The Biological Role of MutT in the Pathogenesis of the Zoonotic Pathogen Serotype 2

() is an important rising pathogen that causes serious diseases in humans and pigs. Although some putative virulence factors of have been identified, its pathogenic mechanisms are largely unclear. Here, we identified a putative virulence-associated factor MutT, which is unique to serotype 2 (SS2) virulent strains. To investigate the biological roles of MutT in the SS2 virulent strain ZY05719, the knockout mutant (Δ) was generated and used to explore the phenotypic and virulent variations between the parental and Δ strains. We found that the mutation significantly inhibited cell growth ability, shortened the chain length, and displayed a high susceptibility to HO-induced oxidative stress. Moreover, this study revealed that MutT induced the adhesion and invasion of SS2 to host cells. Deletion of increased microbial clearance in host tissues of the infected mice. Sequence alignment results suggested that was encoded in a strain-specific manner, in which the detection was strongly linked to bacterial pathogenicity. In both zebrafish and mice infection models, the virulence of Δ was largely reduced compared with that of ZY05719. Overall, this study provides compelling evidence that MutT is indispensable for the virulence of SS2 and highlights the biological role of MutT in bacteria pathogenesis during infection.