文章摘要
无乳链球菌GD201008-001二元调控系统RscSR的鉴定及其对细菌应激适应性和毒力特性的影响
Identification of two-component system RscSR in Streptococcus agalactiae GD201008-001 reveals its influence on the stress response and virulence
投稿时间:2020-10-13  修订日期:2020-12-30
DOI:
中文关键词: 无乳链球菌  二元调控系统  耐酸应激  耐氧化应激  巨噬细胞  毒力
英文关键词: Streptococcus agalactiae  two-component system  acid tolerance  oxidative stress tolerance  macrophages  virulence
基金项目:江苏省自然基金项目(BK20171376);江苏高校优势学科建设工程项目(PAPD)
作者单位邮编
聂蒙 南京农业大学动物医学院 210095
马可 南京农业大学动物医学院 
曹青 南京农业大学动物医学院 
黄昊 南京农业大学动物医学院 
姬姝婷 南京农业大学动物医学院 
刘永杰 南京农业大学动物医学院 210095
摘要点击次数: 166
全文下载次数: 0
中文摘要:
      针对鱼源无乳链球菌GD201008-001,利用生物信息学方法预测到可能的二元调控系统(two-component system, TCS)RscSR,对其组成成分RscS和RscR的三维结构和保守结构域进行分析;构建基因缺失株ΔrscSR与互补株CΔrscSR,测定细菌的生长曲线,检测其耐酸应激、耐氧化应激、抗巨噬细胞吞噬和胞内存活能力,同时测定其对巨噬细胞的毒性和对小鼠的毒力。结果显示:RscSR具有典型的TCS结构特点,其中RscS具有组氨酸激酶结构域,RscR具有反应调节子结构;其编码基因缺失后,菌株耐酸、耐氧化、抗巨噬细胞吞噬和胞内存活能力及对巨噬细胞毒性均显著降低,而将该基因回补后各项能力均有所恢复;动物试验表明,野生株感染小鼠19h内全部死亡,而RscSR缺失株感染小鼠全部死亡时间为48h。研究表明,RscSR在无乳链球菌应激适应性以及毒力方面发挥重要作用,为深入探究该菌致病机制奠定基础。
英文摘要:
      A putative two-component system (TCS) RscSR was predicted in piscine Streptococcus agalactiae GD201008-001 using bioinformatics methods, and the three-dimensional structure and conserved domains of its constituent components RscS and RscR were analyzed. The rscSR deletion mutant stain ΔrscSR was constructed using homologous recombination. The corresponding gene-complemented strain CΔrscSR was also constructed. The growth curve of bacteria was measured in GD201008-001, ΔrscSR and CΔrscSR strain. Acid tolerance ability, oxidative stress tolerance ability, anti-phagocytosis ability and intracellular survival ability were detected, and cytotoxicity to macrophages and pathogenicity in mice were investigated as well. RscS and RscR are predicted to be a typical histidine kinase and response regulator, respectively. The inactivation of rscSR caused a substantial decrease in all of the above-mentioned indexes in S. agalactiae, and it was restored after complementing the gene. The mice pathogenicity testing showed that mice infected with the wild strain all died within 19 hours, while mice infected the rscSR deletion strain all died within 48 hours. This study suggests RscSR plays an important role in stress response and virulence of S. agalactiae, which will provide useful information for further exploration of pathogenic mechanism of this bacterium.
HTML     下载PDF阅读器
关闭

手机扫一扫看