College of Animal Science and Technology, Shihezi University, Shihezi 832003, Xinjiang, China.
Arch Microbiol. 2013 Feb;195(2):113-20. doi: 10.1007/s00203-012-0855-5. Epub 2012 Nov 29.
SigmaB factor is an important regulatory factor for stress response in Gram-positive bacteria such as Listeria monocytogenes (L. monocytogenes), Staphylococcus aureus and Bacillus subtilis. However, the activity of SigmaB factor is regulated by RsbV factor. Currently, the functional studies of RsbV factor are mostly focused on non-pathogenic B. subtilis, but the roles of RsbV factor in pathogenic L. monocytogenes during the regulation of environmental stress and virulence are still unclear. In the study, a ∆RsbV mutant of L. monocytogenes was constructed to explore the regulatory role of RsbV in environmental stress and virulence. The environmental stress experiments indicated that the growth and survival capability of ∆RsbV mutant obviously decreased in stress of low temperature, osmotic pressure, alcohol and acid, compared with EGD strain. The macrophage infection experiment indicated that ∆RsbV mutant had weaker survival capability than EGD strain, and the expression of PrfA, actA, PlcA and LLO was down-regulated in infected cells. Animal inoculation experiments indicated that RsbV deletion significantly reduced the pathogenicity of L. monocytogenes. Our data demonstrate that, in addition to regulating tolerance under environmental stress conditions, RsbV also contributes to regulation of L. monocytogenes virulence.
σB 因子是革兰氏阳性菌（如李斯特菌、金黄色葡萄球菌和枯草芽孢杆菌）应激反应的重要调节因子。然而，σB 因子的活性受到 RsbV 因子的调节。目前，RsbV 因子的功能研究主要集中在非致病性枯草芽孢杆菌上，但 RsbV 因子在致病性李斯特菌调节环境应激和毒力方面的作用仍不清楚。本研究构建了李斯特菌的 ∆RsbV 突变株，以探讨 RsbV 在环境应激和毒力调节中的作用。环境应激实验表明，与 EGD 株相比，∆RsbV 突变株在低温、渗透压、酒精和酸应激下的生长和存活能力明显下降。巨噬细胞感染实验表明，∆RsbV 突变株在感染细胞中的生存能力比 EGD 株弱，PrfA、actA、PlcA 和 LLO 的表达下调。动物接种实验表明，RsbV 缺失显著降低了李斯特菌的致病性。我们的数据表明，除了调节环境应激条件下的耐受性外，RsbV 还参与调节李斯特菌的毒力。
