Bacterial symbionts use a type VI secretion system to eliminate competitors in their natural host.
Bacterial symbionts use a type VI secretion system to eliminate competitors in their natural host.
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DOI：
10.1073/pnas.1808302115
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发表时间：
2018-09-04
影响因子：
11.1
通讯作者：
Septer AN
中科院分区：
文献类型：
--
作者：
Speare L;Cecere AG;Guckes KR;Smith S;Wollenberg MS;Mandel MJ;Miyashiro T;Septer AN
共生细菌之间的竞争可以改变微生物群落的结构和功能。然而，对影响这种相互作用的分子机制知之甚少。我们利用生物发光细菌和它们的鱿鱼宿主之间的联系来研究环境传播细菌如何竞争有限数量的宿主定植位点。我们的研究表明，费氏弧菌使用一种VI型分泌系统，作为一种依赖于接触的细菌间“武器”，在宿主体内消灭竞争菌株。这项工作阐明了一种机制，通过这种机制，菌株特异性差异驱动密切相关的细菌在建立有益的共生关系时参与致命的战斗，揭示了潜在殖民者之间的遗传变异如何直接影响宿主相关种群的空间结构。种内竞争描述了当同一物种的不同种群试图填补同一生态位时发生的负面相互作用。这种竞争预计会发生在宿主相关细菌之间，但在自然生物系统中进行研究一直具有挑战性。虽然海水中存在许多生物发光的费氏弧菌菌株，但只有少数菌株在野生捕获的乌贼个体的光器官隐窝中被发现，这表明在早期定植过程中可能存在种内竞争。利用基于培养的实验来研究不同费氏弧菌菌株之间的相互作用，我们发现“致死”和“非致死”分离株分别可以杀死或不杀死已被充分研究的光器官分离株ES114。这些致死菌株的杀伤表型需要一个编码在50 kb基因组岛中的VI型分泌系统（T6SS）。从野生捕获的成年鱿鱼的轻器官中可以培养出多个致死性和非致死性菌株。尽管致死菌株在体外消除了非致死菌株，但两种致死菌株可以在以依赖t6ss的方式形成的分散的微菌落中共存。这种共存在物理混合时不稳定，导致一种致命菌株不断消除另一种。当幼乌贼与致死性和非致死性菌株同时接种时，它们占据不同的隐窝，但当T6SS功能被破坏时，它们在隐窝内共存。这些研究结果结合了体外和动物宿主的自然分离和实验方法，揭示了T6SS在自然共生中建立宿主定植过程中对空间分离菌株的重要性。
Competition among cooccurring bacteria can change the structure and function of a microbial community. However, little is known about the molecular mechanisms that impact such interactions in vivo. We used the association between bioluminescent bacteria and their squid host to study how environmentally transmitted bacteria compete for a limited number of host colonization sites. Our work suggests that Vibrio fischeri use a type VI secretion system, acting as a contact-dependent interbacterial “weapon,” to eliminate competing strains from cooccupying sites in the host. This work illuminates a mechanism by which strain-specific differences drive closely related bacteria to engage in lethal battles as they establish a beneficial symbiosis, revealing how genetic variation among potential colonizers directly impacts the spatial structure of the host-associated population. Intraspecific competition describes the negative interaction that occurs when different populations of the same species attempt to fill the same niche. Such competition is predicted to occur among host-associated bacteria but has been challenging to study in natural biological systems. Although many bioluminescent Vibrio fischeri strains exist in seawater, only a few strains are found in the light-organ crypts of an individual wild-caught Euprymna scolopes squid, suggesting a possible role for intraspecific competition during early colonization. Using a culture-based assay to investigate the interactions of different V. fischeri strains, we found “lethal” and “nonlethal” isolates that could kill or not kill the well-studied light-organ isolate ES114, respectively. The killing phenotype of these lethal strains required a type VI secretion system (T6SS) encoded in a 50-kb genomic island. Multiple lethal and nonlethal strains could be cultured from the light organs of individual wild-caught adult squid. Although lethal strains eliminate nonlethal strains in vitro, two lethal strains could coexist in interspersed microcolonies that formed in a T6SS-dependent manner. This coexistence was destabilized upon physical mixing, resulting in one lethal strain consistently eliminating the other. When juvenile squid were coinoculated with lethal and nonlethal strains, they occupied different crypts, yet they were observed to coexist within crypts when T6SS function was disrupted. These findings, using a combination of natural isolates and experimental approaches in vitro and in the animal host, reveal the importance of T6SS in spatially separating strains during the establishment of host colonization in a natural symbiosis.
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影响因子：
6.7
作者：
Alteri CJ;Himpsl SD;Pickens SR;Lindner JR;Zora JS;Miller JE;Arno PD;Straight SW;Mobley HL
通讯作者：
Mobley HL
与痤疮相关的人皮肤微生物组中的痤疮丙酸杆菌菌株群体。
影响因子：
6.5
作者：
Fitz-Gibbon, Sorel;Tomida, Shuta;Chiu, Bor-Han;Lin Nguyen;Du, Christine;Liu, Minghsun;Elashoff, David;Erfe, Marie C.;Loncaric, Anya;Kim, Jenny;Modlin, Robert L.;Miller, Jeff F.;Sodergren, Erica;Craft, Noah;Weinstock, George M.;Li, Huiying
通讯作者：
Li, Huiying
影响因子：
6.4
作者：
Altindis E;Dong T;Catalano C;Mekalanos J
通讯作者：
Mekalanos J
影响因子：
3.7
作者：
Carruthers MD;Nicholson PA;Tracy EN;Munson RS Jr
通讯作者：
Munson RS Jr
DOI：
10.1098/rstb.2015.0021
发表时间：
2015-10-05
期刊：
Philosophical transactions of the Royal Society of London. Series B, Biological sciences
影响因子：
--
作者：
Basler M
通讯作者：
Basler M