鳜源致病性维氏气单胞菌的鉴定及药敏试验

【目的】通过对从患病的鳜(Siniperca chuatsi)肝脏中分离得到的一株优势菌WJ2014-1进行鉴定,旨在确定病因并筛选出敏感药物,为今后鳜维氏气单胞菌(Aeromonas veronii)的防治提供参考。【方法】从患病鳜肝脏分离致病菌,通过对其生理生化特征与16S r RNA基因序列分析进行鉴定,并通过纸片扩散法进行药敏试验。【结果】用菌株WJ2014-1进行人工回归感染试验后,鳜发病症状与自然发病症状相似。根据该菌株的形态特征、生化特性、16S r RNA基因序列分析结果鉴定为维氏气单胞菌。该菌株对复方新诺明、强力霉素、罗红霉素、头孢噻肟、哌拉西林等21种抗生素敏感,对氯霉素、诺氟沙星、萘啶酸等9种抗生素耐药。【结论】分离得到的菌株WJ2014-1对鳜有致病性,生产中可选用复方新诺明、强力霉素、罗红霉素等药物进行防治。

Identification and susceptibility test of pathogenic Aeromonas veronii isolated from Siniperca chuatsi

Objective] To determine the cause of death for Siniperca chuatsi and screen sensitive drugs, a dominant bacteria WJ2014-1 was isolated from the liver of sick S. chuatsi. This study will provide reference for further prevention and treatment of Aeromomas veronii in S. chuatsi. Methods] The pathogenic bacteria were isolated and purified from the liver of S. chuatsi. And the identification of phenotypic information of the strain WJ2014-1 was conducted, including the biochemical identification and 16S rRNA gene sequence determination. Antimicrobial susceptibility test was conducted by disk diffusion technique. Results] The results of artificial infection tests by using WJ2014-1 to infect S. chuatsi displayed that the prevalence of symptoms and spontaneous onset symptoms were the same. According to morphological and biochemical characteristics as well as the result of 16S rRNA gene sequence analysis, the isolated strain WJ2014-1 was A. veronii. WJ2014-1 was susceptible to sulfamethoxazole, doxycycline, roxithromycin, cefotaxime, piperacillin and other 21 kinds of antibiotics. Meanwhile, it showed resistance to chloramphenicol, norfloxacin, nalidixic acid and other 9 kinds of antibiotics. Conclusion] The isolated bacterial strain WJ2014-1 was pathogenic to S. chuatsi, and prevented by administering drugs such as sulfamethoxazole, doxycycline and roxithromycin in fisheries production.