Neutralization of residual antimicrobial processing chemicals in broiler carcass rinse for improved detection of Campylobacter1

SUMMARY The USDA-Food Safety and Inspection Service (FSIS) has established pathogen reduction performance standards for Campylobacter on broiler carcasses. Processors may apply antimicrobial processing aids as a spray or immersion to lower contamination on carcasses. In the United States, broiler carcasses are generally sampled by whole carcass rinse and the potential exists for residual levels of antimicrobial processing aid to be carried over into the rinsate. It has been shown that, if un-mitigated, such carryover can interfere with the detection of Salmonella. In the current study, we demonstrate that unmitigated carryover of antimicrobial treatment also can interfere with the detection and recovery of Campylobacter in broiler carcass rinse samples. We tested traditional buffered peptone water and found that it did not offer enough neutralizing capability to counteract residual antimicrobial activity of some post-chill processing aids (peroxyacetic acid, cetylpyridinium chloride, acidified sodium chloride, or a blend of acids) to allow full recovery of Campylobacter. A recently reported formulation for a neutralizing buffered peptone water (currently being used by FSIS) outperformed the traditional carcass rinse medium and allowed significantly improved recovery of Campylobacter even in the presence of 3 of the 4 tested antimicrobial processing aids. Performance of the new carcass rinse medium with the fourth antimicrobial processing aid (acidified sodium chloride) was not different from the traditional formulation. Neutralizing buffered peptone water represents a significant improvement in the broiler carcass rinse method for detection of Campylobacter.