifiés (couverture de 35 % de la séquence). L’anhydride acétique et la forme deutérée furent utilisés afin de synthétiser des peptides standards marqués avec un isotope léger et lourd. La combinaison de mélanges des deux isotopes à des concentrations molaires différentes fut utilisée afin d’établir la linéarité et les résultats ont démontré que les mesures faites par dilution isotopique combinée au CL-SM/SM respectaient les critères généralement reconnus d’épreuves biologiques avec des valeurs de pente près de 1, des valeurs de R2 supérieure à 0,98 et des coefficients de variation (CV%) inférieurs à 8 %. La précision et l’exactitude de la méthode ont été évaluées à l’aide d’échantillons d’homogénat de viande de poulet dans lesquels SEB a été introduite. SEB a été enrichie à 0,2, 1 et 2 pmol/g. Les résultats analytiques révèlent que la méthode procure une plage d’exactitude de 84,9 à 91,1 %. Dans l’ensemble, les résultats présentés dans ce mémoire démontrent que les méthodes protéomiques peuvent être utilisées efficacement pour détecter et quantifier SEB dans les matrices alimentaires.
Mots clés : spectrométrie de masse; marquage isotopique; protéomique quantitative; entérotoxinesStaphylococcal enterotoxin B is a highly heat-resistant enteric toxin and it is responsible for over 50% of enterotoxin food poisoning. It represents a particular challenge during food processing since, even if the bacteria have been destroyed, the biological activity of the toxin remains unchanged. The objective of this study was to develop and validate a new method based on a novel proteomic strategy to detect and quantify SEB in food matrices. Tryptic peptide map was generated and 3 specific tryptic peptides were selected and used as surrogate peptides from 9 identified proteolytic fragments (sequence coverage of 35%). Peptides were label with light and heavy form of acetic anhydride to create an isobaric tag that will allow quantification. The linearity was tested using mixtures of different molar ratios and the results showed that measurements by LC-MS/MS were within generally accepted criteria for bioassays with slope values near to 1, values of R2 above 0.98 and less than 8% coefficient of variation (%CV). The precision and accuracy of the method were assessed using chicken meat homogenate samples spiked with SEB at 0.2, 1 and 2 pmol/g. The results indicated that the method can provide accuracy within 84.9 – 91.1% range. Overall, the results presented in this thesis show that proteomics-based methods can be effectively used to detect, confirm and quantify SEB in food matrices. Keywords: mass spectrometry; stable isotope labeling; quantitative proteomics; enterotoxins
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Taillon, Christine. "Étude d'un variant de la toxine STb produite par Escherichia coli." Thèse, 2009. http://hdl.handle.net/1866/3712.
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Les E. coli entérotoxinogènes (ETEC) sont souvent la cause de diarrhée post-sevrage chez le porc. Deux types d’entérotoxines sont retrouvées chez les ETEC, soit les thermolabiles, comme la toxine LT, et les thermostables, comme EAST-1, STa et STb. Cette dernière est composée de 48 acides aminés et est impliquée dans la pathologie causée par les ETEC. Pour la première fois un variant de la toxine STb fut découvert dans une étude. Nous avons alors émis l’hypothèse qu’il y a présence de variants dans la population de souches ETEC du Québec. Dans les 100 souches STb+ analysées, 23 possédaient le gène de la toxine avec une variation dans la séquence génétique : l’asparagine était présente en position 12 remplaçant ainsi l’histidine. Une corrélation entre la présence du variant et la présence de facteurs de virulence retrouvés dans ces 100 souches ETEC étudiées a été effectuée. Ce variant semble fortement associé à la toxine STa puisque toutes les souches variantes ont hybridé avec le gène codant pour cette dernière. Étant donné sa présence répandue dans la population de souches ETEC du Québec, nous avons de plus émis l’hypothèse que ce variant a des caractéristiques biologiques altérées par rapport à la toxine sauvage. L’analyse par dichroïsme circulaire a montré que le variant et la toxine sauvage ont une structure secondaire ainsi qu’une stabilité similaires. Par la suite, l’attachement au récepteur de la toxine, le sulfatide, a été étudié par résonnance plasmonique de surface (biacore). Le variant a une affinité au sulfatide légèrement réduite comparativement à la toxine sauvage. Puisque l’internalisation de la toxine fut observée dans une étude précédente et qu’elle semble liée à la toxicité, nous avons comparé l’internalisation du variant et de la toxine sauvage à l’intérieur des cellules IPEC-J2. L’internalisation du variant dans les cellules est légèrement supérieure à l’internalisation de la toxine sauvage. Ces résultats suggèrent que le variant est biochimiquement et structurellement comparable à la toxine sauvage.Enterotoxigenic Escherichia coli (ETEC) are a major cause of post-weaning diarrhea. STb is one of two heat-stable toxins produced by ETEC and is mostly associated with pathogenic porcine isolates. For the first time, a variant of the toxin was observed in a study in 2003. Our hypothesis is that STb variants are present in ETEC strains from Quebec. To screen for alterations at the gene level, a collection of 100 STb+ ETEC strains isolated from diseased pigs was randomly selected and analyzed. A total of 23 strains had a change from His12 to Asn. An association between the presence of the variant and virulence factors present in those strains was done. These strains were also positive for STa. Since this variant seems to be widely distributed in Quebec, we hypothesize that the variant has different biological properties compared to the wild-type STb. First, the secondary structure of the variant and wild-type toxin and their thermal stability was determined by circular dichroism. Both show similar structures and thermal stability. In addition, the binding affinity with the toxin receptor, the sulfatide, was determined by surface plasmon resonance. The affinity of the wild-type for the sulfatide is slightly superior to the variant. Finally, the internalization inside IPEC-J2 cells of the variant was compared to the wild-type. The variant is able to internalize more cells than the wild-type. Altogether, these results suggest that both the variant and the wild-type toxin are biochemically and structurally similar.
Books on the topic "Produkce enterotoxinu"
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Ye, Don D. Y. The detection of enterotoxin produced by Campylobacter jejuni. Ottawa: National Library of Canada, 1993.
Find full textBook chapters on the topic "Produkce enterotoxinu"
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Takeda, Yoshifumi, Shinji Yamasaki, Toshiya Hirayama, and Yasutsugu Shimonishi. "Heat-Stable Enterotoxins Produced by Enteric Bacteria." In Molecular Pathogenesis of Gastrointestinal Infections, 125–38. Boston, MA: Springer US, 1991. http://dx.doi.org/10.1007/978-1-4684-5982-1_17.
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Sato, T., and Y. Shimonishi. "‘Micro domain’ structure of the heat-stable enterotoxin produced by enterotoxigenic Escherichia coli." In Peptides 1994, 547–48. Dordrecht: Springer Netherlands, 1995. http://dx.doi.org/10.1007/978-94-011-1468-4_248.
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THOMPSON, NANCY E., MERLIN S. BERGDOLL, RICHARD F. MEYER, REGINALD W. BENNETT, LLONAS MILLER, and JAMES D. MACMILLAN. "Monoclonal Antibodies to the Enterotoxins and to the Toxic Shock Syndrome Toxin Produced by Staphylococcus aureus." In Monoclonal Antibodies Against Bacteria, 23–59. Elsevier, 1985. http://dx.doi.org/10.1016/b978-0-12-463002-4.50009-4.
Full textConference papers on the topic "Produkce enterotoxinu"
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Al-Asmar, Jawaher, Sara Rashwan, and Layla Kamareddine. "The use of Drosophila Melanogaster as a Model Organism to study the effect of Bacterial Infection on Host Survival and Metabolism." In Qatar University Annual Research Forum & Exhibition. Qatar University Press, 2020. http://dx.doi.org/10.29117/quarfe.2020.0186.
Full textAbstract:
Enterobacteriaceae, a large family of facultative anaerobic bacteria, encloses a broad spectrum of bacterial species including Escherichia coli, Salmonella enterica, and Shigella sonnei, that produce enterotoxins and cause gastrointestinal tract diseases. While much is known about the regulation and function of enterotoxins within the intestine of the host; the lack of cheap, practical, and genetically tractable model organisms has restricted the investigation of others facets of this host-pathogen interaction. Our group, among others, has employed Drosophila melanogaster, as a model organism to shed more light on some aspects of host-pathogen interplays. In this project, we addressed the effect of Escherichia coli, Salmonella enterica, and Shigella sonnei infection on altering the metabolic homeostasis of the host. Drosophila melanogaster flies were orally infected with Escherichia coli, Salmonella enterica, or Shigella sonnei, a method that mimics the natural route used by enteric pathogens to gain access to the gastrointestinal tract in humans. The results of our study revealed that both Escherichia coli and Shigella sonnei pathogens were capable of colonizing the host gut, resulting in a reduction in the life span of the infected host. Escherichia coli and Shigella sonnei infected flies also exhibited altered metabolic profiles including lipid droplets deprivation from their fat body (normal lipid storage organ in flies), irregular accumulation of lipid droplets in their gut, and significant elevation of systemic glucose and triglyceride levels. These metabolic alterations could be mechanistically attributed to the differential down-regulation in the expression of metabolic peptide hormones (Allatostatin A, Diuretic hormone 31, and Tachykinin) detected in the gut of Escherichia coli and Shigella sonnei infected flies. Salmonella enterica; however, was unable to colonize the gut of the host; and therefore, Salmonella enterica infected flies exhibited a relatively normal metabolic status as that of non infected flies. Gaining a proper mechanistic understanding of infection-induced metabolic alterations helps in modulating the pathogenesis of gastrointestinal tract diseases in a host and opens up for promising therapeutic approaches for infection induced metabolic disorders