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

Abstract

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.

Shiga Toxin Subtypes Associated with Shiga Toxin–ProducingEscherichia coliStrains Isolated from Red Deer, Roe Deer, Chamois, and Ibex

“…In contrast the ehxA gene was found in high prevalence (46%). These results are in agreement with previous studies on STEC isolates from wild ruminants (Gilbreath et al, 2009;Sánchez et al, 2009;Bardiau et al, 2010).…”

“…In STEC strains characterized in this study, stx2 was the predominant stx gene identified, a result which is in agreement with previous studies on STEC isolates from wild ruminants (Sanchez et al, 2009;Bardiau et al, 2010;Kistler et al, 2011) or isolates from game meat (Miko et al, 2009). With respect to the stx subtypes (according to the established new Stx nomenclature) (Persson et al, 2007), stx2b was the predominant variant among the STEC isolates in the present study.…”

“…Nevertheless, wild ruminants may be a potential reservoir and therefore a source for human infections (Asakura et al, 1998;Sanchez et al, 2009;Bardiau et al, 2010;Kistler et al, 2011), and deer meat has been implicated in the transmission of STEC to humans (Keene et al, 1997;Rabatsky-Ehr et al, 2002;Ahn et al, 2009;Rounds et al, 2012). Minimal characterization data are available so far for STEC strains from wild ruminants and also for stx subtypes and virulence factors of non-O157 STEC strains from wild ruminants.…”

Microbiome analysis reveals the abundance of bacterial pathogens in Rousettus leschenaultii guano

“…Few studies have indicated the presence of virulence genes in wild animals4041. Cabal et al 42 compared the virulence gene profile of E. coli isolated from cattle, swine and broiler.…”

Animal Reservoirs of Shiga Toxin-ProducingEscherichia coli

“…Similarly, low STEC prevalences of 0.2% were reported in hunter-harvested captive deer in Louisiana (63) and 3.3% in farm-raised deer in Ohio (64). Other species of deer, including red deer (Cervus elaphus), fallow deer (Dama dama), and roe deer (Capreolus capreolus), have also been identified as capable of shedding STEC serotypes (65,66). Almost 50% of Pennsylvanian white-tailed deer fecal samples screened tested positive for stx genes; however, only 8% possessed the eae gene, which is necessary for colonization of the human intestine (67).…”