Neutralization of bactericidal activity related to antimicrobial carry-over in broiler carcass rinse samples

Authors: Gamble, Gary; Berrang, Mark; Buhr, Richard - Jeff; Hinton Jr, Arthur; Bourassa, Dianna; JOHNSTON, JOHN - US Department Of Agriculture (USDA); Ingram, Kimberly; Adams, Eric; Feldner, Peggy

Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/19/2016
Publication Date: 3/17/2017
Citation: Gamble, G.R., Berrang, M.E., Buhr, R.J., Hinton Jr, A., Bourassa, D.V., Johnston, J.J., Ingram, K.D., Adams, E.S., Feldner, P.W. 2017. Neutralization of bactericidal activity related to antimicrobial carry-over in broiler carcass rinse samples. Journal of Food Protection. 80(4):685-691. doi:10.4315/0362-028x. JFP-16-412.

Interpretive Summary: Chemical antimicrobial interventions used as poultry processing aids may have potential for carry-over into whole poultry carcass buffered peptone water (BPW) rinses collected for the recovery of viable Salmonella. Such carry-over may lead to false negative indications due to continuing bactericidal action of the antimicrobials in the rinse. This study was conducted to determine whether the carry-over effect of four sanitizing chemicals commonly used as poultry processing aids for broilers in a post-chill dip may be neutralized by the incorporation of various chemical agents into BPW. The four antimicrobials tested were cetylpyridinium chloride, peroxyacetic acid, acidified sodium chlorite, and a pH=1 acid mix. The four antimicrobial solutions were prepared at maximum allowable concentration and diluted with BPW rinse that had been previously modified with various neutralizing agents to volumes simulating maximum carry-over. These solutions were then inoculated with a mixture of Salmonella serovars. The inoculated rinse was stored at 4 degrees C for 24 h and enumerated by direct plating on BG Sulfa agar. Results indicate that incorporation of optimized concentrations of highly refined soy lecithin, sodium thiosulfate and sodium bicarbonate into BPW will neutralize the expected carry-over effects of the four antimicrobials tested, allowing recovery of viable Salmonella at levels of detection equivalent to carcass rinses with no antimicrobial carry-over.

Technical Abstract: Chemical antimicrobial interventions used as poultry processing aids may have potential for carry-over into whole poultry carcass buffered peptone water (BPW) rinses collected for the recovery of viable Salmonella. Such carry-over may lead to false negative indications due to continuing bactericidal action of the antimicrobials in the rinse. This study was conducted to determine whether the carry-over effect of four sanitizing chemicals commonly used as poultry processing aids for broilers in a post-chill dip may be neutralized by the incorporation of various chemical agents into BPW. The four antimicrobials tested were cetylpyridinium chloride, peroxyacetic acid, acidified sodium chlorite, and a pH=1 acid mix. The four antimicrobial solutions were prepared at maximum allowable concentration and diluted with BPW rinse that had been previously modified with various neutralizing agents to volumes simulating maximum carry-over. These solutions were then inoculated with approximately 106 CFU/ml of a mixture of 5 nalidixic acid resistant Salmonella serovars. The inoculated rinse was stored at 4 degrees C for 24 h and enumerated by direct plating on BG Sulfa agar supplemented with nalidixic acid. Results indicate that incorporation of optimized concentrations of highly refined soy lecithin, sodium thiosulfate and sodium bicarbonate into BPW will neutralize the expected carry-over effects of the four antimicrobials tested, allowing recovery of viable Salmonella at levels of detection equivalent to carcass rinses with no antimicrobial carry-over.