Functional Identification and Genetic Analysis of O-Antigen Gene Clusters of Food-Borne Pathogen O:10 and Other Uncommon Serotypes, Further Revealing Their Virulence Profiles.

is a globally distributed food-borne gastrointestinal pathogen. The O-antigen variation-determined serotype is an important characteristic of , allowing intraspecies classification for diagnosis and epidemiology purposes. Among the 11 serotypes associated with human yersiniosis, O:3, O:5,27, O:8, and O:9 are the most prevalent, and their O-antigen gene clusters have been well defined. In addition to the O-antigen, several virulence factors are involved in infection and pathogenesis of strains, and these are closely related to their biotypes, reflecting pathogenic properties. In this study, we identified the O-AGC of a strain WL-21 of serotype O:10, and confirmed its functionality in O-antigen synthesis. Furthermore, we analyzed the putative O-AGCs of uncommon serotypes, and found that the O-AGCs of were divided into two genetic patterns: (1) O-AGC within the locus, possibly synthesizing the O-antigen via the Wzx/Wzy dependent pathway, and (2) O-AGC within the locus, very likely assembling the O-antigen via the ABC transporter dependent pathway. By screening the virulence genes against genomes from GenBank, we discovered that strains representing different serotypes were grouped according to different virulence gene profiles, indicating strong links between serotypes and virulence markers and implying an interaction between them and the synergistic effect in pathogenicity. Our study provides a framework for further research on the origin and evolution of O-AGCs from , as well as on differences in virulent mechanisms among distinct serotypes.