Prevalence studies on Escherichia coli O157:H7, Salmonella spp. and indicator bacteria in raw ground beef produced at federally registered establishments in Canada.

摘要

During March 2001-February 2002, a study was carried out to examine the microbiological quality of raw ground beef produced at 52 federally registered establishments in Canada. Raw ground beef samples were analysed for total aerobic counts (TAC), total generic E. coli counts (EC), E. coli O157 and Salmonella. Overall, a total of 1396 samples of raw ground beef were taken from three categories of establishments with significantly different production volumes: large, medium and small. Mean log10 TAC counts/g ranged from 3.0 to 6.4, while mean log10 generic E. coli counts/100 g ranged from 2.7 to 3.5. No significant difference was demonstrated with regard to mean log10 generic E. coli counts between different sizes of establishments, although significant differences were noted for mean log10 TAC counts between small and large or medium-size establishments. A seasonal variation was noticed during the months of June and August for mean log10 TAC counts; however, no obvious seasonal variation was observed for mean log10 E. coli counts. In total, for large, medium and small-size establishments, 0.74%, 2.1% and 0.25% of samples, respectively, were positive for E. coli O157, while 0.87%, 1.06% and 0.5% of samples, respectively, were positive for Salmonella spp.