This study proposed that phage-enriched artemia could be a useful tool for transferring phage into the cultured fish (larvae or adult) as a feed, and introduce mode of phage administration and its safety in concern of tissue adaptation for efficient phage therapy in aquatic animals. First, whether Edwardsiella tarda phage (ETP-1) could attach or ingest by the artemia and optimum time period for the ETP-1 enrichment with artemia were investigated. ETP-1 dispersion, abundance and persistency, and zebrafish immune transcriptional responses and histopathology were evaluated after feeding the fish with ETP-1-enriched artemia. Hatched artemia nauplii (36 h) were enriched with 1.90 × 1011 PFUmL-1 of ETP-1, and maintained at 25 °C. The highest enrichment level was obtained after 4 h (3.00 × 109 PFUmL-1), and artemia were alive and active similar to control for 8 h. ETP-1 disseminated dose dependently to all the tissues rapidly (12 h). However, when feeding discontinued, it drastically decreased at day 3 with high abundance and persistency in the spleen (1.02 × 103) followed by the kidney (4.00 × 101) and the gut (1 × 101 PFUmL-1) for highest ETP-1-enriched artemia dose. In contrast, during continuous delivery of ETP-1-enriched artemia, ETP-1 detected in all the tissues (at day 10: gut; 1.90 × 107, kidney; 3.33 × 106, spleen; 5.52 × 105, liver; 6.20 × 104 PFUmL-1mg-1 tissues). Though the phage abundance varied, results indicated that oral fed ETP-1-enriched artemia disperse to the neighboring organs, even the absence of host as phage carrier. Non-significant differences of immune transcriptional and histopathology analysis between ETP-1-enriched artemia fed and controls suggest that no adverse apparent immune stimulation in host occurred, and use of ETP-1 at 1011 PFUmL-1 was safe. With further supportive studies, live artemia-mediated phage delivery method could be used as a promising tool during phage therapy against pathogenic bacteria to control aquatic diseases.

中文翻译：

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通过迟发性爱德华氏菌噬菌体 (ETP-1) 对卤虫无节幼体进行生物封装来开发噬菌体递送

该研究提出，富集噬菌体的卤虫可以作为一种有用的工具将噬菌体作为饲料转移到养殖鱼（幼虫或成虫）中，并引入噬菌体给药模式及其安全性，关注组织适应，以实现水生动物的有效噬菌体治疗. 首先，研究了迟发性爱德华氏菌噬菌体（ETP-1）是否可以通过卤虫附着或摄取，以及用卤虫富集 ETP-1 的最佳时间段。在用富含 ETP-1 的卤虫喂养鱼后，对 ETP-1 的分散、丰度和持久性以及斑马鱼的免疫转录反应和组织病理学进行了评估。孵化的卤虫无节幼体（36 小时）富含 1.90 × 1011 PFUmL-1 的 ETP-1，并保持在 25 °C。4 小时后获得最高富集水平（3.00 × 109 PFUmL-1），和卤虫在 8 小时内存活并活跃，与对照相似。ETP-1 迅速（12 小时）以剂量依赖性方式传播到所有组织。然而，当停止喂食时，它在第 3 天急剧下降，脾脏 (1.02 × 103) 丰度高且持久，其次是肾脏 (4.00 × 101) 和肠道 (1 × 101 PFUmL-1)，ETP-1 最高- 丰富的卤虫剂量。相比之下，在持续输送富含 ETP-1 的卤虫期间，在所有组织中检测到 ETP-1（第 10 天：肠道；1.90 × 107，肾；3.33 × 106，脾；5.52 × 105，肝；6.20 × 104 PFUmL-1mg-1 组织）。尽管噬菌体丰度各不相同，但结果表明，即使没有宿主作为噬菌体载体，口服富含 ETP-1 的卤虫也会分散到邻近器官。饲喂富含 ETP-1 的卤虫和对照组之间免疫转录和组织病理学分析的非显着差异表明宿主中没有发生不利的明显免疫刺激，并且使用 1011 PFUmL-1 的 ETP-1 是安全的。随着进一步的支持性研究，活卤虫介导的噬菌体递送方法可作为噬菌体治疗病原菌以控制水生疾病的有前景的工具。