Quorum sensing negatively regulates chitinase in Vibrio harveyi
Quorum sensing negatively regulates chitinase in Vibrio harveyi
复制标题
DOI：
10.1111/j.1758-2229.2009.00043.x
复制
发表时间：
2010-02-01
影响因子：
3.3
通讯作者：
Bossier, Peter
中科院分区：
文献类型：
--
作者：
Defoirdt, Tom;Ruwandeepika, H. A. Darshanee;Bossier, Peter
群体感应是一种细菌细胞间的信息传递机制，调节哈维氏弧菌对不同宿主的毒力。几丁质酶可以被认为是一种毒力因子，因为它有助于病原菌附着在宿主上并穿透其组织（例如在虾的情况下）。在这里，我们表明，群体感应负调控几丁质酶在哈维氏弧菌。甲壳素对天然甲壳素从蟹壳，合成甲壳素衍生物甲壳素天青，和荧光甲壳素低聚物的几丁质分解活性显着较高的突变体中，其中群体感应系统是完全失活的突变体相比，该系统是最大限度地活跃。此外，添加含有信号分子的无细胞培养液降低了Harveyi Autoinducer 1和Autoinducer 2缺陷双突变体中的几丁质酶活性。最后，几丁质酶A的mRNA水平的突变体中，其中群体感应系统是最大的活性相比，该系统是完全失活的突变体低五倍。[2009年9月25日，在首次在线发表后添加了更正：前一句由“最后，与系统最大活性的突变体相比，群体感应系统完全失活的突变体中几丁质酶A mRNA水平低五倍。我们认为，这种调节可能有助于弧菌在宿主相关和自由生活的生活方式之间转换。
Quorum sensing, bacterial cell-to-cell communication, regulates the virulence of Vibrio harveyi towards different hosts. Chitinase can be considered as a virulence factor because it helps pathogenic bacteria to attach to the host and to penetrate its tissues (e.g. in case of shrimp). Here, we show that quorum sensing negatively regulates chitinase in V. harveyi. Chitinolytic activity towards natural chitin from crab shells, the synthetic chitin derivative chitin azure, and fluorogenic chitin oligomers was significantly higher in a mutant in which the quorum-sensing system is completely inactivated when compared with a mutant in which the system is maximally active. Furthermore, the addition of signal molecule containing cell-free culture fluids decreased chitinase activity in a Harveyi Autoinducer 1 and Autoinducer 2-deficient double mutant. Finally, chitinase A mRNA levels were fivefold lower in the mutant in which the quorum-sensing system is maximally active when compared with the mutant in which the system is completely inactivated. [Correction added on 25 September 2009, after first online publication: the preceding sentence was corrected from 'Finally, chitinase A mRNA levels were fivefold lower in the mutant in which the quorum-sensing system is completely inactivated when compared with the mutant in which the system is maximally active.'] We argue that this regulation might help the vibrios to switch between host-associated and free-living life styles.