Enteropathogenic (EPEC), enterohaemorragic (EHEC) and verotoxigenic (VTEC) Escherichia coli in wild cervids

Aims: The aim of this study was to investigate the presence of enteropathogenic (EPEC), enterohaemorragic (EHEC) and verotoxigenic (VTEC) Escherichia coli strains in free-ranging wild ruminants in Belgium and to characterize the positive isolates (serogroups and virulence-associated factor-encoding genes). Methods and Results: Escherichia coli strains isolated from faeces of wild cervids were characterized by PCR targeting genes coding for the main virulence properties of EPEC, EHEC and VTEC strains. The prevalence rate of these pathogenic strains in faecal samples obtained from the wild ruminants was found to be 15%. No pathogenic isolate was found to belong to the O157, O26, O111, O103 or O145 serogroups. Moreover, a new gene, eibH, showing 88% identity with eibG was detected in VTEC strains. Conclusions: The results reveal that wild ruminants could be considered as a potential source of VTEC and EPEC infection for humans and possibly also for domestic ruminants. Significance and Impact of the Study: Our study suggests the potential risk of transmission of VTEC, EHEC and EPEC strains from wild ruminants to humans via the consumption of venison and to domestic ruminants because of sharing of the same pasture. Indeed, many serogroups other than O157 EHEC have also been shown to be responsible for outbreaks in humans in several countries, and studies focusing solely on O157:H7 EHEC tend to underestimate this risk of transmission.