RpoS-dependent stress response and exoenzyme production in Vibrio vulnificus
RpoS-dependent stress response and exoenzyme production in Vibrio vulnificus
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DOI：
10.1128/aem.69.10.6114-6120.2003
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发表时间：
2003-10-01
影响因子：
4.4
通讯作者：
Oliver, JD
中科院分区：
文献类型：
--
作者：
Hülsmann, A;Rosche, TM;Oliver, JD
创伤弧菌是一种能够通过摄食和伤口感染迅速引起致命感染的河口细菌。像其他机会致病菌一样，创伤弧菌必须适应潜在的压力环境变化，同时在海水中自由生活，在牡蛎肠道定植，并感染人类和鳗鱼等不同宿主。为了开始了解创伤弧菌对这种应激的反应能力，我们检查了交替σ因子RpoS的作用，其在许多病原体的应激反应和毒力中是重要的。通过同源重组构建创伤弧菌C7184o的rpoS突变体。突变株表现出的能力下降，生存不同的环境压力，包括暴露于过氧化氢，高渗透压，和酸性条件。最显著的区别是突变体对过氧化氢的高度敏感性。白蛋白酶，酪蛋白酶，弹性蛋白酶活性在野生型中检测到，但在突变株中没有，和另外两个水解活性（胶原酶和明胶酶）减少的突变株相比，野生型。此外，rpoS突变体的运动性严重降低。总体而言，这些研究表明，创伤弧菌中的rpoS对于适应环境变化很重要，并可能在毒力中发挥作用。
Vibrio vulnificus is an estuarine bacterium capable of causing rapidly fatal-infections through both ingestion and wound infection. Like other opportunistic pathogens, V. vulnificus must adapt to potentially stressful environmental changes while living freely in seawater, upon colonization of the oyster gut, and upon infection of such diverse hosts as humans and eels. In order to begin to understand the ability of V. vulnificus to respond to such stresses, we examined the role of the alternate sigma factor RpoS, which is important in stress response and virulence in many pathogens. An rpoS mutant of V. vulnificus strain C7184o was constructed by homologous recombination. The mutant strain exhibited a decreased ability to survive diverse environmental stresses, including exposure to hydrogen peroxide, hyperosmolarity, and acidic conditions. The most striking difference was a high sensitivity of the mutant to hydrogen peroxide. Albuminase, caseinase, and elastase activity were detected in the wild type but not in the mutant strain, and an additional two hydrolytic activities (collagenase and gelatinase) were reduced in the mutant strain compared to the wild type. Additionally, the motility of the rpoS mutant was severely diminished. Overall, these studies suggest that rpoS in V. vulnificus is important for adaptation to environmental changes and may have a role in virulence.