Colonization Factors of Enterotoxigenic Escherichia coli

Madhavan, T.; Sakellaris, Harry

doi:10.1016/bs.aambs.2014.09.003

Cited by 86 publications

(114 citation statements)

References 149 publications

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“…In order to deliver these toxins to the small intestinal epithelium, ETEC need to attach to epithelial cells, which they achieve by means of specific colonisation factors (Qadri et al, 2005; Madhavan and Sakellaris, 2015). These factors are highly variable structurally and antigenically, and also differ between isolates from humans and animals.…”

Section: Dec Pathotypesmentioning

confidence: 99%

Are Escherichia coli Pathotypes Still Relevant in the Era of Whole-Genome Sequencing?

Robins-Browne

Holt

Ingle³

et al. 2016

Front. Cell. Infect. Microbiol.

131

120

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The empirical and pragmatic nature of diagnostic microbiology has given rise to several different schemes to subtype E.coli, including biotyping, serotyping, and pathotyping. These schemes have proved invaluable in identifying and tracking outbreaks, and for prognostication in individual cases of infection, but they are imprecise and potentially misleading due to the malleability and continuous evolution of E. coli. Whole genome sequencing can be used to accurately determine E. coli subtypes that are based on allelic variation or differences in gene content, such as serotyping and pathotyping. Whole genome sequencing also provides information about single nucleotide polymorphisms in the core genome of E. coli, which form the basis of sequence typing, and is more reliable than other systems for tracking the evolution and spread of individual strains. A typing scheme for E. coli based on genome sequences that includes elements of both the core and accessory genomes, should reduce typing anomalies and promote understanding of how different varieties of E. coli spread and cause disease. Such a scheme could also define pathotypes more precisely than current methods.

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Section: Dec Pathotypesmentioning

confidence: 99%

Are Escherichia coli Pathotypes Still Relevant in the Era of Whole-Genome Sequencing?

Robins-Browne

Holt

Ingle³

et al. 2016

Front. Cell. Infect. Microbiol.

131

120

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“…Probiotics may interfere with pathogen invasion by reducing or inhibiting pathogen adherence, producing antimicrobials, or interfering with toxins (41). Indeed, some pathogens, such as C. difficile, B. cereus, Vibrio cholerae, and Escherichia coli, may secrete toxins that are implicated in bacterial virulence (11,(42)(43)(44). Proteins secreted and released into the environment might mediate some of the positive effects observed in probiotics (45,46).…”

Section: Discussionmentioning

confidence: 99%

“…Equally, many other pathogens, such as Salmonella species, Escherichia coli, Shigella spp., Staphylococcus aureus, and Bacillus cereus, produce several toxins that target intestinal mucosa (10)(11)(12). B. cereus, a spore-forming Gram-positive bacterium, is an opportunistic pathogen that is ubiquitous in the environment.…”

mentioning

confidence: 99%

Secreted Compounds of the Probiotic Bacillus clausii Strain O/C Inhibit the Cytotoxic Effects Induced by Clostridium difficile and Bacillus cereus Toxins

Ripert

Racedo

Elie

et al. 2016

Antimicrob Agents Chemother

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Although the use of probiotics based on Bacillus strains to fight off intestinal pathogens and antibiotic-associated diarrhea is widespread, the mechanisms involved in producing their beneficial effects remain unclear. Here, we studied the ability of compounds secreted by the probiotic Bacillus clausii strain O/C to counteract the cytotoxic effects induced by toxins of two pathogens, Clostridium difficile and Bacillus cereus, by evaluating eukaryotic cell viability and expression of selected genes. Coincubation of C. difficile and B. cereus toxic culture supernatants with the B. clausii supernatant completely prevented the damage induced by toxins in Vero and Caco-2 cells. The hemolytic effect of B. cereus was also avoided by the probiotic supernatant. Moreover, in these cells, the expression of rhoB, encoding a Rho GTPase target for C. difficile toxins, was normalized when C. difficile supernatant was pretreated using the B. clausii supernatant. All of the beneficial effects observed with the probiotic were abolished by the serine protease inhibitor phenylmethylsulfonyl fluoride (PMSF). Suspecting the involvement of a secreted protease in this protective effect, a protease was purified from the B. clausii supernatant and identified as a serine protease (M-protease; GenBank accession number Q99405). Experiments on Vero cells demonstrated the antitoxic activity of the purified protease against pathogen supernatants. This is the first report showing the capacity of a protease secreted by probiotic bacteria to inhibit the cytotoxic effects of toxinogenic C. difficile and B. cereus strains. This extracellular compound could be responsible, at least in part, for the protective effects observed for this human probiotic in antibiotic-associated diarrhea.T he gut, one of the biggest surfaces of exchange between the body's internal and external environment, is in permanent contact with antigens. Indeed, the intestinal barrier constitutes an important playground for numerous intestinal pathogen bacteria and toxins.Among them, Clostridium difficile, an anaerobic Gram-positive bacterium, is a major cause of diarrhea, pseudomembranous colitis, and septicemia, and it can lead to death. Hospital stay and use of antibiotics are major risk factors for contracting this disease (1). Over the past decade, the frequency and severity of C. difficile infections have increased markedly due to the emergence of socalled hypervirulent strains that overproduce toxins (2-4). The C. difficile toxins modify target cell proteins to cause disassembly of the actin cytoskeleton and induce severe inflammation (5).Expression of several host genes, mainly those involved in cellular processes, cell-cell interactions, apoptosis, and inflammation, is modified during C. difficile infection (6). These include host genes encoding RhoB (regulating actin cytoskeleton and interactions between cells), ZO-1 (tight-junction protein), and ROCK2 (actin cytoskeleton and signaling protein regulator) (7-9).Equally, many other pathogens, such as Salmonella species, E...

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“…As cepas enterotoxigênicas, além da capacidade de produzirem toxinas, precisam aderir-se à mucosa do intestino delgado e colonizá-lo para que o processo infeccioso se estabeleça. Esta adesão é mediada por fímbrias protéicas, que são conhecidas como fatores de colonização presentes na superfície bacteriana e que reconhecem receptores específicos, localizados na superfície da célula epitelial intestinal (MADHAVAN; SAKELLARIS, 2015). No patotipo ETEC são conhecidos vários fatores de colonização como: K88 (F4), K99 (F5), 987P e F41 isolados de cepas de ETEC de animais (suínos, bovinos e ovinos) (ZHOU; ZHU; ZHU, 2012) e os fatores de colonização (CFAs) descritos em cepas enterotoxigênicas isoladas de humanos.…”

Section: Introductionunclassified

Caracterização genotípica de fatores de virulência de Escherichia Coli enterotoxigênica isoladas de água para consumo humano

Cestari

Schuroff

Lima

et al. 2016

cmbio

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ResumoIntrodução: As doenças veiculadas pela água são principalmente causadas por patógenos entéricos, sendo o patotipo Escherichia coli enterotoxigênica (ETEC) de grande importância em países em desenvolvimento. Objetivo: Detectar a presença de genes de virulência relacionados à ETEC em cepas de E. coli isoladas de água para consumo humano. Metodologia: 295 cepas de E. coli obtidas de água de 27 municípios do norte do Estado do Paraná, Brasil, entre fevereiro e dezembro de 2005, foram testadas quanto a presença de genes que codificam para as enterotoxinas LT-I (lt-I), ST-a (st-a) e ST-b (st-b) e para os fatores de colonização CFA/I (cfa/I), CFA/II (cfa/ II), K88 (faeG) e K99 (fanC) através da técnica da PCR. Resultados: Das 295 cepas de E. coli estudadas, 36 (12,2%) apresentaram o gene lt-I, uma (0,34%) o gene st-a e três (1,02%) o st-b. Quanto aos fatores de colonização, três cepas (1,02%) foram positivas para o gene faeG, quatro (1,36%) para cfa/I, duas (0,68%) para cfa/II e nenhuma apresentou o gene fanC. Uma cepa (0,34%) foi positiva simultaneamente para os genes lt-I e st-b e outra (0,34%) para os genes lt-I e faeG. Conclusão: Logo, cinquenta e uma (17,29%) cepas apresentaram, pelo menos, um gene que codifica enterotoxina e/ou fator de colonização relacionado à ETEC. Sendo assim, o cuidado com a qualidade microbiológica da água para consumo humano é fundamental, evitando que a mesma torne-se veículo de transmissão de bactérias potencialmente patogênicas, como ETEC. Palavras-chave: ETEC. Água Potável. Fatores de Virulência. LT-I (lt-I), ST-a (st-a) and ST-b (st-b) Abstract

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Colonization Factors of Enterotoxigenic Escherichia coli

Cited by 86 publications

References 149 publications

Are Escherichia coli Pathotypes Still Relevant in the Era of Whole-Genome Sequencing?

Are Escherichia coli Pathotypes Still Relevant in the Era of Whole-Genome Sequencing?

Secreted Compounds of the Probiotic Bacillus clausii Strain O/C Inhibit the Cytotoxic Effects Induced by Clostridium difficile and Bacillus cereus Toxins

Caracterização genotípica de fatores de virulência de Escherichia Coli enterotoxigênica isoladas de água para consumo humano

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