台湾泥鳅源维氏气单胞菌Zy01株的分离鉴定及药敏特性研究

【目的】从患病台湾泥鳅体内分离到一株优势菌Zy01,通过鉴定并筛选敏感药物,为台湾泥鳅维氏气单胞菌病的防控提供参考。【方法】从患病台湾泥鳅肌肉溃烂处分离细菌,经理化特性及16S rRNA基因序列分析对其进行鉴定,通过人工感染试验确定病原,并利用K-B法进行药敏分析。【结果】菌株Zy01为2015年11月引发台湾泥鳅疾病的病原菌,其对台湾泥鳅的LC50为2.0×10~6 CFU/m L。菌株Zy01理化特性与维氏气单胞菌(Aeromonas veronii)基本一致,16S rRNA基因序列与维氏气单胞菌相似性为99%,综合判断该病原菌为维氏气单胞菌。菌株Zy01对环丙沙星、头孢拉定、诺氟沙星、阿奇霉素及庆大霉素等10种抗生素高度敏感;对苯唑西林、青霉素、阿莫西林等9种抗生素不敏感。【结论】分离菌株Zy01对台湾泥鳅有致病性,养殖时可选用庆大霉素及新霉素等药物进行防控。

Isolation and identification of Aeromonas veronii strain Zy01 from Taiwan Loach and its antibiotic sensitivity

Objective] To determine the cause of death for Taiwan Loach and screen sensitive drugs, a dominant bacteria strain Zy01 was isolated from of sick Taiwan Loach. This study will provide reference for further prevention and treatment of Aeromomas veronii in Taiwan Loach. Methods] The pathogenic bacteria were isolated and purified from ulcerated muscle of Taiwan Loach. And the identification of phenotypic information of the strain Zy01 was conducted, including the biochemical identification and 16S rRNA gene sequence determination. The tests of artificial infection by using strain Zy01 to infect Taiwan Loach. Antimicrobial susceptibility test was conducted by K-B methods. Results] Strain Zy01 was the pathogens of Taiwan Loach, the LC50 of the isolated was counted to 2.0×106 cfu/mL. According to morphological and biochemical characteristics as well as the result of 16S rRNA gene sequence analysis, the isolated strain Zy01 was A. veronii. Strain Zy01 was susceptible to ciprofloxacin, norfloxacin, azithromycin and gentamicin and other 10 kinds of antibiotics. Meanwhile, it showed resistance to oxacillin, penicillin, amoxicillin and other 9 kinds of antibiotics. Conclusion] The isolated bacterial strain Zy01 was pathogenic to Taiwan Loach, and prevented by administering drugs such as gentamicin and neomycin in fisheries farming.