FSIS Poultry Exploratory Sampling Program Report
FSIS conducted a paired sampling Salmonella study to examine the microbial profile of young chicken carcasses from the rehang step to the end of the slaughter process, i.e., post-chill step. This study found that both Salmonella incidence and aerobic indicator levels decreased significantly from rehang to post-chill, with reduction rates of 92% and 99.9%, respectively. When present, Salmonella was most often found at low levels. Eighteen point four percent of rehang carcass samples and 15.7% of post-chill carcass samples had Salmonella concentrations above the 10 CFU/mL limit of quantification (LOQ), with median values of 58 CFU/mL and 27 CFU/mL, respectively. Given the recent guidance from the National Advisory Committee on Microbiological Criteria for Foods (2023), FSIS conducted an additional study to evaluate the variability in Salmonella enumeration test results using traditional most probable number (MPN) methods compared to using newer quantitative polymerase chain reaction (qPCR) test methods. Both MPN and qPCR Salmonella enumeration methods exhibited variability at the low microbial levels typically found in poultry products. FSIS will continue to collaborate with researchers and test kit manufacturers to evaluate new methods of Salmonella quantification as they become available to identify the best method for a high-throughput regulatory laboratory environment.