Distribution and molecular typing analysis of Yersinia enterocolitica in food in Wenzhou

Abstract

ObjectiveTo investigate the distribution and molecular typing characters of Yersinia enterocolitica in food in Wenzhou.MethodsAfter pre-enrichment of samples at 4 ℃， the selective media was used for the isolation and identification of Yersinia enterocolitica from food. The biotype， serotype， virulence genotype， drug resistance and pulsed field gel electrophoresis， （PFGE） molecular typing of the isolated strains were analyzed.ResultsAmong 676 samples in 6 categories， 69 Yersinia enterocolitica strains were isolated from 68 samples， with a positive rate of 10.1% （68/676）. The detection rate of prepared meat products was the highest （20.5%， 9/44）， followed by quick-frozen food （17.2%， 11/64）. Biotype 1A accounted for 95.7% （66/69） of the isolates， and the predominant bioserotype was 1A/O∶5 （29.0%）， followed by 1A/O∶8（14.5%）. 88.4% （61/69） of the strains only harbored ystB gene. Particularly， there was a bioserotype 4/O∶3 strain carried the virulence gene of ail， ystA， yadA and virF. The sensitivity rates of the isolates to 14 kinds of antibiotics were over 94%. Thirty two serotyped strains were divided into 29 PFGE patterns.ConclusionFood was contaminated by Yersinia enterocolitica to some degree in Wenzhou， and the pathogenic strain was detected. The antibiotic resistance rate of Yersinia enterocolitica was at a low level， and PFGE suggested highly genetic polymorphism.

Keywords

• yersinia enterocolitica
• serotype
• virulence gene
• drug resistance
• molecular typing