Monitoring and analysis of Yersinia enterocolitica in Ningxia area

Objective:To survey the epidemic situation of infectious diarrhea and complications,the distribution situation of host and the type and virulence characteristics of epidemic bacteria Yersinia enterocolitica in Ningxia area.Methods:The stool specimens of animals and patients with diarrhea and the cecal contents of wild mouse in natural foci of plague were collected and then Yersinia bacteria were cultured.The serotypes and virulence gene detection of positive strains were identified eventually.Results:56 strains of Yersinia enterocolitica were isolated from all samples.Pigs had the highest infection rate and the positive rate was 9.40%.No strain was isolated from the rest of samples.The serotypes of positive strains mainly concentrated in O:3,O:5,O:8 and O:9.The pathogenic serotype of Yersinia enterocolitica mainly was O:3,and the second place was O:9.Besides,the serotypes of nonpathogenic or weak pathogenic strains were O:5 and O:8.The virulence genes about ail,YstA,virF,Yada and YatB were detected for 56 clinical isolation strains.The strains with O:3 and O:9 serotype were positive for first four virulence genes.Conclusion:Yersinia popular in this province is mainly O: 3 serotype with pigs as the main hosts.O: 3 and O: 9 serotypes carry the four virulence genes as the pathogenic strains.