Control of Escherichia coli O157:H7 using lytic bacteriophage and lactic acid on marinated and tenderized raw pork loins
Sherita Li, Haley M. Konoval, Samantha Marecek, Amanda Lathrop, Sofia Feng, Siroj Pokharel
Abstract
Escherichia coli (E. coli) O157:H7- contaminated pork and production environments, are often a major source of foodborne outbreaks. This study evaluated the inhibition of E. coli O157:H7 on artificially contaminated raw pork loins using lytic bacteriophage (phage) and lactic acid (LA). Pork samples were inoculated with 106 CFU/mL of E. coli O157:H7 cocktail and stored at 4 °C for 30 min for the initial surface attachment. Inoculated pork loins were randomly assigned to a treatment group (Control, DI water, LA 2.5%, phage 5%, and LA 2.5% + phage 5%; n = 6/group/replication). Following antimicrobial treatments and marination for 1 h, surface microbial population was enumerated. Phage 5% significantly reduced (P < 0.05) the microbial load by 1.90 logs in pre-tenderized loins and > 2.50 logs in post-tenderized loins. Likewise, the combined treatment of phage 5% and LA 2.5% significantly reduced (P < 0.05) the microbial load by 1.89 logs in pre-tenderized loins and > 1.75 logs in post-tenderized loins. The data showed that the use of lytic bacteriophages and lactic acid as antimicrobials can result in a reduced risk of E. coli O157:H7 on the surface of pork loins.