Salmonella Prevalence is Low in Deep Tissue Lymph Nodes of Hog Carcasses from a Pork Processing Plant in Alberta, Canada

Deep tissue lymph nodes (DTLNs) could be an important source of Salmonella in pork because carcass decontamination strategies have no effect on Salmonella cells that are deeply embedded and protected. The objective of this study was to determine the prevalence, concentration, and antimicrobial resistance of Salmonella in DTLNs in chilled hog carcasses as well as in ground pork. A total of 400 DTLNs were collected over a 10-month period from a commercial pork processing plant. Salmonella was detected in 2 (0.5%) of 400 DTLNs; Salmonella Uganda was detected in a DTLN from the belly and Salmonella Bovismorbificans in one DTLN from the shoulder. Salmonella Uganda was also detected in one ground pork sample. The three Salmonella isolates were susceptible to all antimicrobials tested, and no clinically significant antimicrobial resistance genes were detected in these genomes after sequencing. The prevalence of Salmonella in DTLNs in pork tissues intended for human consumption is very low and could be a minor source of contamination in the production of ground pork. These findings are important for the pork industry to assess the risks and benefits of removing DTLNs from pork cuts and trimmings.