Brzostek Katarzyna, Raczkowska Adrianna, Zasada Aleksandra
Institute of Microbiology, Warsaw University, 02-096 Warsaw Miecznikowa 1, Poland.
FEMS Microbiol Lett. 2003 Nov 21;228(2):265-71. doi: 10.1016/S0378-1097(03)00779-1.
Various environmental signals control the expression of the virulence factors in pathogenic Yersinia enterocolitica strains. The role of the osmotic regulator OmpR protein in controlling the production of Yop proteins, virulence determinants in Y. enterocolitica O:9 (European type) has been studied. An ompR deletion mutant was constructed via allelic exchange with an ompR gene of Y. enterocolitica mutagenized in vitro by a reverse genetic polymerase chain reaction (PCR)-based strategy. The ompR mutant showed a reduced ability to survive under conditions of various environmental stresses in vitro. In particular, low pH stress resulted in increased cell mortality levels. Under conditions of high osmolarity, the wild strain's Yop protein production was reduced, whereas protein levels from the mutant strain remained constant regardless of osmolarity variance. In J774A.1 macrophage cell culture survival of the ompR mutant was decidedly lower than that of the wild-type strain, suggesting that the OmpR protein may play a significant role in protecting cells against intracellular conditions associated with macrophage phagocytosis.
多种环境信号控制致病性小肠结肠炎耶尔森菌菌株中毒力因子的表达。已对渗透调节因子OmpR蛋白在控制小肠结肠炎耶尔森菌O:9（欧洲型）中毒力决定因素Yop蛋白产生方面的作用进行了研究。通过基于反向遗传聚合酶链反应（PCR）策略在体外诱变的小肠结肠炎耶尔森菌ompR基因进行等位基因交换，构建了一个ompR缺失突变体。ompR突变体在体外各种环境应激条件下的存活能力降低。特别是，低pH应激导致细胞死亡率增加。在高渗透压条件下，野生菌株的Yop蛋白产量降低，而突变菌株的蛋白水平无论渗透压如何变化都保持恒定。在J774A.1巨噬细胞培养中，ompR突变体的存活率明显低于野生型菌株，这表明OmpR蛋白可能在保护细胞免受与巨噬细胞吞噬相关的细胞内环境影响方面发挥重要作用。
