Departamento de Biología Molecular, Área de Bioquímica y Biología Molecular, Universidad de León, Campus de Vegazana s/n, 24071 León, Spain.
FEMS Microbiol Lett. 2019 Apr 1;366(8). doi: 10.1093/femsle/fnz082.
The Rcs phosphorelay is a two-component signal transduction system that senses stressful environmental signals such as desiccation or low temperatures, which serve as natural inducers in bacteria. RcsA is an important coregulator in this system involved in some functions regulated by the Rcs system, including biofilm formation and capsule synthesis. In this sense, we previously showed that RcsA is necessary for colanic acid synthesis in Escherichia coli K92. Here, using an E. coli K92ΔrcsA mutant lacking rcsA gene we further characterize the implications of RcsA on E. coli K92 survival under osmotic and oxidative stressful conditions, and bacterial attachment and biofilm formation on both biotic and abiotic surfaces. Our results show that RcsA protects E. coli K92 against osmotic and, especially, oxidative stress at low temperatures. In addition, RcsA did not interfere in biofilm formation in any surface tested, including polystyrene, stainless steel, silicone, Teflon, aluminum and glass. By contrast, deletion of rcsA increased bacterial attachment to the caco-2 cells monolayer used as biotic surface.
Rcs 磷酸传递系统是一种双组分信号转导系统，可感知干燥或低温等应激环境信号，这些信号是细菌中的天然诱导物。RcsA 是该系统中的一个重要的共调节因子，参与 Rcs 系统调节的一些功能，包括生物膜形成和荚膜合成。在这个意义上，我们之前已经表明 RcsA 对于大肠杆菌 K92 的 colanic 酸合成是必需的。在这里，我们使用缺乏 rcsA 基因的大肠杆菌 K92ΔrcsA 突变体进一步研究了 RcsA 在大肠杆菌 K92 在渗透和氧化应激条件下生存、在生物和非生物表面上的细菌附着和生物膜形成中的影响。我们的结果表明，RcsA 可保护大肠杆菌 K92 免受低温下的渗透和特别是氧化应激。此外，RcsA 并未干扰在任何测试表面上的生物膜形成，包括聚苯乙烯、不锈钢、硅酮、特氟龙、铝和玻璃。相比之下，rcsA 的缺失增加了细菌对用作生物表面的 caco-2 细胞单层的附着。
