Microbial profiles of carcasses and minced meat from kangaroos processed in South Australia.

The microbiological profiles of kangaroo carcasses and minced meat at game meat processing plants in South Australia were determined in surveys undertaken in 2002 and 2004. In 2002 mean values for log(10) total viable counts (TVC) on carcasses at individual plants ranged from 0.9 to 3.9 log(10) cfu/cm(2), with the mean for all plants being 2.3 log(10) cfu/cm(2). In 2004 the between plant range was narrower, by about 1 log unit, and the mean value for carcasses at all plants was 1.2 log(10) cfu/cm(2). Minced kangaroo meat, was sampled in 2002 only. The overall mean log(10) TVC was 3.9 log(10) cfu/g, with mean counts at individual plants ranging from 3.1 to 4.6 log(10) cfu/g. The overall prevalence of E. coli was 70%, with mean numbers of 2.1 log(10) cfu/g on positive samples. Salmonella was not detected in any of 60 samples from carcasses in 2002. However, in 2004 Salmonella was detected in 4/385 samples (1.04%, 95% CI: 0.28%-2.64%). In minced kangaroo meat, Salmonella was detected in 9/50 (18%, 95% CI: 9%-31%) samples. The abdominal cavity, sampled in 2004, was found to be highly contaminated, with E. coli isolated from 46% of samples and the mean number for positive samples being 2.7 log(10) cfu/cm(2); Salmonella was isolated from 14/120 (12%; 95% CI: 6.52%-18.80%) of abdominal cavities. The practice of collecting carcasses together and pushing grouped carcasses into the chiller likely leads to cross contamination of carcasses from the abdominal cavities of others. To align results of sampling by swabbing for domestic purposes with excision sampling, required for export purposes, both methods were used to sample opposite sides of each of the 50 carcasses sampled in 2004. The results obtained with the two methods of sampling were similar.

Effect of acidified sodium chlorite treatment on chicken carcases processed in South Australia.

A trial on the effectiveness of acidified sodium chlorite (ASC) on Salmonella and Campylobacter was undertaken on chicken carcases after they exited the screw chiller of a commercial premises in Adelaide, Australia. On untreated carcases mean log10 total viable count (25 degrees C) was 2.78/cm2 compared with 1.23/cm2 on treated carcases. Prevalence of E. coli, Salmonella and Campylobacter was 100%, 90% and 100% respectively, on untreated carcases and 13%, 10% and 23% respectively, on treated carcases. The distributions of E. coli, Salmonella and Campylobacter (mean log10 of positive samples) from untreated carcases were 1.55, -1.80 and 1.59/cm2 respectively, and -0.64, -1.85 and -2.21/cm2 respectively, on treated carcases. On untreated carcases S. Sofia and S. Infantis were isolated from 73% and 37% of carcases, respectively; only S. Sofia was isolated from treated carcases. The significant reductions in both prevalence and concentration demonstrated in the present trial indicate that ASC is a risk management option immediately available to the poultry industry.

Have changes to meat and poultry food safety regulation in Australia affected the prevalence of Salmonella or of salmonellosis?

During the 1990s, there was radical change in regulation of meat and poultry hygiene in Australia, and Australian Standards were developed for each sector of the meat industry. Systems for industry/government co-regulation and company-employed meat inspection were introduced based on company HACCP programs approved and audited by the Controlling Authority. However, in the 5 years since regulatory changes took full effect, rates of salmonellosis have not decreased (surveillance and reporting systems have remained unchanged). Using statistics gathered by the National Enteric Pathogens Surveillance Scheme, an attempt was made to link Salmonella serovars isolated from meat and poultry with those causing salmonellosis. Two periods were studied, 1993/1994, before regulations were introduced, and 2000/2001, when regulations should be having an effect. For red meat, the same serovars were prominent among the top 10 isolates both before and after regulation, and there was little linkage with salmonelloses. For poultry, frequently isolated serovars differed pre- and post-regulation, however, in both periods there was some linkage between serovars isolated from poultry and those causing salmonelloses. Using published and unpublished survey data, it was concluded that there had been improvements in microbiological quality of red meat and poultry over the same timeframe as regulatory changes. That these improvements apparently have not carried through to reduced case-rates for salmonellosis may be due to numerous causes, including lack of control in the food processing, food service and home sectors. The present paper illustrates difficulties faced by governments in measuring public health outcomes of changes to food hygiene regulation.

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/cm(2) was 1.82 and E. coli was detected on 18.8% of carcases (area sampled 200 cm(2)) for which the mean log of the positives was -0.34; for lamb carcases, on which 75 cm(2) was sampled (n=364), corresponding values were 2.59, 36.2% and log(10) 0.27, respectively. There was little difference in mean log AVC/cm(2) 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/cm(2) 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.