Prevalence, Genetic Homogeneity, and Antibiotic Resistance of Pathogenic Yersinia enterocolitica Strains Isolated from Slaughtered Pigs in Bulgaria

Abstract

Yersiniosis is the third most commonly reported foodborne zoonosis in the European Union. Here, we evaluated the prevalence of pathogenic Yersinia enterocolitica among healthy pigs (as a major reservoir) in a slaughterhouse in Bulgaria. A total of 790 tonsils and feces from 601 pigs were examined. Isolation and pathogenicity characterization was carried out by the ISO 10273:2003 protocol and Polymerase Chain Reaction (PCR), detecting the 16S rRNA gene, attachment and invasion locus (ail), Yersinia heat-stable enterotoxin (ystA), and Yersinia adhesion (yadA) genes. Genetic diversity was assessed by pulsed-field gel electrophoresis (PFGE), and antimicrobial resistance by the standard disk diffusion method. Of all the pigs tested, 6.7% were positive for Y. enterocolitica. All isolates belonged to Y. enterocolitica bioserotype 4/O:3. ail, and ystA genes were detected in all positive strains (n = 43), while the plasmid Yersinia virulence plasmid (pYV) was detected in 41. High homogeneity was observed among the strains, with all strains susceptible to ceftriaxone, amikacin and ciprofloxacin, and resistant to ampicillin. In conclusion, a low prevalence of Y. enterocolitica 4/O:3 was found in healthy pigs slaughtered in Bulgaria, not underestimating possible contamination of pork as a potential risk to consumer health.

Comparative Genomics, Phylogenetic and Functional Analysis of Yersinia enterocolitica, a Gastrointestinal Pathogen, with Other Soil-Borne Bacteria Causing Diseases

“…Th e frequent application of antibiotics in veterinary medicines as growth enhancers in animals such as pigs increases the signifi cance of antimicrobial-resistant Y. enterocolitica strains resistant to ampicillin, novobiocin, cefamandole, and bacitracin. Th us, animals are carriers of this zoonotic pathogen and therefore, a surveillance system that can properly monitor Y. enterocolitica in slaughterhouses is required [36].…”

Using Essential Oils to Reduce Yersinia enterocolitica in Minced Meat and in Biofilms

“…Pigs are considered the main asymptomatic reservoir of Y. enterocolitica , especially bioserotype 4/O:3 [ 9 ]. The prevalence in Europe is estimated to be up to 93% [ 10 ]. The prevalence of Y. enterocolitica in pigs varies worldwide [ 11 , 12 ], and depends on several factors including the farm management system, conditions in slaughterhouses, and the detection methodology [ 13 ].…”