Objective: To analyze the function of htpG of S. flexneri 2a 2457T, we constructed an htpG deletion mutant and a recovery mutant.
Methods: gamma-Red recombination system was used to construct an htpG deletion mutant of S. flexneri 2a 2457T. In addition, a recover mutant was obtained by introducing a low-copy plasmid containing one copy of htpG gene into the deletion mutant. Then, the growth curves of wild-type strain, deletion mutant and recover mutant were measured. Some of biochemical tests were also investigated. Furthermore, the Sereny tests were performed to evaluate the virulence of these strains.
Results: No significant difference were observed among three strains. However, the titers of some inflammatory factors evoked by wild-type strain, deletion mutant and recovery mutant in intraperitoneal injected mice were quite different.
Conclusion: These results suggest that the HtpG protein of Shigella flexneri 2a strain 2457T might be involved in the immunopathogenesis.