低聚木糖下调鼠伤寒沙门氏菌STM0306基因表达并抑制其黏附能力的作用

Study on The Effect of Xylooligosaccharides in Down-Regulating The STM0306 Gene Expression and Inhibiting The Adhesion Ability of Salmonella typhimurium

试验旨在探究低聚木糖(xylooligosaccharides,XOS)对鼠伤寒沙门氏菌(Salmonella typhimurium,S.typhimurium)黏附素基因表达及黏附能力的影响,为畜禽养殖中缓解沙门氏菌的感染提供基础。以IPEC-J2细胞为模型,探究了XOS对鼠伤寒沙门氏菌黏附能力的影响和黏附素STM0306基因表达的调控效果及机制。结果表明,XOS显著降低了鼠伤寒沙门氏菌对IPEC-J2细胞的黏附能力(P<0.05);qRT-PCR结果表明,XOS处理导致鼠伤寒沙门氏菌黏附素基因STM0306表达量极显著降低(P<0.01);进一步研究发现,XOS处理后,鼠伤寒沙门氏菌培养基的pH显著降低(P<0.05),Mg^(2+)浓度显著提高(P<0.05)。说明,XOS可能通过调控菌液的Mg^(2+)浓度在一定程度上抑制鼠伤寒沙门氏菌PhoP/PhoQ调控系统,进而抑制其下游基因STM0306表达,从而降低细菌对IPEC-J2细胞的黏附能力。

The experiment aims to investigate the effect of xylooligosaccharides(XOS) on the expression of the adhesin gene of Salmonella typhimurium(S.typhimurium) and its adhesion ability to host cells,and to provide a basis for the mitigation of Salmonella infection in livestock and poultry farming.We investigated the effect of XOS on the adhesion of S.typhimurium to IPEC-J2 cells,and on the regulation mechanism of the expression of the STM0306 gene.The results showed that XOS reduced the adhesion ability of S.typhimurium to IPEC-J2 cells(P<0.05);qRT-PCR results showed that XOS treatment resulted in a reduction in the relative expression of S.typhimurium adhesin gene STM0306(P<0.01);further study revealed that the pH value of medium was reduced(P<0.05) and the Mg^(2+) concentration was increased(P<0.05) after XOS treatment.It indicated that XOS might inhibit the PhoP/PhoQ regulatory system of S.typhimurium by regulating the Mg^(2+) concentration of the bacterial solution,which in turn inhibits the expression of its downstream gene STM0306,thereby reducing the adhesion of S.typhimurium to IPEC-J2 cells.