Probiotic bacteria and their bacteriocins to replace antibiotics in salmon aquaculture

根据联合国粮农组织的数据，三文鱼在24个国家养殖，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3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大西洋养殖三文鱼生产国(2011年为116,528公吨，估计价值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6000人创造了8亿美元的收入。然而，养殖的鲑鱼容易感染细菌性疾病和寄生的海虱(鲑鱼和Caligus种)。加拿大卫生部已经批准了4种抗生素来对抗三文鱼中的细菌感染(盐酸土霉素、氟苯尼考、磺胺二甲嘧啶+甲氧苄啶和磺胺二甲氧嘧啶+奥美托普林)。大约2.5%的鲑鱼饲料经过处理：这相当于2007年使用的21,330公斤抗生素。阿维菌素苯甲酸酯(片剂)是一种广泛用于治疗海虱的抗寄生虫药。然而，这些物质可以在环境(如海底沉积物)和鱼类组织中持续存在，并可能导致耐药性，可传播给人类病原体。细菌素是生长在食品上的非致病细菌中的无毒抗菌肽，以及它们的产生菌(益生菌)，是三文鱼中使用的抗生素的主要替代品。这项申请要求提供资金，以检查益生菌及其细菌素在治疗养殖三文鱼中的细菌和海虱感染方面的使用。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。特别是，该项目将研究使用鱼肉杆菌UAL307(加拿大卫生部批准作为食品添加剂)以及其他种类的革兰氏阳性和革兰氏阴性细菌来消除鲑鱼疾病。一些候选细菌包括沙门氏菌(细菌性肾病)、沙门氏气单胞菌(真菌病)、鳗弧菌(弧菌病)和粘性Moritella(冬季溃疡)。将研究使用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.