Experiment on bacterial resistance to phages and bacterial harm to eukaryotic hosts with bacteria of the genus Vibrio, temperate vibriophages and the pipefish Syngnathus typhle

Background: Evolutionary shifts in bacterial virulence are often associated with a third biological player, for instance temperate phages, that can act as hyperparasites. By integrating as prophages into the bacterial genome they can contribute accessory genes, which can enhance the fitness of their prokaryotic carrier (lysogenic conversion). Hyperparasitic influence in tripartite biotic interactions has so far been largely neglected in empirical host-parasite studies due to their inherent complexity. Here we experimentally address whether bacterial resistance to phages and bacterial harm to eukaryotic hosts is linked using a natural tri-partite system with bacteria of the genus Vibrio, temperate vibriophages and the pipefish Syngnathus typhle. We induced prophages from all bacterial isolates and constructed a three-fold replicated, fully reciprocal 75x75 phage-bacteria infection matrix. […]研究背景：细菌毒力的进化转变通常与第三种生物参与者相关，例如可充当重寄生物（hyperparasites）的温和噬菌体（temperate phages）。这类病毒以前噬菌体（prophages）的形式整合至细菌基因组后，可传递附属基因（accessory genes），进而提升其原核宿主的适合度（fitness），该过程即溶原性转换（lysogenic conversion）。由于三方生物相互作用（tripartite biotic interactions）存在固有复杂性，迄今为止，这类重寄生物在三方互作中的影响在实证宿主-寄生物研究中长期被大幅忽视。本研究依托由弧菌属（Vibrio）细菌、弧菌温和噬菌体以及尖海龙（Syngnathus typhle）构成的天然三方系统，通过实验探究细菌对噬菌体的抗性与细菌对真核宿主的致病危害之间是否存在关联。我们从所有细菌分离株（bacterial isolates）中诱导得到前噬菌体，并构建了三重重复、完全互作的75×75噬菌体-细菌感染矩阵（phage-bacteria infection matrix）。[…]