Molecular Profiling of Shiga Toxin-Producing Escherichia coli and Enteropathogenic E. coli Strains Isolated from French Coastal Environments
|Author(s)||Baliere Charlotte1, Rince A.2, Delannoy S.3, Fach P.3, Gourmelon Michele1|
|Affiliation(s)||1 : IFREMER, Dept Ressources Biol & Environm, Unite Sante Genet & Microbiol Mollusques, Lab Sante Environm & Microbiol, Plouzane, France.
2 : Normandie Univ UCBN, U2RM EA4655 Stress Virulence, Caen, France.
3 : Univ Paris Est, ANSES Food Safety Lab, Platform IdentyPath, Maisons Alfort, France.
|Source||Applied And Environmental Microbiology (0099-2240) (Amer Soc Microbiology), 2016-07 , Vol. 82 , N. 13 , P. 3913-3927|
|WOS© Times Cited||19|
|Abstract||Shiga toxin-producing Escherichia coli (STEC) and enteropathogenic E. coli (EPEC) strains may be responsible for food-borne infections in humans. Twenty-eight STEC and 75 EPEC strains previously isolated from French shellfish-harvesting areas and their watersheds and belonging to 68 distinguishable serotypes were characterized in this study. High-throughput real-time PCR was used to search for the presence of 75 E. coli virulence-associated gene targets, and genes encoding Shiga toxin (stx) and intimin (eae) were subtyped using PCR tests and DNA sequencing, respectively. The results showed a high level of diversity between strains, with 17 unique virulence gene profiles for STEC and 56 for EPEC. Seven STEC and 15 EPEC strains were found to display a large number or a particular combination of genetic markers of virulence and the presence of stx and/or eae variants, suggesting their potential pathogenicity for humans. Among these, an O26:H11 stx1a eae-β1 strain was associated with a large number of virulence-associated genes (n = 47), including genes carried on the locus of enterocyte effacement (LEE) or other pathogenicity islands, such as OI-122, OI-71, OI-43/48, OI-50, OI-57, and the high-pathogenicity island (HPI). One O91:H21 STEC strain containing 4 stx variants (stx1a, stx2a, stx2c, and stx2d) was found to possess genes associated with pathogenicity islands OI-122, OI-43/48, and OI-15. Among EPEC strains harboring a large number of virulence genes (n, 34 to 50), eight belonged to serotype O26:H11, O103:H2, O103:H25, O145:H28, O157:H7, or O153:H2.|