Summary The bovine gastrointestinal tract is the main reservoir for enterohaemorrhagic Escherichia coli (EHEC) responsible food‐borne infections. Characterization of nutrients that promote carriage these pathogens by ruminant would help to develop ecological strategies reduce their survival in tract. In this study, we show first time free ethanolamine (EA) constitutes a nitrogen source O157:H7 EHEC strain EDL933 intestinal content because induction eut ( e thanolamine ut ilization) gene...

Only a subset of Shiga toxin (Stx)-producing Escherichia coli (STEC) are human pathogens, but the characteristics that account for differences in pathogenicity not well understood. In this study, we investigated distribution stx variants coding Stx2 and its highly virulent STEC seropathotype A low-pathogenic C. We analysed compared transcription corresponding genes, production toxins, stx-phage release basal as induced conditions. found stx(2) variant was mainly associated with strains A,...

ABSTRACT Shiga toxin-producing Escherichia coli (STEC) has been associated with food-borne diseases ranging from uncomplicated diarrhea to hemolytic-uremic syndrome (HUS). While most outbreaks are E. O157:H7, about half of the sporadic cases may be due non-O157:H7 serotypes. To assess pathogenicity STEC isolated dairy foods in France, 40 strains 1,130 raw-milk and cheese samples were compared 15 patients suffering severe disease. The presence genes encoding toxins ( stx 1 , 2 variants),...

The bovine gastrointestinal (GI) tract is the main reservoir for enterohaemorrhagic Escherichia coli (EHEC) responsible food-borne infections. Characterization of nutrients preferentially used by EHEC in intestine would help to develop ecological strategies reduce carriage. However, carbon sources that support growth are poorly documented. In this study, a very low concentration glucose, most abundant monomer included cattle dietary polysaccharides, was detected small contents (BSIC)...

ABSTRACT At least 11 Stx2 variants produced by Shiga toxin-producing Escherichia coli (STEC) isolated from patients and animals have been described. The subtyping of STEC healthy cows positive for stx 2 ( n = 104) or 1 63) was investigated. Stx2vh-b, (renamed Stx2-EDL933), Stx2vh-a were the subtypes mostly detected among bovine isolates (39.5, 39, 25.5%, respectively). Stx2e not present, included in Stx2d group (Stx2d-OX3a, Stx2d-O111, Stx2d-Ount) found infrequently examined (8.5%). A...

ABSTRACT The distribution of virulent factors (VFs) in 287 Shiga toxin-producing Escherichia coli (STEC) strains that were classified according to Karmali et al. into five seropathotypes (M. A. Karmali, M. Mascarenhas, S. Shen, K. Ziebell, Johnson, R. Reid-Smith, J. Isaac-Renton, C. Clark, Rahn, and B. Kaper, Clin. Microbiol. 41:4930-4940, 2003) was investigated. associations VFs with phylogenetic background assessed among the comparison different seropathotypes. analysis showed STEC...

Fifty-six CNF1-producing Escherichia coli strains isolated from cattle with diarrhea or septicemia were screened by PCR for the detection of pap, sfa, afa, clpG, f17 adherence factor and EAST 1 toxin genes. All isolates pap-positive, in accordance close association CNF1 α-hemolysin genes observed on human porcine E. coli. Only gene encoding P adhesin class III (PrsG) was detected. Genes CS31A antigen (71%) S fimbriae (34%) (but not Afa F17) detected among bovine isolates. producing both...

The F17-related adhesins are prevalent in Escherichia coli strains isolated from calves with diarrhea or septicemia and lambs nephropathy. F17 family includes the F17a, F17b, F17c, F111 fimbriae produced by bovine E. G agglutinin human uropathogenic strains. An easy inexpensive multiplex PCR method was developed to detect all identify four subtypes of structural subunit genes two distinct subfamilies adhesin only runs amplification. A strict correlation observed between phenotypic assays...

ABSTRACT A detailed analysis of the molecular epidemiology non-O157:H7 Shiga toxin-producing Escherichia coli (STEC) was performed by using isolates from sporadic cases hemolytic-uremic syndrome (HUS), animal reservoirs, and food products. The belonged to O91 OX3 serogroups were collected in same geographical area over a short period time. Five typing methods used; some these used explore potentially mobile elements like stx genes or plasmids ( 2 -restriction fragment length polymorphism...

Enterohaemorrhagic Escherichia coli (EHEC) are responsible for outbreaks of food- and water-borne illness. The bovine gastrointestinal tract (GIT) is thought to be the principle reservoir EHEC. Knowledge nutrients essential EHEC growth survival in intestine may help developing strategies limit their shedding faeces thus reducing risk human illnesses. To identify specific metabolic pathways induced animal GIT, transcriptome profiles O157:H7 EDL933 during incubation small contents (BSIC)...

We previously described a CS31A-related protein, CF29K, expressed by Klebsiella pneumoniae strains involved in nosocomial infections. In this study, we cloned and sequenced cf29A, the structural gene of CF29K showed that is an antigenic subtype CS31A. The protein was found to be identical CS31A-L on basis biochemical immunological properties. contrast, CS31A-H presented different apparent molecular mass during sodium dodecyl sulfate-polyacrylamide gel electrophoresis, limited degradation...

Healthy cattle are the primary reservoir for O157:H7 Shiga toxin-producing E. coli responsible human food-borne infections. Because farm environment acts as a source of contamination, it is important to better understand factors controlling persistence outside bovine gut. The strain MC2, identified persistent in French farms, possessed characteristics required cause infections and genetic markers associated with clinical isolates. Therefore, capacity MC2 survive during its transit through...

Bovine septicemic Escherichia coli 31A agglutinates bovine, rabbit, and human erythrocytes adheres in vitro to the brush border of bovine or ovine intestinal epithelial cells colon carcinoma Caco-2 cell line. The adhesion hemagglutination E. are mediated by a chromosome-encoded fimbrial adhesin serologically distinct from known adhesins found enterotoxigenic strains. By electron microscopy studies fimbriae designated 20K were observed as fine flexible filaments (diameter, 3 nm) purified...

ABSTRACT Of 220 Shiga toxin-producing Escherichia coli (STEC) strains collected in central France from healthy cattle, food samples, and asymptomatic children, 12 possessed the eae gene included locus of enterocyte effacement (LEE) pathogenicity island. Based on typing, we observed 7 different espA espB tir pathotypes among STEC described new βv variant. As previously observed, O157 serogroup is associated with γ, O26 β, O103 ε. However, unexpected ζ allele was detected 5 isolates. PCR...

The bovine gastrointestinal tract (GIT) is the main reservoir for enterohaemorrhagic Escherichia coli (EHEC) responsible food-borne infections. Therefore, it crucial to develop strategies, such as EHEC suppression by antagonistic microorganisms, reduce survival in GIT of cattle and limit shedding food contamination. Most human-derived Lactobacillus reuteri strains produce hydroxypropionaldehyde (HPA), an antimicrobial compound, during anaerobic reduction glycerol. capacity L. LB1-7, a strain...

The cattle gastrointestinal tract (GIT) is the main enterohemorrhagic Escherichia coli (EHEC) reservoir. In order to identify nutrients required for survival or multiplication of EHEC in bovine GIT, we compared transcriptomes O157:H7 reference strain EDL933 cultured vitro digestive contents (DCs) (rumen, small intestine and rectum) using RNA-sequencing.Gene expression profiles showed that activated common but also specific metabolic pathways survive different DCs. Mucus-derived carbohydrates...

ABSTRACT Twenty-seven Shiga toxin-producing Escherichia coli (STEC) strains were isolated from 207 stx -positive French environmental samples. Ten of these positive for 1 , and 24 2 (10 2vh-a or 2vh-b 19 2d 15 2e ). One strain belonged to serotype O157:H7, the others serogroups O2, O8, O11, O26, O76, O103, O113, O121, O141, O166, O174. The environment is a reservoir in which new clones STEC that are pathogenic humans can emerge.

The clpG gene coding for the CS31A subunit was localized on a 0.9-kb SphI fragment from recombinant plasmid pAG315. This established by testing ability of subclones to hybridize with 17-meric oligonucleotide probe obtained N-terminal analysis subunit. nucleotide sequence region determined. From primer extension analysis, two initiation translation start sites were detected. Two possible promoterlike sequences identified; ribosome binding site and terminator are proposed. Inverted repeat...

The gastrointestinal tract (GIT) of healthy cattle is the main reservoir enterohaemorrhagic Escherichia coli (EHEC). Therefore, it crucial to better understand physiology EHEC in bovine GIT. In this study, we demonstrate that aspartate present small intestine content (BSIC), was exhausted after incubation reference strain EDL933 but poorly assimilated by endogenous microbiota. Furthermore, commensal E. BG1 appeared less efficient than assimilation suggesting a competitive ability assimilate...

To assess the role of aerobactin-related system in virulence bovine opportunistic Escherichia coli, and to determine stage(s) overall infectious process at which it is acting, germfree lambs were mixedly infected orally with two derivative strains this bacterium differing their ability (Iut+) or inability (Iut-) express a functional aerobactin-mediated iron transport system. The Iut- strain was compared Iut+ for colonization gut, translocation mesenteric lymph nodes (MLN), spread other...

Abstract Background Enterohemorrhagic Escherichia coli (EHEC) are responsible for severe diseases in humans, and the ruminant digestive tract is considered as their main reservoir. Their excretion bovine feces leads to contamination of foods environment. Thus, providing knowledge processes used by EHEC survive and/or develop all along gut represents a major step strategies implementation. Results We compared transcriptome reference strain EDL933 incubated vitro triplicate samples sterile...

The association of the pap operon with CS31A and F17 adhesins was studied 255 Escherichia coli strains isolated from calves, lambs, or humans diarrhea. three classes PapG adhesin different receptor binding preferences were also screened. associated 50 36% human that produced ovine F17, respectively. Among bovine isolates, detected in 61% CS31A-positive isolates 72% produce both F17. class II gene present (20%) (71%) isolates. Both III genetically strains. highest prevalence observed among E....