Abstract：Objective：To investigate the influence of OxyR on the survival of Salmonella enterica serovar Typhi (S.Typhi) under stress conditions. Methods: The oxyR deleted mutant of S.Typhi was prepared by the λ-Red recombination system; the oxyR complementary strain and the control strain were constructed by transferring the recombinant plasmid pBAD-oxyR and the empty vector pBAD/g Ⅲ into the oxyR deleted mutant, respectively. Growth curves of the wild type, oxyR deleted mutant, oxyR complementary and control strains were performed to observe the growth of S.Typhi in different stress conditions. Quantitative realtime polymerase chain reaction(qRT-PCR) analysis was used to examine the influence of OxyR on oxidative stress-related genes in S.Typhi. Results: The oxyR deleted mutant, the oxyR complementary and the control strain of S.Typhi were constructed successfully. The results of growth curves revealed that under oxidative stress, the growth of oxyR deleted mutant was significantly slower compared with the wild type(P<0.05) ; and the ability was restored in the oxyR complementary strain. qRT-PCR results demonstrated OxyR could repress the expression of hemH, but activate uxuA, which were regulated by OxyR. Conclusion: OxyR was involved in the resistance of S.Typhi to oxidative stress, which laid a foundation for further research on S.Typhi virulence.
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2013, Vol. 23 
