Genetic Diversity and Distribution of Virulence-Associated Genes in Y. enterocolitica and Y. enterocolitica-Like Isolates from Humans and Animals in Poland

Abstract

Yersinia enterocolitica, widespread within domestic and wild-living animals, is a foodborne pathogen causing yersiniosis. The goal of this study was to assess a genetic similarity of Y. enterocolitica and Y. enterocolitica-like strains isolated from different hosts using Multiple Locus Variable-Number Tandem Repeat Analysis (MLVA) and Pulsed-Field Gel Electrophoresis (PFGE) methods, and analyze the prevalence of virulence genes using multiplex-Polymerase Chain Reaction (PCR) assays. Among 51 Yersinia sp. strains 20 virulotypes were determined. The most common virulence genes were ymoA, ureC, inv, myfA, and yst. Yersinia sp. strains had genes which may contribute to the bacterial invasion and colonization of the intestines as well as survival in serum. One wild boar Y. enterocolitica 1A strain possessed ail gene implying the possible pathogenicity of 1A biotype. Wild boar strains, represented mainly by 1A biotype, were not classified into the predominant Variable-Number Tandem Repeats (VNTR)/PFGE profile and virulotype. There was a clustering tendency among VNTR/PFGE profiles of pig origin, 4/O:3, and virulence profile. Pig and human strains formed the most related group, characterized by ~80% of genetic similarity what suggest the role of pigs as a potential source of infection for the pork consumers.

Evaluation of the Correlation between the mRNA Expression Levels of ystA and ymoA Genes in Y. enterocolitica Strains with Different Enterotoxic Properties

“…Pigs are the main reservoir of Y. enterocolitica and a source of infection for humans. The presence of correlations between strains isolated from healthy pigs and humans with yersiniosis has been frequently confirmed by other researchers [ 7 , 8 , 9 , 10 ]. Undercooked pork is regarded as the main source of infection, but cross-contamination is also possible.…”

Virulence Determinants and Genetic Diversity of Yersinia Species Isolated from Retail Meat

“…hreP, fepD, sat and fes genes were mostly associated with Y. enterocolitica 1A [44]. Occasionally, those genes were reported in pathogenic isolates, e.g., fepD (enrochelin ABC transporter) in Y.enterocolitica 1B/O:8 or sat (streptogramin acetyltransferase) in 1B/O:8, 4/O:3 and 3/O:3 bioserovars [19,54,55].…”

“…ymoA, fepD and fes genes were the most common in the Yersinia species, while Y. enterocolitica harbored hreP, inv, myfB, myfC, sat and ymoA virulence genes. ymoA (modulator of the expression of virulence function) was identified in 100% of Y. enterocolitica isolated previously [19]. hreP, fepD, sat and fes genes were mostly associated with Y. enterocolitica 1A [44].…”

“…Pathogenic Y. enterocolitica has been frequently isolated from pork-retail cuts, minced pork, offal and pork sausages-with the majority of isolated strains belonging to the same bioserotypes that were identified in pigs-4/O:3 [13][14][15][16][17]. Undercooked pork meat has been significantly associated with sporadic yersiniosis cases, but the genetic similarity between the human and porcine isolates indicates transmission through the pork production chain [10,18,19]. Thus, studies on the prevalence of pathogenic Yersinia species in meats are important for the recognition of foodborne transmission and the assessment of the distribution within the food chain.…”

“…Notwithstanding, the presence of virulence markers, including the ail gene, was reported in non-pathogenic Yersinia species and Y. enterocolitica 1A isolates [22]. Therefore, the characterization of virulence factors in Yersinia isolates is important for an understanding of the pathogenicity potential of the Yersinia species as different Y. enterocolitica virulotypes and virulence traits could be established in Yersinia species [19,23].…”