Application of molecular typing in establishing the dynamics of enteric contamination within high capacity pork slaughter lines

By using a combination of plate counts and molecular typing (ERIC-PCR) the dynamics of enteric contamination (generic Escherichia coli and Salmonella) within two high capacity pork slaughter lines has been established. The holding area and Scraping operation were found to be key cross-contamination sites for the transfer of enteric contamination between carcasses. Holding pigs for extended periods prior processing had a significant impact on the contamination within the line (hence carcasses) throughout the entire processing activity. Salmonella appeared to become established on polisher blades to a greater extent than E. coli. Indeed, positive Salmonella carcasses following deharing frequently tested negative for E. coli. Genotypes (E. coli and Salmonella) persisted within the line to varying degrees. Attempts to identify different physiological traits between transient and endemic genotypes proved unsuccessful. The study has demonstrated the utility of molecular typing in developing and verifying HACCP plans within the pork processing industry.