Microbial contamination on beef and sheep carcases in South Australia

A total of 523 chilled beef and lamb carcases were sampled from four abattoirs and 13 very small plants (VSPs) in South Australia during March 2002 in order to develop a microbiological profile of meat produced for domestic consumption within the State. Aerobic viable counts (AVCs) and Escherichia coli counts were obtained from samples taken by sponge-sampling the muscle-adipose tissue at sites designated for each species in the Microbiological Guidelines to the Australian Standard for Hygienic Production of Meat for Human Consumption (identical with those of the USA Pathogen Reduction: hazard analysis and critical control point (HACCP) systems: final rule). On beef carcases (n=159) mean log AVC/cm2 was 1.82 and E. coli was detected on 18.8% of carcases (area sampled 200 cm2) for which the mean log of the positives was −0.34; for lamb carcases, on which 75 cm2 was sampled (n=364), corresponding values were 2.59, 36.2% and log10 0.27, respectively. There was little difference in mean log AVC/cm2 of carcases produced at abattoirs and VSPs, 1.72 versus 1.81, respectively, for beef, and 2.80 versus 2.44, respectively, for sheep. Prevalence of E. coli was lower at VSPs, however, with abattoirs having 28.4% for beef and 61.5% for sheep, compared with corresponding values of 4.7% and 18.5% at VSPs. In VSPs, the range of mean log AVC/cm2 was 0.47–3.16 for beef and 1.63–3.65 for sheep carcases, data which will allow the Controlling Authority to assist plants to improve performance of slaughter and dressing techniques. The present survey is part of an assessment by the State meat authority of the effectiveness of co-regulation of meat hygiene between government and industry.