Molecular Epidemiology Analysis Of Yersinia Enterocolitica In China

Yersinia enterocolitica is a cosmopolitan zoonotic entero-pathogen,widely recovered from human beings,various kinds of animal,food and environment. To acquaint with the distribution characters of Y.enterocofitica in China,1295 strains isolated in different region of China during 1980-2008,which from diarrhea patients,livestock,poultry,wild animals,food and environment,were analyzed in epidemiological distribution,biochemical metabolism,virulence genes and PFGE subtyping.The results showed that the distribution of Y. enterocolitic in China had geographic multiplicity and host diversity.Serotypes of the isolated were various,but O:3 and O:9 were the only two serotypes of pathogenic strains.The geographic distribution of pathogenic isolates was significantly different where most of these strains were isolated from the cold northern areas whereas some serotype O:3 strains were recovered from the warm southern areas.Clustering of PFGE showed the patterns of the pathogenic strains isolated from diarrhea patients were identical compared to those from the animals in the same area;thus suggesting the human infection was coming from the animals.Swine were the most important host of human infection,and dogs of farmers' maybe both the important primary carrier of pathogenic Y.enterocofifica and a potential source for the human infection.To characterize the gene types of Y.enterocolitica and genetic relationship with Y.pseudotuberculosis and Y.pestis,the study also analyzed Yersinia strains by the method of MLST(Multilocus sequences typing).According to the results of MLST analysis,Y.enterocolitica and Y.pseudotuberculosis came into two distinct complex,while Y.pestis was a branch of Y.pseudotuberculosis.And Y.enterocolitica STs complex was divided into two clusters which were pathogenic and non-pathogenic strains respectively.Pathogenic strains clustered in limited STs and exhibited high serotyped clonality.However, non-pathogenic strains dispersed in diverse STs and showed no association in epidemiology.