Shiga Toxin-Producing Escherichia coli in Faecal Samples from Wild Ruminants

Wildlife can harbour Shiga toxin-producing Escherichia coli (STEC). In the present study, STEC in faecal samples from red deer (n = 106) and roe deer (n = 95) were characterised. All isolates were non-O157 strains. In red deer, STEC were detected in 17.9% (n = 19) of the isolates, and the eae/stx2b virulence profile was detected in two isolates (10.5%). One STEC strain harboured stx1a (5.3%) and eighteen STEC strains harboured stx2 (94.7%). The most prevalent stx2 subtypes were stx2b (n = 12; 66.7%), stx2a (n = 3; 16.7%), and stx2g (n = 2; 11.1%). One isolate could not be subtyped (NS) with the applied primers (5.6%). The most widely identified serotypes were O146:H28 (n = 4; 21%), O146:HNM (n = 2; 10.5%), O103:H7 (n = 1; 5.3%), O103:H21 (n = 1; 5.3%), and O45:HNM (n = 1; 5.3%). In roe deer, STEC were detected in 16.8% (n = 16) of the isolates, and the eae/stx2b virulence profile was detected in one isolate (6.3%). Two STEC strains harboured stx1a (12.5%), one strain harboured stx1NS/stx2b (6.3%), and thirteen strains harboured stx2 (81.3%). The most common subtypes were stx2b (n = 8; 61.5%), stx2g (n = 2; 15.4%), non-typeable subtypes (NS) (n = 2; 15.4%), and stx2a (n = 1; 7.7%). Serotype O146:H28 (n = 5; 31.3%) was identified. The study demonstrated that the zoonotic potential of STEC strains isolated from wildlife faeces should be monitored in the context of the ‘One Health’ approach which links human health with animal and environmental health.