分子伴侣hfq基因缺失对单核细胞增生李斯特菌毒力及生物被膜生成的影响

为了解非编码RNA(non-coding RNA,ncRNA)分子伴侣蛋白Hfq在LM毒力中发挥的调控作用,在构建LM-Δhfq缺失株的基础上,通过动物攻毒试验检测野毒株LM-SB5与缺失株LM-Δhfq对昆明系小鼠的LD50,肝、脾载菌量及对肝、脾、肾的病理损伤;通过溶血试验检测二者的溶血活性;通过结晶紫染色的方法检测二者的生物被膜生成能力。以分析hfq基因缺失对LM毒力及生物被膜生成的影响。结果显示,与LM-SB5相比,LM-Δhfq对小鼠的LD50升高了6.067倍,毒力显著降低;肝、脾载菌量在第2,4,5天显著下降(P0.05),在第3天下降极显著(P0.01);对肝、脾、肾的病理损伤也有所减弱,LM-Δhfq较LM-SB5溶血能力下降了2倍,生物被膜生成能力在24 h时显著降低(P0.05)。研究结果证实,Hfq蛋白对LM的毒力及生物被膜生成能力具有重要调控作用。

Effect of Chaperone hfq Gene Deletion on Listeria monocytogenes Virulence and Biofilm Formation

To understand the impacts of non-coding RNA (ncRNA) chaprone Hfq protein on LM's virulence,we compared LM-△hfq with LM-SB5 in the following aspects:LD50to Kunming mouse,amount in mouse liver and spleen as well as effects on pathology of mouse liver,spleen and kidney after inoculation.Hemolysis activity was determined by hemolysis activity assay experiment.Biofilm was prepared and measured to compare the capability of biofilm formation by using crystal violet staining.The results showed that LD50 of LM-Ahfq to Kunming mouse was increased by 6.067 times than that of LM-SBS,indicating strain LM-△hfq had significantly decreased virulence.LM-△hfq amount in liver and spleen was significantly lower than that of LM-SB5 in the days of 2,4,5 after infection and extremely significant lower in the days of 3 after infection;pathological damages of liver,spleen and kidney of mouse infected LM-△hfq was declined compared to that of LM-SB5 infection.Hemolysis activity of LM-△hfq decreased 2 times than that of LM-SB5.The amount of biofilm formed by LM-△hfq was attenuated.Taking together,the results indicated that ncRNA chaprone Hfq protein is crucial in regulating LM virulence and capability of biofilm formation.