Pak J Biol Sci. 2020 Jan;23(12):1513-1522. doi: 10.3923/pjbs.2020.1513.1522.
Bacterial fish diseases constitute a major problem in aquaculture, it was found in the environment and under stressors cause severe economic losses to fish. This work aimed to investigate the bacterial causes and suitable treatments of mass mortality in some cultured marine fish farms in Damietta governorate.
The study was performed on 5 farms suffered from mass mortality. Total of 100 diseased fish (10 sea bass and 10 sea bream/farm) and 20 water samples were randomly collected from these farms. Bacteriological examinations were carried out followed by in vitro sensitivity tests. Treatment trial was performed using the most effective antibacterial agent on isolated bacteria.
From fish and water samples Pseudomonas spp., Aeromonas spp. and Vibrio spp. were isolated with the rat of (16, 10%), (22, 10%) and (28, 10%) respectively. These results were confirmed biochemically. Some virulence genes of isolated bacteria were detected using PCR; meanwhile, enrofloxacin reduced significantly the mortality rates in examined farms.
It could be concluded that, Pseudomonas spp., Aeromonas spp. and Vibrio spp. are the main bacterial species causing mass mortality in marine fish farms. These bacteria were highly sensitive to enrofloxacin in vitro and in vivo.
细菌鱼病是水产养殖中的一个主要问题，在环境中发现并在胁迫下会给鱼类造成严重的经济损失。本工作旨在调查导致达米埃塔省一些养殖海水鱼养殖场大规模死亡的细菌原因和合适的治疗方法。
本研究对 5 个遭受大规模死亡的养殖场进行了研究。从这些养殖场随机采集了 100 条患病鱼（10 条鲈鱼和 10 条鲷鱼/养殖场）和 20 个水样。进行了细菌学检查，随后进行了体外药敏试验。使用对分离细菌最有效的抗菌剂进行了治疗试验。
从鱼和水样中分离出了假单胞菌、气单胞菌和弧菌，其检出率分别为（16、10%）、（22、10%）和（28、10%）。这些结果通过生化方法得到了证实。使用 PCR 检测到了分离细菌的一些毒力基因；同时，恩诺沙星显著降低了检查养殖场的死亡率。
可以得出结论，假单胞菌、气单胞菌和弧菌是导致海水鱼养殖场大规模死亡的主要细菌种类。这些细菌在体外和体内对恩诺沙星高度敏感。
