Avendaño-Herrera Ruben, Tapia-Cammas Diana, Duchaud Eric, Irgang Rute
Universidad Andrés Bello, Laboratorio de Patología de Organismos Acuáticosy Biotecnología Acuícolas, Facultad de Ciencias de la Vida, Viña del Mar, Chile.
Interdisciplinary Center for Aquaculture Research (INCAR), Viña del Mar, Chile.
J Fish Dis. 2020 Aug;43(8):877-888. doi: 10.1111/jfd.13199. Epub 2020 Jun 21.
Chile is currently the second largest producer of farmed salmon worldwide, but Flavobacterium psychrophilum, as one of the most detrimental pathogens, is responsible for major losses during the freshwater culturing step in salmonid fish farms. An antigenic study conducted 10 years ago reported four serological groups using 20 F. psychrophilum Chilean strains. To reduce disease outbreaks and to develop vaccine candidates, antigenic knowledge needs to be regularly updated using a significant number of additional recent F. psychrophilum isolates. The present study aimed at investigating the serological diversity of 118 F. psychrophilum isolates collected between 2006 and 2018 from farmed Atlantic salmon (Salmo salar), rainbow trout (Oncorhynchus mykiss) and coho salmon (Oncorhynchus kisutch). The current study supports an expansion of the known antigenic groups in Chile from 4 to 14. However, the use of the slide-agglutination technique for serotyping is costly, is labour-intensive and requires significant technical expertise. Addressing these points, the mPCR-based procedure was a very useful tool for serotyping the collected Chilean F. psychrophilum isolates. This technique revealed the presence of diverse mPCR serotypes (i.e. types 0, 1, 2 and 4). Therefore, mPCR should be employed to select the bacterial strain(s) for vaccine development and to conduct follow-up, selective breeding or epidemiological surveillance in Chilean fish farms. Given the presented findings, changes to Chilean fish-farming practices are vital for ensuring the continued productivity and well-being of farmed salmonids.
智利目前是全球第二大养殖三文鱼生产国，但嗜冷黄杆菌作为最具危害性的病原体之一，在鲑鱼养殖场的淡水养殖阶段造成了重大损失。10年前进行的一项抗原研究报告称，利用20株智利嗜冷黄杆菌菌株确定了4个血清学组。为减少疾病爆发并开发候选疫苗，需要使用大量最新的嗜冷黄杆菌分离株定期更新抗原知识。本研究旨在调查2006年至2018年间从养殖的大西洋鲑（Salmo salar）、虹鳟（Oncorhynchus mykiss）和银大麻哈鱼（Oncorhynchus kisutch）中收集的118株嗜冷黄杆菌分离株的血清学多样性。当前研究支持将智利已知的抗原组从4个扩展到14个。然而，使用玻片凝集技术进行血清分型成本高、劳动强度大且需要专业技术知识。针对这些问题，基于多重PCR的程序是对收集到的智利嗜冷黄杆菌分离株进行血清分型的非常有用的工具。该技术揭示了多种多重PCR血清型（即0型、1型、2型和4型）的存在。因此，在智利的养鱼场中，应采用多重PCR来选择用于疫苗开发的菌株，并进行后续的选育或流行病学监测。鉴于所呈现的研究结果，改变智利的养鱼方式对于确保养殖鲑鱼的持续生产力和健康至关重要。
