CategoryPre-Harvest Pork Safety
Date Full Report Received06/23/2008
Date Abstract Report Received06/23/2008
InvestigationInstitution: Ohio State University
Primary Investigator: Tom Wittum
Co-Investigators: Julie Funk
Funded ByNational Pork Board
Salmonella and Campylobacter are estimated to cause 3.9 million illnesses annually in the United States, and most of these illnesses are food-related. Pigs can be sub-clinically infected with these pathogens and fecal contamination of meat during processing is a food safety risk. Quantitative measures of foodborne safety risk are rarely reported and are a critical data gap for development of quantitative risk assessments. The goal of this study was to determine the association between the concentration of Salmonella and Campylobacter in porcine feces and hide with concentrations in meat. Methods: Samples were collected 5 times from 100 individually identified pigs during the peri-harvest period. Feces were collected on the farm and in lairage. A hide swab was collected before scalding and the entire carcass was swabbed immediately before chilling. For each individually identified carcass a meat sample was collected. Salmonella and Campylobacter was cultured and quantified at each stage using the Most Probable Number Method and Real Time PCR. Results: Salmonella was culture positive from two samples (one farm sample and one lairage sample from different pigs). The proportion (%) of samples that were Campylobacter positive for MPN method was 90, 94.6, 75.5, 100, and 48.9 for farm, lairage, hide, carcass and rib samples respectively. The proportion (%) of samples that were Campylobacter positive for Real Time PCR was 48, 57, 68, 69, 40, 0, and 0 for fecal sample from farm, fecal sample from lairage, hide swab, carcass swab, ground meat and rib samples respectively The mean Campylobacter concentration for each sample type for MPN method was: farm, 1,665,122.9 cfu/g; lairage, 12,014,729.5 cfu/g; hide, 1.4 cfu/cm2; carcass, 1733.9 cfu/half carcass; and ribs, 17.5 cfu/g. The mean Campylobacter concentration for each sample type for Real Time PCR was: fecal sample from farm, 1,665,122.9 cfu/g; fecal sample from lairage, 12,014,729.5 cfu/g; hide swab, 1.4 cfu/cm2; carcass swab, 1733.9 cfu/half carcass; and ribs, 17.5 cfu/g. A weak positive correlation between Campylobacter concentrations in feces (farm, R=0.2 [p=0.065] and lairage, R=0.2[p=0.068]) and concentration of Campylobacter on meat was found using the Spearman’s rank coefficient for the MPN method. No associations were found on qualitative measures using odds ratios for the MPN method.