sRNA GcvB对鼠伤寒沙门菌毒力的调控作用研究OA北大核心CSTPCD

Small RNAs(sRNAs)are a kind of regulatory molecules that can modulate gene expression at the post-transcriptional level,thereby after the physiological characteristics of bacteria.To investigate the regulatory role of the sRNA GcvB in the virulence of Salmonella typhimurium,in this study,we constructed mutant,complementary and tracer strains of GcvB gene to detect the effects on the ability of biofilm formation and swimming of Salmonella typhimurium.We also analyzed the differences in virulence and infection kinetics between parental strains and deletion strains,predicted and analyzed the potential target genes regulated by GcvB,and explored the role of GcvB in the regulation of the biofilm,oxidative stress and virulence of ST.The results showed that compared with the parental strain and the complementary strain,GcvB deletion increased the biofilm formation ability,significantly enhanced the resistance to oxidative stress,and increased the LD50 to 3.98-fold.Quantitative real-time PCR(qRT-PCR)analysis of the target genes,gcvA,bapA,hilA,igaA and sitD,showed that the expression of gcvA,bapA,igaA,and sitD was up-regulated in the transcriptional level,while the expression of hilA was decreased.The present study confirmed the involvement of sRNA GcvB in Salmonella typhimurium biofilm formation,oxidative stress and virulence,and provided a basis for preliminary studies on the regulatory mechanism of sRNA GcvB in ST biofilm,oxidative stress and virulence.