SAC will undertake sampling of about 1250 sheep at slaughter in Scotland. Faecal samples will be taken from sheep at four abattoirs in Scotland. These abattoirs will be spread across Scotland and chosen from areas with either high or low human rates of infection.
Microbiological examination of the faecal samples for E. coli O157 and the non-O157 VTEC serotypes (O26, O145, O103 and O111) will be undertaken. The samples with positive IMS results will be re-examined and the numbers of E. coli O157 determined.
Information on the prevalence of E. coli O157 in sheep faeces at slaughter and examination for regional and seasonal variation will complement our knowledge and assist in the refinement of current risk assessments for infection in humans. The use of established bacterial isolation and enumeration techniques will also enable comparison with accurate prevalence estimations for Scottish cattle for both E. coli O157 and non-O157 VTEC.
A previous FSAS study (S01018), compared the concentration and prevalence of E. coli O157 shed by cattle at the abattoir during the summer and winter months. This indicated that there is a higher prevalence of E. coli O157 in the winter, but higher concentrations are shed during the summer months. The peer review of this project recommended a need to understand the situation in sheep. They have previously been identified in Scotland as the source of outbreaks of human E. coli O157 infection, and a range of other serogroups have been isolated from sheep on the Continent.
This project will provide information on the frequency of high level E. coli O157 faecal shedding and establish the prevalence of faecal carriage in sheep in Scotland.
Examination for regional and seasonal variation will assist in the refinements of current risk assessments for infection in humans. Non-O157 VTEC serotypes may also emerge as more frequent human pathogens and the work carried out will define if they are common in Scottish sheep.
<p>Find more about this project and other FSA food safety-related projects at the <a href="http://www.food.gov.uk/science/research/" target="_blank">Food Standards Agency Research webpage</a>.