Yersinia enterocolitica in a Brazilian pork production chain: Tracking of contamination routes, virulence and antimicrobial resistance

This study aimed to track Yersinia enterocolitica contamination in a pork production chain in Minas Gerais, Brazil, and to characterize the virulence and antibiotic resistance of isolates. Samples were collected from four different steps of the pork production chain (pig farm, carcass, processing environment and end product; n = 870), and tested for the presence of Y. enterocolitica. The pathogen was detected in 8 samples (palatine tonsils = 5; mesenteric lymph nodes = 2; carcass after bleeding = 1), from which 16 isolates were obtained and identified as Y. enterocolitica bioserotype 4/O:3. XbaI macrorestriction allowed the clustering of isolates in 5 pulsetypes, and the identification of identical profiles of Y. enterocolitca isolated from different samples. All isolates were positive for the virulence related genes ail, virF, myfA, ystA, tccC, ymoA, hreP and sat, and negative for ystB, ystC, fepA, fepD and fes. Considering 17 antibiotics from 11 classes, only ciprofloxacin and kanamycin were effective against all isolates, and three multidrug resistance profiles were identified among them, with simultaneous resistance to 9 of 11 classes. All isolates presented positive results for emrD, yfhD and marC, related to multidrug resistance. The results of this study demonstrated the contamination routes of Y. enterocolitica within the assessed pork production chain, and highlighted the pathogenic potential and antibiotic resistance of this foodborne pathogen.