鳗鲡嗜水气单胞菌分离及其感染防治

Isolation and infection prevention of Aeromonas hydrophila from eels

从发病的养殖水样及鳗鲡体表溃烂处组织分离出一株M-1菌株,经16S r RNA测序鉴定为嗜水气单胞菌。对该菌进行溶血性、药物敏感性试验,结果表明:该菌株具有溶血性,并对链霉素、庆大霉素表现敏感,而对四环素、青霉素G、左氟沙星、诺氟沙星等6种抗生素表现出耐药性。在鳗鲡感染试验中,表现出具有较强的致病性,注射约107CFU/mL病原菌液0.5 mL,72 h内致死率达100%。在养殖防治模拟试验中,20%戊二醛溶液和10%聚维酮碘溶液的防治效果与庆大霉素接近,可大幅度杀灭水体中的嗜水气单胞菌,从而降低鳗鲡死亡率。从健康、绿色养殖长远角度来看,建议采用20%戊二醛溶液、10%聚维酮碘溶液不易导致增强耐药性的杀菌药物。

An M-1 strain was isolated from infected cultured water samples and the ulcerated tissue of eel,and was identified as Aeromonas hydrophila by 16S rRNA sequencing.The hemolytic and drug sensitivity of the bacteria were studied,the results showed that the strain was hemolytic and sensitive to streptomycin and gentamicin,but resistant to tetracycline,penicillin G,levofloxacin and norfloxacin.In the test of eel infection,it has shown strong pathogenicity,and the fatality rate reached 100%within 72 h after injection of 0.5 mL of the pathogen liquid with a concentration of 107 CFU/mL.In the simulation test of culture control,the control effect of 20%glutaraldehyde solution and 10%povidone iodine solution is close to that of gentamicin,which can kill Aeromonas hydrophila significantly and reduce the mortality of eel.However,from the perspective of health and green farming in the long run,it is recommended to use 20%glutaraldehyde solution and 10%povidone iodine solution that are not easy to increase drug resistance.