σ^(B)激活因子样Lmo1642缺失对单核细胞增生李斯特菌环境应激和生物被膜形成的影响  

Effects of Deletion ofσ^(B)Activator Factor-Like Lmo1642 on Environmental Stress and Biofilm Formation in Listeria monocytogenes

作　　者：张亚萍 李能秀 焦健[1] 季春辉[1] 王立霞 才学鹏[2] 孟庆玲[1] 乔军[1] ZHANG Yaping;LI Nengxiu;JIAO Jian;JI Chunhui;WANG Lixia;CAI Xuepeng;MENG Qingling;QIAO Jun(College of Animal Science and Technology,Shihezi University,Shihezi 832003,China;Lanzhou Veterinary Research Institute,CAAS,Lanzhou 730046,China)

机构地区：[1]石河子大学动物科学学院,石河子843002 [2]中国农业科学院兰州兽医研究所,兰州730046

出　　处：《中国动物传染病学报》2025年第1期1-8,共8页Chinese Journal of Animal Infectious Diseases

基　　金：国家自然科学基金(32160819,31360596)。

摘　　要：单核细胞增生李斯特菌(LM)是一种对外界环境具有广泛适应性的人兽共患革兰氏阳性菌,σ^(B)因子(sigma B)是LM最重要的应激调控因子。为探究σ^(B)激活因子样Lmo1642的生物学功能,本研究以国际标准菌株LM EGD-e基因组为模板,扩增lmo1642基因,并分析其分子特征;通过同源重组技术构建lmo1642基因缺失株LM-Δlmo1642及回补株LM-CΔlmo1642,比较其在不同胁迫环境下的生长情况及生物被膜(BF)形成能力的差异,并通过qPCR检测与环境应激和BF形成相关基因的转录水平。结果显示:Lmo1642蛋白含有STAS结构域,属于STAS蛋白家族;与LM EGD-e和LM-CΔlmo1642相比,LM-Δlmo1642在42℃、pH9.0、3.8%乙醇以及不同渗透压环境下的适应能力明显减弱(P<0.05),但对LM生物被膜形成能力没有显著的影响(P>0.05);qPCR显示与环境应激有关基因sigB、opuCC、betL、clpP的相对转录水平显著降低(P<0.05),而BF相关基因actA没有显著的变化(P>0.05),表明lmo1642基因对LM的环境应激适应能力发挥了重要的调控作用。本研究为进一步揭示lmo1642基因调控LM环境应激能力的分子机制提供了前期研究基础。Listeria monocytogenes(LM)is a zoonotic gram-positive bacterium that can survive in a wide range of external environment.Sigma B factor(σ^(B))is the most important stress regulator of LM.To understand the biological function ofσ^(B)activator factor-like Lmo1642,the lmo1642 gene was amplified by using the international standard strain LM EGD-e genome as a template and its molecular characteristics were analyzed in this study.The lmo1642 gene deletion strain LM-Δlmo1642 and its complementation strain LMCΔlmo1642 were constructed using homologous recombination technology,respectively,and the differences in growth and biofilm generation of these strains were determined under different stress environment.Moreover,the transcription levels of genes related to environmental stress and biofilm formation were measured by qPCR.The results showed that Lmo1642 protein contained the STAS domain and belonged to the STAS protein family.The adaptation of LM-Δlmo1642 to environmental stresses was significantly(P<0.05)reduced at 42℃,pH9.0,3.8%ethanol and different osmotic pressure when compared to LM EGD-e and LM-CΔlmo1642 but the biofilm formation ability of LM-Δlmo1642 was not significantly different(P>0.05).The qPCR showed a significant(P<0.05)decrease in the relative transcription level of sigB,opuCC,betL and clpP genes related to environmental stress rather other the actA genes related to biofilm(P>0.05).These results demonstrated that lmo1642 played an important role in regulating the adaptive capacity of LM to environmental stress and provided new insights into the molecular mechanism of lmo1642 regulating environmental stress in LM.

关 键 词：单核细胞增生李斯特菌 lmo1642 环境应激 生物被膜 

分 类 号：S852.61[农业科学—基础兽医学]