Effects of Antimicrobial Interventions on Indicator Organisms during Beef Carcass Dressing

ABSTRACT

Beef slaughter establishments employ many interventions to help minimize the occurrence of pathogens in their products. This study explored the effectiveness of various common interventions on microbial load using the results of the Beef-Veal Carcass Baseline Survey conducted in 2014 to 2015. The Food Safety and Inspection Service analyzed swab samples taken from 1,135 carcasses at 139 establishments. These included paired samples from post-hide removal (before evisceration) and prechill (after evisceration). Samples were tested for pathogens (Salmonella and Shiga toxin-producing Escherichia coli) and indicators (E. coli, Enterobacteriaceae, coliforms, and aerobic count [AC]). The sample size for pathogen-positive samples was small, impeding the establishment of a direct correlation between interventions and pathogens. However, we observed associations between pathogen-positive rate and log AC, indicating similar intervention effectiveness of pathogens and indicators in this study. Generally, the use of interventions reduced indicator concentrations. Each intervention produced a range of effectiveness, suggesting that how interventions are applied may be as important as which interventions are applied. The range of effectiveness for single interventions was a 0.4- to 1.9-log AC reduction; for multihurdle interventions, it ranged from 1.6- to 2.9-log AC reduction. The results of this study may be used by slaughter establishments to help identify effective intervention options for pathogen reduction.

HIGHLIGHTS

Salmonella and Shiga Toxin-Producing Escherichia coli in Products Sampled in the Food Safety and Inspection Service Raw Pork Baseline Study

The Food Safety and Inspection Service (FSIS) conducts microbiological baseline studies to determine national prevalence of select foodborne pathogens in federally inspected meat and poultry products and to obtain data for risk assessments. The FSIS conducted a baseline study from 1 June 2017 through 31 May 2018 to characterize and determine the prevalence of Salmonella and assess the occurrence of Shiga toxin-producing Escherichia coli (STEC) in a variety of raw pork products. In total, 4,014 samples from slaughter and processing establishments were analyzed for Salmonella; a subset of these samples (1,395) from slaughter establishments were also analyzed for STEC. Analyses determined that the national prevalence of Salmonella in raw pork products was highest in comminuted products (28.9%), followed by intact cuts (5.3%) and nonintact cuts (3.9%). Less than 1% of samples analyzed were positive for the top seven STEC. Our findings indicate there is a need for additional pathogen reduction strategies for raw pork products.

Survey of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and non-ortho-polychlorinated biphenyls in U.S. meat and poultry, 2007-2008: effect of new toxic equivalency factors on toxic equivalency levels, patterns, and temporal trends

A statistically based survey of dioxins and dioxin-like compounds in domestic meat and poultry was conducted by the U.S. Department of Agriculture (USDA) from September 2007 to September 2008. Seventeen toxic polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and four non-ortho-polychlorinated biphenyls (no-PCBs) were measured in 510 beef (steer/heifer), market hog, young turkey, and young chicken samples. The results of the survey showed the sum of PCDD/F and no-PCB toxic equivalencies (sum-TEQs) ranging from not detected to 4.5 pg/g of lipid. Mean sum-TEQ levels for beef, turkey, chicken, and pork were 0.66, 0.61, 0.17, and 0.16 pg/g of lipid, respectively. To compare the new survey data with data from previous USDA surveys in the mid-1990s and 2002-2003, TEQs from all data sets were calculated using the most recent 2005 toxic equivalency factors (TEFs). The results of the recalculation on the older survey data was a small increase (4-13%) in mean TEQs for the mid-1990s data, which initially used pre-1994 TEFs, and a small decrease (2-4%) for the 2002-2003 data, which initially used 1998 TEFs. A comparison of the three surveys indicates declining TEQ trends in all slaughter classes over the 10 year period; however, the congener patterns remain relatively constant between 2002 and 2008, indicating similar animal exposures to dioxins and dioxin-like compounds during these time periods. Several samples from the 2008 survey with the highest TEQ values are undergoing follow-up investigations to determine possible sources that may be contributing to these levels.