Prevalence of verotoxin-producing Escherichia coli (VTEC) in slurry, farmyard manure and sewage sludge in France

Aims: The aims of the present study were to determine VTEC prevalence in manure, slurryand sewage sludge in France and to characterize the VTEC strains isolated (virulence genes and serotype). Methods and Results: Seven hundred and fifty-two samples from 55 farmyard manures, 136 bovine and porcine faeces, 114 slurries, 10 composts, and 437 samples from outflows of sewagewastewater treatment plants were analysed. Twenty-four percent contained isolates which were PCR positive for stx gene. Twenty-one VTEC strains were recovered from positive samples by colony hybridization: 76% of them were positive for stx (2) gene, 33% for stx (1) gene,and 19% for eae gene. One strain belonged to serotype O157:H7 and two others to serogroups O26 and O55, respectively. Conclusions: Some of the VTEC strains isolated from environments in France should be considered as potentially pathogenic for humans. Significance and Impact of the Study: Appropriate handling or use of manure, slurry andsewage sludge is necessary so that contamination of the environment and food by VTEC can be prevented.