Prevalence, characterization and antimicrobial susceptibility of Yersinia enterocolitica and other Yersinia species found in fruits and vegetables from the European Union

A total of 312 samples of fruits, vegetables and sprouts originating from the European Union states were examined for the presence of pathogenic and non-pathogenic Yersinia enterocolitica and other Yersinia spp. The samples were examined separately using both cultivation method and real-time quantitative PCR (qPCR) without pre-enrichment. The prevalence of Yersinia spp. in examined samples assessed by cultivation was 17.0% (53/312), with Y. enterocolitica and other Yersinia spp. comprising 5.8% (18/312) and 11.2% (35/312) of samples, respectively. The ail gene, which is associated with Y. enterocolitica pathogenicity, was detected only in one isolate (0.3%). Biotyping of isolates revealed only biotype 1A. Serotyping tests showed that four isolates belonged to serotype O:8 and one to serotype O:5. QPCR results confirmed the presence of Yersinia spp. and pathogenic Y. enterocolitica (carrying the ail gene) in 37 (11.9%) and 21 (6.7%) samples, respectively. Further, the susceptibility of Y. enterocolitica and the other Yersinia spp. isolates was tested using the agar dilution method and the Vitek® 2 system. All samples were susceptible to ciprofloxacin, gentamicin, enrofloxacin, cefotaxime, imipenem, meropenem, tobramycin, ciprofloxacin, colistin, trimethoprim and trimethoprim/sulfamethoxazole. The most commonly found resistance was to ampicillin (100%), followed by erythromycin (98.1%), amoxicillin/clavulanic acid (75.5%) and streptomycin (39.6%).