Enterohemorrhagic E. coli are notifiable zoonotic agents which can cause severe illnesses in humans, especially in young children and the elderly. In the 1980s the majority of EHEC infections occurred due to EHEC-contaminated food. Nowadays, environmental transmission is on the rise and constitutes an important new route of infection. Cattle and other domestic and wild ruminants have been identified as the main reservoirs which carry the pathogen asymptomatically.
In Austria there is only few data describing the role of animal-reservoirs from a public health perspective, the aim of this survey was to shed light on the potential presence of EHEC in native wild and domestic animals. In course of this study we analyzed fresh fecal samples from cattle and free-ranging chamois between June-August 2009 (5 samplings in total) from an alpine pasture in the northern Limestone Alps. We screened for three virulence genes (stx1, stx2, eae) and rfbE, a gene specific for E.coli O157. The study showed high prevalence of all three virulence genes in both, cattle and chamois. E.coli O157, the most common serogroup of EHEC associated with severely ill patients, were detectable in cattle but were not found in chamois. However, our study represents the first report on the confirmed finding of EHEC in chamois. Inter-species transmission is assumed, and this promotes the spread of newly acquired EHEC strains in the farm and mountain environment, respectively. Since the northern Limestone Alps also serve as a recreational area, EHEC-shedding animals grazing on this alpine pasture pose a potential public health risk.
Strategies to reduce EHEC shedding in reservoirs and hence, decrease environmental contamination need additional research. Informing the public about risk factors, surveillance via standardized monitoring-programs as well as establishment of reference laboratories are important tools to keep human infections to a minimum.
EHEC, enterohemorrhagic E. coli, STEC, cattle, chamois, Rupicapra rupicapra, prevalence, E. coli O157