Phenotypic and Genotypic Characterization of Escherichia coli Verotoxin-Producing Isolates from Humans and Pigs
Abstract:The aim of this study was to characterize verotoxin-producing Escherichia coli (VTEC) isolates obtained from humans and pigs in the same geographic areas and during the same period of time in order to determine whether porcine VTEC isolates could be related to human cases of diarrhea and also to detect the presence of virulence factors in these isolates. From 1,352 human and 620 porcine fecal samples, 11 human and 18 porcine verotoxin-positive isolates were obtained by the VT immunoblot or the individual colony testing technique. In addition, 52 porcine VTEC strains isolated from diseased pigs at the Facultéde médecine vétérinaire during the same period or from fecal samples collected previously isolated at slaughterhouses were characterized in this study. Antimicrobial resistance profiles were different between human and porcine isolates. In general, the serotypes observed in the two groups were different. No porcine isolate was of serotype O157:H7; however, one isolate was O91:NM, a serotype that has been associated with hemorrhagic colitis in humans. Also, one serotype (O8:H19) was found in isolates from both species; however, the O8:H19 isolates of the two groups were of different pathotypes. The pathotypes observed in the human and porcine isolates were different, with the exception of VT2vx-positive isolates; the serotypes of these isolates from the two groups were nevertheless different. Pulsed-field gel electrophoresis analysis indicated no relatedness between the human and porcine isolates. In conclusion, these results suggest that the porcine and human isolates of the present study were not genetically related. Most porcine VTEC isolates did not possess known virulence factors required to infect humans. However, certain non-O157:H7 porcine VTECs may potentially infect humans.
Document Type: Research Article
Affiliations: 1: Département de pathologie et de microbiologie, Facultéde médecine vétérinaire, Universitéde Montréal, C.P. 5000, St-Hyacinthe, Québec, Canada J2S 7C6 2: Département de pathologie et de microbiologie, Facultéde médecine vétérinaire, Universitéde Montréal, C.P. 5000, St-Hyacinthe, Québec, Canada J2S 7C6 3: Laboratory for Foodborne Zoonoses, Health Canada, 110 Stone Road West, Guelph, Ontario, Canada N1G 3W4 4: Département de pathologie et de microbiologie, Facultéde médecine vétérinaire, Universitéde Montréal, C.P. 5000, St-Hyacinthe, Québec, Canada J2S 7C6
Publication date: 2001-12-01
- The Journal of Food Protection has moved to a new website. Please use http://jfoodprotection.org to access the Journal of Food Protection and Journal of Milk & Food Technology content on the new JFP site. Content on the IngentaConnect website will not be available after December 31, 2016.
- Information for Authors
- Submit a Paper
- Subscribe to this Title
- Membership Information
- Information for Advertisers
- Ingenta Connect is not responsible for the content or availability of external websites