Surface attachment induces Pseudomonas aeruginosa virulence
Surface attachment induces Pseudomonas aeruginosa virulence
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DOI：
10.1073/pnas.1415712111
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发表时间：
2014-11-25
影响因子：
11.1
通讯作者：
Gitai, Zemer
中科院分区：
文献类型：
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作者：
Siryaporn, Albert;Kuchma, Sherry L.;Gitai, Zemer
铜绿假单胞菌感染每一种类型的宿主，已部署多个毒力因子检查。先前的毒力调控研究主要集中在化学线索上，但铜绿假单胞菌也可能对机械线索作出反应。使用基于快速成像的毒力测定，我们证明了铜绿假单胞菌在附着于一系列化学不同表面时激活毒力，这表明这种细菌物种对其底物的机械特性有反应。表面激活的毒力需要群体感应，但激活群体感应不会诱导没有表面附着的毒力。通过表面激活毒力也需要表面暴露的蛋白PilY1，它具有与真核生物机械传感器同源的结构域。假定的PilY1机械感觉结构域的特异性突变足以在非表面附着的细胞中诱导毒力，这表明PilY1介导表面机械转导。只有当细胞既处于高密度又附着在两个宿主非特异性线索表面时才触发毒力，这解释了铜绿假单胞菌如何在保持广泛宿主特异性的同时精确调节毒力。
Pseudomonas aeruginosa infects every type of host that has been examined by deploying multiple virulence factors. Previous studies of virulence regulation have largely focused on chemical cues, but P. aeruginosa may also respond to mechanical cues. Using a rapid imaging-based virulence assay, we demonstrate that P. aeruginosa activates virulence in response to attachment to a range of chemically distinct surfaces, suggesting that this bacterial species responds to mechanical properties of its substrates. Surface-activated virulence requires quorum sensing, but activating quorum sensing does not induce virulence without surface attachment. The activation of virulence by surfaces also requires the surface-exposed protein PilY1, which has a domain homologous to a eukaryotic mechanosensor. Specific mutation of the putative PilY1 mechanosensory domain is sufficient to induce virulence in non-surface-attached cells, suggesting that PilY1 mediates surface mechanotransduction. Triggering virulence only when cells are both at high density and attached to a surface-two host-nonspecific cues-explains how P. aeruginosa precisely regulates virulence while maintaining broad host specificity.