CategoryPre-Harvest Pork Safety
Date Full Report Received07/20/2006
Date Abstract Report Received07/21/2008
InvestigationInstitution: Food and Feed Safety Research Unit, USDA-ARS-SPA
Primary Investigator: David J. Smith
Co-Investigators: Robin C. Anderson
Funded ByNational Pork Board
Each year thousands of US consumers become ill because they have eaten food products that are contaminated with pathogenic bacteria such as Salmonella or E. coli O157:H7. Intense efforts have been made during the last decade to eliminate pathogens which contaminate food animals. To date, no single strategy to eliminate pathogens from food animal products has been widely accepted. A new pre-harvest food safety strategy utilizing an experimental chlorate product (ECP) has been developed that greatly reduces, or even eliminates gram-negative pathogens from swine. Use of ECP has not been approved by regulatory organizations because it is not known whether residues present in edible tissues of treated animals represent a health risk to humans. The purpose of this study was to determine the magnitude and identity of ECP residues in edible tissues of growing swine after oral administration. For all of the doses tested, chlorate residues in liver, kidney, muscle, and fat always fell below 25% of the estimated FDA-estimated safe tissue concentration. The only metabolite of ECP present in tissues was chloride ion, a naturally-occuring nutrient. The study also clearly demonstrated that most of the ECP delivered in drinking water was absorbed from the gastrointestinal tract and was eliminated very rapidly in urine. Thus, delivery of the ECP to its intended site of action, the lower gastrointestinal tract, was very inefficient. Development of an ECP formulation that would prevent absorption from the upper GI tract would likely increase efficacy against pathogens in the lower gastrointestinal tract and would likely decrease tissue residues even further. Further research on ECP is warranted because ECP could have a significant impact on lowering the incidence of harmful bacteria on pork carcasses, and because tissue residues of ECP fall below levels that regulatory agencies have estimated to be safe.