Purpose: This study aimed to verify the distribution of Salmonellaspp. along a pork production chain, including farming and slaughtering, and to characterize virulence markers in the obtained isolates.
Methods: Two pig farms and a slaughterhouse were selected for sampling different production steps of ten pig lots, resulting in 670 samples (finishing barns: 20, swine carcasses: 400, equipment and utensils: 180, end products: 70). Samples were subjected to Salmonella spp. detection according ISO 6579, and suspect isolates were subjected to PCR targeting invA and ompC. Salmonella spp. isolates were subjected to PCR to detect 15 virulence related genes (despite invA).
Results: In pig farms, nine finishing barns (45.0%) were Salmonella spp. positive, while only end products in the slaughterhouse, specifically fresh sausages, presented the pathogen (n=6, 8.6%). A total of 42 Salmonella spp. isolates were identified by presenting invA and/or ompC (barns: 17; sausages: 25). Different frequencies of virulence related genes were identified among isolates, being cdtB (n=13, 31.0%) and iroN (n=23, 54.8%) the less frequent, while sitC, pagC, prgH, sopB and spaN were detected in all isolates (n=42, 100%); invAwere identified in 35 (83.3%) isolates. Different associations of positive results for virulence genes were recorded, and a minimum of 10 genes were identified simultaneously per isolate.
Significance: The results indicate the relevance of Salmonella spp. in the final steps of pork production and the potential risks of this pathogen to consumers.