Biological characteristics of rpoS gene deleted mutant in Salmonella typhi / 中华临床感染病杂志

ABSTRACT

Objective To investigate the biological characteristics of rpoS gene deleted mutation in Salmonella typhi under different stress conditions,so as to explore the target gene for the prevention and treament of Salmonella typhi infection.Methods rpoS gene deleted mutant of Salmonella typhi was prepared by homologious recombination.rpoS mutant and parental strains were incubated under iso-osmia and various stress conditionsacid stress(pH 4.2),high osmolarity stress(NaCl 300 mmol/L),bile stress (1.5 mmol/L sodiumdeoxycbolate)and oxidative stress(1 mmol/L H2O2).The growth curves were compared between mutant and parental strains under different incubation conditions(t test).Results rpoS gene deleted mutant of Salmonella typhi Was successfully generated.Compared with the parental strain,the survival ability of rpoS mutant was significantly compromised under the acid stress,high osmolarity stress and oxidative stress(t values at4 h were 12.864,3.594 and 12.979;t values at 14 h were6.497,3.039 and 10.440,P<0.05 or<0.01).Conclusion rpoS is important for Salmonella typhi to overcome the acid,high osmolarity and oxidative stresses,and it may be a target gene for the prevention and treatment of Salmonella typhi infection.