杀鱼假交替单胞菌2515的抗弧菌效果及在对虾养殖中的应用

为探讨一株杀鱼假交替单胞菌2515 Pseudoalteromonas piscicida(简称菌株2515)在对虾养殖中的抗弧菌效果,以鳗弧菌(Vibrio anguillarum)为指示菌,以鳗弧菌的敏感抗生素新霉素为参比,采用牛津杯打孔法,比较了菌株2515与抗生素抗菌等效关系.设置浓度分别为104 CFU/mL...

Anti-vibrio effect of Pseudoalteromonas piscicida 2515 and its applica-tion in shrimp culture

Acute hepatopancreatic necrosis disease caused by Vibrio has brought huge economic losses to the shrimp farming industry in many countries. Owing to restrictions on the application of antibiotics in aquaculture and the demand for green and healthy aquatic products in the market, microbial control technology has shown great application prospects in the prevention and control of shrimp diseases. Pseudoalteromonas piscicida 2515 (strain 2515) is a broad-spectrum Vibrio antagonistic bacterium that has probiotic potential in aquaculture. To investigate the antagonistic effect of strain 2515 against Vibrio in shrimp farming, the antimicrobial effect between strain 2515 and neomycin was compared using the Oxford cup test method, with V. anguillarum as the indicator. The antagonistic effect of V. anguillarum was evaluated by co-culture with strain 2515 at concentrations of 10⁴ CFU/mL, 10⁵ CFU/mL, 10⁶ CFU/mL, and 10⁷ CFU/mL. To study the application effect, the total number of bacteria and Vibrio in the aquaculture water and shrimp intestines were analyzed after strain 2515 was administrated by oral and immersion at concentrations of 10³ CFU/g, 10⁵ CFU/g, and 10⁷ CFU/g in the feed and 10³ CFU/mL, 10⁵ CFU/mL, and 10⁷ CFU/mL in the water body, respectively. The relative percent survival (RPS) against V. parahaemolyticus in each group was compared. The results showed a corresponding relationship between the number of strain 2515 and the quality of neomycin under the same effect as against V. anguillarum. Strain 2515 concentrations of 10⁶ CFU/mL and 10⁷ CFU/mL showed strong antibacterial effects when co-cultured with V. anguillarum. Strain 2515 concentrations of 10⁵ CFU/g and 10⁷ CFU/g in shrimp feed could significantly increase shrimp survival rate and reduced the number of Vibrio in shrimp intestines (P < 0.05). The optimum concentration was 10⁵ CFU/g, which exhibited the lowest mortality (43.3±5.8)% and the highest RPS (53.7±6.2)% against V. parahaemolyticus. The results indicated that strain 2515, added in feed or water in appropriate concentrations, could improve the ability of shrimp resistance to V. parahaemolyticus and reduce the number of Vibrio in shrimp intestines.