Recent introduction of PCR testing for E. coli O157 and expansion of testing to include an additional six Shiga-toxigenic E. coli (STEC) has meant that the Australian industry is faced with increased detections of these pathogens. This is due to the larger number of pathogens of concern as well as the increased sensitivity of the diagnostic tests, despite meat processing practices remaining largely unchanged. Further, existing process control measures, including Product Hygiene Index and E. coli and Salmonella Monitoring (ESAM), are focussed on general processing hygiene and have been shown to have low ability to predict likely pathogen detections. That is, the presence of STEC confirmation has occurred despite generic E. coli not being detected on carcases, or at very low levels, and little or no visual carcase contamination.
This project was undertaken to assess slaughter processes that ensure a very low prevalence of undesirable enteric microorganisms and to propose alternative testing systems to identify significantly increased risk of the detection of pathogenic E. coli. A range of investigations were undertaken and important practices were collated in a revision of the MLA "Incoming livestock and slaughter process assessment tool for beef". Alternative test systems should include larger sampling areas, higher risk carcase sites, microbial indicators that are more frequently detected than E. coli, and better alignment between carcase and carton samples to allow better through-chain assessment of microbial contamination.
A processor was interested to determine whether or not expanded microbiological process control measuring, similar to United States Department of Agriculture (USDA) Agircultural Research Service (ARS) and IEH Harvest Monitoring, would assist the company in identifying areas to affect process control improvements and reduce the risk of STEC detections impacting operations.