Marine Biological Section, University of Copenhagen, Strandpromenaden 5, DK-3000, Helsingør, Denmark.
Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA.
Sci Rep. 2018 Jul 2;8(1):9973. doi: 10.1038/s41598-018-28326-9.
Prophages are known to encode important virulence factors in the human pathogen Vibrio cholerae. However, little is known about the occurrence and composition of prophage-encoded traits in environmental vibrios. A database of 5,674 prophage-like elements constructed from 1,874 Vibrio genome sequences, covering sixty-four species, revealed that prophage-like elements encoding possible properties such as virulence and antibiotic resistance are widely distributed among environmental vibrios, including strains classified as non-pathogenic. Moreover, we found that 45% of Vibrio species harbored a complete prophage-like element belonging to the Inoviridae family, which encode the zonula occludens toxin (Zot) previously described in the V. cholerae. Interestingly, these zot-encoding prophages were found in a variety of Vibrio strains covering both clinical and marine isolates, including strains from deep sea hydrothermal vents and deep subseafloor sediments. In addition, the observation that a spacer from the CRISPR locus in the marine fish pathogen V. anguillarum strain PF7 had 95% sequence identity with a zot gene from the Inoviridae prophage found in V. anguillarum strain PF4, suggests acquired resistance to inoviruses in this species. Altogether, our results contribute to the understanding of the role of prophages as drivers of evolution and virulence in the marine Vibrio bacteria.
噬菌体被认为在人类病原体霍乱弧菌中编码重要的毒力因子。然而，关于环境弧菌中噬菌体编码特征的发生和组成知之甚少。从 1874 个弧菌基因组序列构建的包含 5674 个噬菌体样元件的数据库，涵盖了 64 个物种，揭示了编码毒力和抗生素抗性等可能特性的噬菌体样元件广泛分布在环境弧菌中，包括被归类为非致病性的菌株。此外，我们发现 45%的弧菌物种携带有完整的噬菌体样元件，属于 Inoviridae 科，该科编码先前在霍乱弧菌中描述的紧密连接毒素 (Zot)。有趣的是，这些编码 Zot 的噬菌体存在于各种弧菌菌株中，包括临床和海洋分离株，包括来自深海热液喷口和深海海底沉积物的菌株。此外，观察到海洋鱼类病原体鳗弧菌 PF7 菌株 CRISPR 基因座中的一个间隔子与鳗弧菌 PF4 菌株中 Inoviridae 噬菌体的 zot 基因具有 95%的序列同一性，这表明该物种对 Inoviridae 病毒获得了抗性。总之，我们的研究结果有助于理解噬菌体在海洋弧菌进化和毒力中的作用。
