Yersinia enerocolitica incidence of swine herds of Lithuania and their antimicrobial susceptibility

The aim of the present work was to determine the prevalence of pathogenic Yersinia enterocolitica bacteria in slaughtered pigs from Lithuanian pig farms using multiplex Polymerase Chain Reaction (PCR) method and to determine their antimicrobial resistance using 3 antimicrobial agents. A total of 105 microbiological samples (70 faecal samples and 35 carcass swab samples) were collected and examined from slaughtered pigs from seven different Lithuanian pig farms. Yersinia spp. bacteria were isolated using cold enrichment method (21days at 4ºC) in PMB broth with further planting on CIN agar. The results of our study showed that using multiplex PCR method pathogenic Yersinia spp. was found in slaughtered pig samples delivered from 6 of 7 (86%) different farms. Yersinia spp. were identified in 21 (30%) of faecal and in 7 (20%) of carcass swab samples respectively. Yersinia enterocolitica was more prevalent in faecal samples (19%) than in carcass swab samples (17%). All obtained isolates of Y. enterocolitica were identified as serotype O:3. Using the reference agar dilution method, susceptibility to three antimicrobial agents (tetracycline, ciprofloxacin and ampicilin) was tested. The strains showed high MIC levels to tetracycline and all obtained isolates of Y. enterocolitica were resistant to ampicilin. The highest susceptibility was found to ciprofloxacin. To our knowledge, no report of Yersinia spp. isolation and identification and antimicrobial susceptibility from slaughtered pigs from Lithuanian pig farms in Lithuania was made before. The results obtained in the present study could serve for future investigations of the Yersinia spp. infection