Indicator organisms in meat and poultry slaughter operations: their potential use in process control and the role of emerging technologies.

Measuring commonly occurring, nonpathogenic organisms on poultry products may be used for designing statistical process control systems that could result in reductions of pathogen levels. The extent of pathogen level reduction that could be obtained from actions resulting from monitoring these measurements over time depends upon the degree of understanding cause-effect relationships between processing variables, selected output variables, and pathogens. For such measurements to be effective for controlling or improving processing to some capability level within the statistical process control context, sufficiently frequent measurements would be needed to help identify processing deficiencies. Ultimately the correct balance of sampling and resources is determined by those characteristics of deficient processing that are important to identify. We recommend strategies that emphasize flexibility, depending upon sampling objectives. Coupling the measurement of levels of indicator organisms with practical emerging technologies and suitable on-site platforms that decrease the time between sample collections and interpreting results would enhance monitoring process control.

Enumeration of Escherichia coli cells on chicken carcasses as a potential measure of microbial process control in a random selection of slaughter establishments in the United States.

To evaluate whether the number of Escherichia coli bacteria in carcass rinses from chicken slaughter establishments could be monitored for the purpose of microbial process control, we drew a random sample from 20 of 127 large USDA-inspected operations. In 2005, every 3 months, two sets of 10 carcass rinses, 100 ml each, were collected from establishments, netting 80 sample sets from the rehang and postchill stages. E. coli and Campylobacter numbers and Salmonella prevalence were measured. Mixed-effect models were used to estimate variance of mean log(10) E. coli cell numbers of 10-carcass rinse sample sets. Relationships between E. coli and Campylobacter and Salmonella were examined. For 10-carcass rinse sets, at both the rehang and postchill stages the mean log(10) E. coli CFU/ml fit the logistic distribution better than the normal distribution. The rehang overall mean log(10) E. coli was 3.3 CFU/ml, with a within-sample set standard deviation of 0.6 CFU/ml. The overall postchill mean log(10) E. coli was 0.8 CFU/ml, with 13 establishments having mean log(10) E. coli CFU/ml values of less than 1.0 and 7 having mean values of 1.2 or more. At the midpoint separating these establishments, a mean log(10) E. coli CFU/ml of 1.1, the within-sample set standard deviation was 0.5 CFU/ml, with smaller standard deviations as means increased. Postchill sample sets with mean log(10) E. coli counts less than or equal to 1.1 CFU/ml had lower overall prevalence of Salmonella and mean log(10) Campylobacter CFU/ml than sample sets with higher means. These findings regarding reductions in E. coli numbers provide insight relevant to microbial process control.

Salmonella Enteritidis in meat, poultry, and pasteurized egg products regulated by the U.S. Food Safety and Inspection Service, 1998 through 2003.

The U.S. Food Safety and Inspection Service (FSIS) tests for Salmonella in meat, poultry, and egg products through three regulatory testing programs: the Pathogen Reduction-Hazard Analysis and Critical Control Point (PR-HACCP) program, the ready-to-eat program for meat and poultry products, and the pasteurized egg products program. From 1998 through 2003, 293,938 samples collected for these testing programs were analyzed for the presence of Salmonella enterica serotypes. Of these samples, 12,699 (4.3%) were positive for Salmonella, and 167 (1.3%) of the positive samples (0.06% of all samples) contained Salmonella Enteritidis. The highest incidence of Salmonella Enteritidis was observed in ground chicken PR-HACCP samples (8 of 1,722 samples, 0.46%), and the lowest was found in steer-heifer PR-HACCP samples (0 of 12,835 samples). Salmonella Enteritidis isolates were characterized by phage type, pulsed-field gel electrophoretic pattern, and antimicrobial susceptibility. Phage typing of 94 Salmonella Enteritidis isolates identified PT13 (39 isolates) and PT8 (36 isolates) as the most common types. One isolate from a ready-to-eat ham product was characterized as PT4. Electrophoretic analysis of 148 Salmonella Enteritidis isolates indicated genetic diversity among the isolates, with 28 unique XbaI electrophoretic patterns identified. Of these 148 isolates, 136 (92%) were susceptible to each of 16 antimicrobials tested. Two isolates were resistant to ampicillin alone, and 10 isolates were resistant to two or more antimicrobials. Isolation of Salmonella Enteritidis from FSIS-regulated products emphasizes the need for continued consumer education on proper food handling and cooking practices and continued work to decrease the prevalence of Salmonella in meat, poultry, and pasteurized egg products.

Food Safety and Regulatory Aspects of Cattle and Swine Cysticercosis.

Using slaughter disposition data maintained by the Food Safety and Inspection Service (FSIS) of the U.S. Department of Agriculture, prevalence of cattle cysticercosis ( Cysticercus bovis ) for a l0-year period from 1985 through 1994 is reported. Out of an annual average of approximately 33 million slaughtered cattle, about 6,200 carcasses were identified with cysticercus lesions. In the five FSIS inspection regions in the United States, namely Western, Southwestern, Northeastern, Southeastern, and North Central, an average cattle cysticercosis prevalence of 0.0697, 0.0085,0.0012,0.0004, and 0.0003, respectively, is reported. The relevance of serological testing in lieu of, or as a supplement to, the current labor-intensive physical detection procedure in cattle is discussed, the latter being reported to miss close to one-third of the carcasses harboring cysticercus lesions. Out of a total of approximately 80 million swine slaughtered annually in the United States, the number of carcasses identified with cysticercus lesions ( Cysticercus cellulosae ) is extremely low, ranging from 1 through 44 during each of the 10 years. Swine cysticercosis (unlike cattle cysticercosis), with man being an alternate intermediate host, poses serious public health concerns with sometimes fatal consequences manifested through neurocysticercosis ( Cysticercus cellulosae ). Though human cysticercosis is still rare in the United States, recent reports have indicated an upturn in diagnosed cases. These are primarily the result of an increasing number of immigrants and international travel to and from endemic areas.