United States Department of Agriculture, Agricultural Research Service, Delaware State University, Dover, Delaware, USA
United States Department of Agriculture, Agricultural Research Service, Delaware State University, Dover, Delaware, USA.
Appl Environ Microbiol. 2021 Apr 27;87(10). doi: 10.1128/AEM.00008-21.
and are pathogens responsible for high larval oyster mortality rates in shellfish hatcheries. Bacteriophage therapy was evaluated to determine its potential to remediate these mortalities. Sixteen phages against and were isolated and characterized from Hawaiian seawater. Fourteen isolates were members of the family, and two were members of the In proof-of-principle trials, a cocktail of five phages reduced mortalities of larval Eastern oysters () and Pacific oysters () by up to 91% 6 days after challenge with lethal doses of Larval survival depended on the oyster species, the quantities of phages and vibrios applied, and the species and strain of A later-generation cocktail, designated VCP300, was formulated with three lytic phages subsequently named phages vB_VcorM-GR7B, vB_VcorM-GR11A, and vB_VcorM-GR28A (abbreviated 7B, 11A, and 28A, respectively). Together, these three phages displayed host specificity toward eight strains and a strain. Larval mortalities from strains RE98 and OCN008 were significantly reduced by >90% (< 0.0001) over 6 days with phage treatment compared to those of untreated controls. Genomic sequencing of phages 7B, 11A, and 28A revealed 207,758-, 194,800-, and 154,046-bp linear DNA genomes, respectively, with the latter showing 92% similarity to phage YC, a strain from the Great Barrier Reef, Australia. Phage 7B and 11A genomes showed little similarity to phages in the NCBI database. This study demonstrates the promising potential for phage therapy to reduce larval oyster mortalities in oyster hatcheries. Shellfish hatcheries encounter episodic outbreaks of larval oyster mortalities, jeopardizing the economic stability of hatcheries and the commercial shellfish industry. Shellfish pathogens like and have been recognized as major contributors of larval oyster mortalities in U.S. East and West Coast hatcheries for many years. This study isolated, identified, and characterized bacteriophages against these species and demonstrated their ability to reduce mortalities from in larval Pacific oysters and from both and in larval Eastern oysters. Phage therapy offers a promising approach for stimulating hatchery production to ensure the well-being of hatcheries and the commercial oyster trade.
和 是贝类孵化场中导致幼虫牡蛎高死亡率的病原体。评估了噬菌体疗法以确定其修复这些死亡率的潜力。从夏威夷海水中分离并鉴定了 16 种针对 和 的噬菌体。14 个分离物是 科的成员，2 个是 科的成员。在原理验证试验中，鸡尾酒中的五种噬菌体可将幼虫东方牡蛎（）和太平洋牡蛎（）的死亡率降低高达 91%，在受到致命剂量的挑战后 6 天。幼虫的存活率取决于牡蛎物种、噬菌体和弧菌的用量以及 的物种和菌株。后来的一代鸡尾酒，命名为 VCP300，由三种溶菌噬菌体组成，随后分别命名为 vB_VcorM-GR7B、vB_VcorM-GR11A 和 vB_VcorM-GR28A（分别简称 7B、11A 和 28A）。这三种噬菌体共同显示出对八个 菌株和一个 菌株的宿主特异性。与未处理的对照组相比，噬菌体处理可使菌株 RE98 和 OCN008 的幼虫 死亡率在 6 天内显著降低 >90%（<0.0001）。噬菌体 7B、11A 和 28A 的基因组测序分别显示出 207,758、194,800 和 154,046bp 的线性 DNA 基因组，后一种与来自澳大利亚大堡礁的菌株 YC 噬菌体具有 92%的相似性。噬菌体 7B 和 11A 基因组与 NCBI 数据库中的噬菌体几乎没有相似性。这项研究证明了噬菌体疗法在减少贝类孵化场幼虫牡蛎死亡率方面具有广阔的应用前景。贝类孵化场会不时爆发幼虫牡蛎死亡率，这危及孵化场的经济稳定和商业贝类产业。多年来，和 等贝类病原体已被认为是美国东海岸和西海岸孵化场幼虫牡蛎死亡率的主要原因。本研究分离、鉴定并鉴定了针对这些 物种的噬菌体，并证明了它们降低幼虫太平洋牡蛎和幼虫东方牡蛎中 死亡率的能力。噬菌体疗法为刺激孵化场生产提供了一种有前途的方法，以确保孵化场和商业牡蛎贸易的健康发展。
