Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0017160 (gastroenteritis)
 11,398 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Toxigenic Escherichia coli of human and animal origin have been classified into three categories: enterotoxigenic E. coli (ETEC), verotoxigenic E. coli (VTEC), and necrotoxigenic E. coli (NTEC), ETEC are a major cause of infant diarrhoea in less-developed countries and frequently cause colibacillosis in domestic animals. Human ETEC strains may synthesize LT-I and/or STa enterotoxins and they may possess the colonization factors CFA/I to CFA/IV; porcine strains synthesize LT-I, STa and/or STb, and possess the colonization antigens K88, P987, K99 or F41; and bovine strains are usually STa producers harbouring on the bacterial surface K99 or F41 colonization factors. There is a high host-specificity, because of that ETEC from animals are not pathogen for humans. VTEC strains may produce three mainly types of verotoxins (VT1, VT2, VT2vp1) that are functionally and structurally related to the shiga toxin. The VTEC of human and bovine origins produce VT1, VT2 or both, whereas VT2vp1 is elaborated by E. coli that cause edema disease in swine. The VTEC strains belonging mainly to serotypes O157:H7 or H-, O26:H11 and O111:H-, are now considered to be the major cause of two human syndromes of hitherto unknown cause: hemorrhagic colitis and hemolytic uremic syndrome. Most outbreaks of VTEC infection occurred in USA, Canada and United Kingdom during the last ten years and have been linked to consumption of undercooked ground beef, and, to a lesser extent, to the drinking of unpasteurized milk. Thus, the principal reservoir of VTEC is the intestinal tract of cattle. By contrast, it is presumed that human beings are the major reservoir of ETEC, and that contaminated water is a principal vehicle for transmission of ETEC infections. NTEC strains are able to elaborate two types of cytotoxic necrotizing factors (CNF1 and CNF2). Strains of human origin usually produce CNF1, whereas bovine NTEC generally synthesize CNF2. NTEC strains are not responsible for food-associated outbreaks of gastroenteritis, but CNF1 and CNF2 are very good markers of the source of food contamination.
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PMID:[Enterotoxigenic, verotoxigenic, and necrotoxigenic Escherichia coli in food and clinical samples. Role of animals as reservoirs of strains pathogenic for humans]. 754 50

The isolation of Shiga toxin-producing Escherichia coli (STEC) other than serogroup O157 from clinical stool samples is problematic due to the lack of differential phenotypic characteristics from non-pathogenic E. coli. The development of molecular reagents capable of identifying both toxin and serogroup-specific genetic determinants holds promise for a more comprehensive characterization of stool samples and isolation of STEC strains. In this study, 876 stool samples from paediatric patients with gastroenteritis were screened for STEC using a cytotoxicity assay, commercial immunoassay and a conventional PCR targeting Shiga-toxin determinants. In addition, routine culture methods for isolating O157 STEC were also performed. The screening assays identified 45 stools presumptively containing STEC, and using non-differential culture techniques a total of 20 O157 and 22 non-O157 strains were isolated. These included STEC serotypes O157 : H7, O26 : H11, O121 : H19, O26 : NM, O103 : H2, O111 : NM, O115 : H18, O121 : NM, O145 : NM, O177 : NM and O5 : NM. Notably, multiple STEC serotypes were isolated from two clinical stool samples (yielding O157 : H7 and O26 : H11, or O157 : H7 and O103 : H2 isolates). These data were compared to molecular serogroup profiles determined directly from the stool enrichment cultures using a LUX real-time PCR assay targeting the O157 fimbrial gene lpfA, a microsphere suspension array targeting allelic variants of espZ and a gnd-based molecular O-antigen serogrouping method. The genetic profile of individual stool cultures indicated that the espZ microsphere array and lpfA real-time PCR assay could accurately predict the presence and provide preliminary typing for the STEC strains present in clinical samples. The gnd-based molecular serogrouping method provided additional corroborative evidence of serogroup identities. This toolbox of molecular methods provided robust detection capabilities for STEC in clinical stool samples, including co-infection of multiple serogroups.
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PMID:Isolation and detection of Shiga toxin-producing Escherichia coli in clinical stool samples using conventional and molecular methods. 1950 73

Shiga-toxigenic Escherichia coli (STEC) is an important cause of diarrheal disease. The most notorious STEC serotype is O157:H7, which is associated with hemorrhagic colitis and hemolytic-uremic syndrome (HUS). As a result, this serotype is routinely screened for in clinical microbiology laboratories. With the bias toward the identification of the O157 serogroup in routine diagnostic processes, non-O157 STEC has been largely underrepresented in the epidemiology of STEC infections. This diagnostic bias is further complicated by the fact that many non-O157 STEC infections cause nonspecific gastroenteritis symptoms reminiscent of enteric viral infections. In this study, real-time PCR was used to amplify Shiga toxin genetic determinants (stx(1) and stx(2)) from enriched stool samples that were initially submitted for the testing of enteric viruses in patients with suspected viral gastroenteritis between May and September of 2006, 2007, and 2008 (n = 2,702). Samples were submitted from the province of Alberta, Yukon, the Northwest Territories, and Nunavut, Canada. A total of 38 samples (1.4%) tested positive for Shiga toxin genes, and 15 isolates were cultured for further characterization. Several of the serotypes identified (O157:H7, O26:HNM, O26:H11, O103:H25, O121:H19, and O145:HNM) have been previously associated with outbreaks and HUS. This study outlines the importance of combining molecular methods with classical culture techniques to enhance the detection of emerging non-O157 as well as O157 serotypes in diarrheal stool samples. Furthermore, atypical diarrhea disease caused by non-O157 STEC can be routinely missed due to screening only for viral agents.
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PMID:Shiga-toxigenic Escherichia coli detection in stool samples screened for viral gastroenteritis in Alberta, Canada. 2114 49

Enterohemorrhagic Escherichia coli (EHEC; E. coli) are food-borne agents associated with gastroenteritis, enterocolitis, bloody diarrhea and the hemolytic-uremic syndrome (HUS). Bovine milk glycans have been shown to contain oligosaccharides which are similar to host epithelial cell receptors and can therefore prevent bacterial adhesion. This study aimed to describe interactions between EHEC O157:H7 EDL933 and O26:H11 21765 and milk fat globules (MFGs) in raw milk and raw milk cheese, and the impact of MFGs on EHEC strains adhesion to the intestinal tract in vitro and in vivo. Both EHEC serotypes clearly associated with native bovine MFGs and significantly limited their adhesion to a co-culture of intestinal cells. The presence of MFGs in raw milk cheese had two effects on the adhesion of both EHEC serotypes to the intestinal tracts of streptomycin-treated mice. First, it delayed and reduced EHEC excretion in mouse feces for both strains. Second, the prime implantation site for both EHEC strains was 6 cm more proximal in the intestinal tracts of mice fed with contaminated cheese containing less than 5% of fat than in those fed with contaminated cheese containing 40% of fat. Feeding mice with 40% fat cheese reduced the intestinal surface contaminated with EHEC and may therefore decrease severity of illness.
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PMID:Milk Fat Globules Hamper Adhesion of Enterohemorrhagic Escherichia coli to Enterocytes: In Vitro and in Vivo Evidence. 2986 55