A highly specific phage defense system is a conserved feature of the Vibrio cholerae mobilome
A highly specific phage defense system is a conserved feature of the Vibrio cholerae mobilome
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DOI：
10.1371/journal.pgen.1006838
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发表时间：
2017-06-01
期刊：
影响因子：
4.5
通讯作者：
Seed, Kimberley D.
中科院分区：
文献类型：
--
作者：
O'Hara, Brendan J.;Barth, Zachary K.;Seed, Kimberley D.
霍乱弧菌特异性噬菌体是人类感染霍乱期间微生物群落的共同特征。噬菌体施加强大的选择压力，有利于噬菌体抗性菌株的扩增，而不是它们脆弱的对应物。允许有毒霍乱弧菌菌株防御掠夺性噬菌体无处不在的威胁的机制尚未建立。在这里，我们表明，霍乱弧菌PLEs（噬菌体诱导的染色体岛样元件）是广泛分布的基因组岛致力于噬菌体防御。对跨越60年收集期的霍乱弧菌分离株的分析确定了5种独特的PLEs。值得注意的是，我们发现所有的PLEs（无论地理或时间来源）都对一种名为ICP1的肌病毒的感染有反应，这是在孟加拉国霍乱患者粪便样本中发现的最突出的霍乱弧菌噬菌体。我们发现PLE活性降低了噬菌体基因组复制，并加速了ICP1感染后的细胞裂解，杀死了感染的宿主细胞，并阻止了子代噬菌体的产生。PLEs被ICP1感染动员，并且可以扩散到邻近细胞，使得可以水平地获得免受噬菌体捕食的保护。我们的研究结果表明，PLEs是霍乱弧菌活动组的一个持久特征，它适合于提供保护，免受单一捕食性噬菌体的侵害，并促进了我们对细菌如何影响病原体进化的理解。
Vibrio cholerae-specific bacteriophages are common features of the microbial community during cholera infection in humans. Phages impose strong selective pressure that favors the expansion of phage-resistant strains over their vulnerable counterparts. The mechanisms allowing virulent V. cholerae strains to defend against the ubiquitous threat of predatory phages have not been established. Here, we show that V. cholerae PLEs (phage-inducible chromosomal island-like elements) are widespread genomic islands dedicated to phage defense. Analysis of V. cholerae isolates spanning a 60-year collection period identified five unique PLEs. Remarkably, we found that all PLEs (regardless of geographic or temporal origin) respond to infection by a myovirus called ICP1, the most prominent V. cholerae phage found in cholera patient stool samples from Bangladesh. We found that PLE activity reduces phage genome replication and accelerates cell lysis following ICP1 infection, killing infected host cells and preventing the production of progeny phage. PLEs are mobilized by ICP1 infection and can spread to neighboring cells such that protection from phage predation can be horizontally acquired. Our results reveal that PLEs are a persistent feature of the V. cholerae mobilome that are adapted to providing protection from a single predatory phage and advance our understanding of how phages influence pathogen evolution.