Probiotic bacteria and their bacteriocins to replace antibiotics in salmon aquaculture

根据联合国粮农组织的数据，全球有24个国家养殖鲑鱼，加拿大是仅次于挪威、智利和苏格兰的第四大生产国。最常见的三种是大西洋鲑鱼（Salmo salar）、奇努克鲑鱼（Oncorhynchus tshawytscha）和coho鲑鱼（Oncorhynchus kisutch）。加拿大是北美最大的养殖大西洋鲑鱼生产国（2011年产量为116,528公吨，估计价值为7.28亿美元）。在不列颠哥伦比亚省，受雇于孵化场、养鱼场和辅助活动的近6000人创造了8亿加元的收入。然而，养殖鲑鱼易患细菌性疾病和寄生海虱（Lepeophtheirus salmonis和Caligus种）。加拿大卫生部已经批准了4种抗生素来对抗鲑鱼的细菌感染（盐酸土霉素、氟苯尼考、磺胺嘧啶+甲氧苄啶和磺胺二甲氧嘧啶+奥美托林）。大约2.5%的鲑鱼饲料经过处理：这相当于2007年使用了21330公斤抗生素。甲维菌素苯甲酸酯（SLICE）是一种广泛用于治疗海虱的抗寄生虫药物。然而，这些物质可以在环境中（例如海底沉积物）以及鱼类组织中持续存在，并可能导致可传播给人类病原体的耐药性。细菌素是一种无毒的抗菌肽，来自生长在食物上的非致病性细菌，以及它们的生产细菌（益生菌），是鲑鱼中使用的抗生素的主要替代品。本申请申请资金用于研究使用益生菌及其细菌素来治疗养殖鲑鱼中的细菌和海虱感染。该项目是化学生物学、食品科学和水产养殖研究小组之间的合作项目。特别是，该项目将审查使用鱼鲛肉杆菌UAL307（经加拿大卫生部批准作为食品添加剂）以及其他革兰氏阳性和革兰氏阴性细菌来消除鲑鱼疾病。一些候选包括沙门氏菌（细菌性肾病）、沙门氏气单胞菌（真菌病）、鳗弧菌（弧菌病）和粘森氏菌（冬季溃疡）。将研究使用类芽孢杆菌和芽孢杆菌来消灭海虱。

Salmon are farmed in >24 countries, with Canada being the 4th largest producer after Norway, Chile & Scotland according to the UN Food & Agriculture Organization. The 3 most common species are Atlantic salmon (Salmo salar), chinook salmon (Oncorhynchus tshawytscha) and coho salmon (Oncorhynchus kisutch). Canada is the largest North American producer of farmed Atlantic salmon (116,528 metric tons with an estimated value of US $728 million in 2011). In British Columbia the >6000 people employed in hatcheries, fish farms and supporting activities generated >$800 million. However, farmed salmon are susceptible to bacterial disease and parasitic sea lice (Lepeophtheirus salmonis and Caligus species). Health Canada has approved 4 antibiotics to combat bacterial infections in salmon (oxytetracycline hydrochloride, florfenicol, sulfadiazine + trimethoprim, and sulfadimethoxine + ormetoprim). About 2.5% of salmon feed is treated: this corresponds to 21,330 kilograms of antibiotic used in 2007. Emamectin benzoate (SLICE) is an antiparasitic widely used to treat sea lice. However, these substances can persist in the environment (e.g. sea bed sediment) as well as in fish tissue, and can lead to drug resistance that can be transmitted to human pathogens. Bacteriocins, non-toxic antimicrobial peptides from non-pathogenic bacteria that grow on food, as well as their producing bacteria (probiotics), are prime candidates for replacement of antibiotics used in salmon. This application requests funding to examine use of probiotic bacteria and their bacteriocins to treat bacterial and sea lice infections in farmed salmon. The project is a collaboration between research groups in chemical biology, food science and aquaculture. In particular, the project will examine use of Carnobacterium piscicola UAL307 (approved by Health Canada as a food additive) as well as other species of both Gram positive and Gram negative bacteria to eliminate salmon diseases. Some candidates include Renibacterium salmoninarum (bacterial kidney disease), Aeromonas salmonicida (furunculosis), Vibrio anguillarum (vibriosis) and Moritella viscosa (winter ulcer). The use of Paenibacillus and Bacillus species to eliminate sea lice will be investigated.