Abstract:
Interbacterial competition is known to shape the microbial communities found in the host, however the interplay between this competition and host defense are less clear. Here, we use the zebrafish hindbrain ventricle (HBV) as an in vivo platform to investigate host responses to defined bacterial communities with distinct forms of interbacterial competition. We found that antibacterial activity of the type VI secretion system (T6SS) from both Vibrio cholerae and Acinetobacter baylyi can induce host inflammation and sensitize the host to infection independent of any individual effector. Chemical suppression of inflammation could resolve T6SS-dependent differences in host survival, but the mechanism by which this occurred differed between the two bacterial species. By contrast, colicin-mediated antagonism elicited by an avirulent strain of Shigella sonnei induced a negligible host response despite being a more potent bacterial killer, resulting in no impact on A. baylyi or V. cholerae virulence. Altogether, these results provide insight into how different modes of interbacterial competition in vivo affect the host in distinct ways.
摘要:
已知细菌间竞争会塑造宿主中的微生物群落,然而,这场比赛和东道主防守之间的相互作用不太清楚。这里,我们使用斑马鱼后脑室(HBV)作为体内平台,研究宿主对具有不同形式的细菌间竞争的确定细菌群落的反应。我们发现,霍乱弧菌和鲍氏不动杆菌的VI型分泌系统(T6SS)的抗菌活性可诱导宿主炎症并使宿主对感染敏感,而与任何个体效应物无关。炎症的化学抑制可以解决宿主生存中T6SS依赖性的差异,但是两种细菌之间发生这种情况的机制有所不同。相比之下,尽管是更有效的细菌杀手,但由宋内志贺氏菌的无毒菌株引起的大肠杆菌素介导的拮抗作用却引起了可忽略的宿主反应,对Baylyi或霍乱弧菌毒力没有影响。总之,这些结果提供了有关体内细菌间竞争的不同模式如何以不同方式影响宿主的见解。