Cultured microalgae are the primary food source for oyster larvae during hatchery culture and are a potential vector for Vibrio spp. infection of larval cultures. Bacteriophages have shown potential for controlling contamination of Vibrio spp. in aquaculture systems and their application could be an effective biological control method to eliminate such bacterial contamination of microalgae. This study investigated whether Vibrio-free microalgae sources could be ensured via the application of Vibrio specific phages. As a first step, four different Vibrio bacteriophages (belonging to the Myoviridae viral family) were isolated from marine waters in Queensland, Australia and used in challenge tests against a Vibrio host species, previously isolated from New South Wales oyster hatchery and found to be closely related to V. alginolyticus (ATCC 17749). The genome sequence of one of the four isolated bacteriophages, Vibrio Φ-2, that displayed strongest virulence against the host was determined. The 242446 bp genome of this bacteriophage was predicted to encode 217 proteins with an average GC content of 43.91%, containing putative thymidine kinases and a lysin enzyme. Application of these bacteriophages to pathogenic Vibrio spp. contaminating microalgae suspensions resulted in significant decreases in their numbers within 2 h. Findings indicated that direct application of bacteriophages to microalgae suspensions could be an effective method of reducing the occurrence of vibriosis in oyster hatcheries.

中文翻译：

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使用噬菌体控制孵化养殖过程中用作牡蛎幼虫食物来源的微藻的弧菌污染

培养的微藻是孵化场培养过程中牡蛎幼虫的主要食物来源，并且是弧菌属的潜在载体。幼虫培养物的感染。噬菌体已显示出控制弧菌属污染的潜力。在水产养殖系统中及其应用可能是一种有效的生物控制方法，以消除微藻的这种细菌污染。该研究调查了是否可以通过应用弧菌特异性噬菌体来确保无弧菌的微藻来源。作为第一步，从澳大利亚昆士兰的海水中分离出四种不同的弧菌噬菌体（属于肌病毒科病毒科），并用于针对弧菌宿主物种的挑战测试，该物种之前从新南威尔士州牡蛎孵化场分离，发现与与溶藻弧菌 (ATCC 17749) 相关。确定了四种分离的噬菌体之一的基因组序列，弧菌 Φ-2，对宿主表现出最强的毒力。预计该噬菌体的 242446 bp 基因组编码 217 种蛋白质，平均 GC 含量为 43.91%，包含推定的胸苷激酶和溶素酶。这些噬菌体在致病性弧菌中的应用。污染微藻悬浮液导致其数量在 2 小时内显着减少。研究结果表明，将噬菌体直接应用于微藻悬浮液可能是减少牡蛎孵化场弧菌病发生的有效方法。预计该噬菌体的 242446 bp 基因组编码 217 种蛋白质，平均 GC 含量为 43.91%，包含推定的胸苷激酶和溶素酶。这些噬菌体在致病性弧菌中的应用。污染微藻悬浮液导致其数量在 2 小时内显着减少。研究结果表明，将噬菌体直接应用于微藻悬浮液可能是减少牡蛎孵化场弧菌病发生的有效方法。预计该噬菌体的 242446 bp 基因组编码 217 种蛋白质，平均 GC 含量为 43.91%，包含推定的胸苷激酶和溶素酶。这些噬菌体在致病性弧菌中的应用。污染微藻悬浮液导致其数量在 2 小时内显着减少。研究结果表明，将噬菌体直接应用于微藻悬浮液可能是减少牡蛎孵化场弧菌病发生的有效方法。