乌鳢源舒伯特气单胞菌生物学特性及其药物敏感性分析  

Biological characteristics and drug susceptibility of Aeromonas schubertii WL-4 isolated from snakehead

作　　者：莫金凤[1] 姜兰[2] 吴灶和[1] 

机构地区：[1]仲恺农业工程学院广州市水产病害与水禽养殖重点实验室,广东广州510225 [2]中国水产科学研究院珠江水产研究所,广东广州510380

出　　处：《水产学报》2016年第3期484-494,共11页Journal of Fisheries of China

基　　金：广州市科技计划(201300000207);广东省科技计划(2011B020307001)~~

摘　　要：为了解乌鳢源舒伯特气单胞菌WL-4菌株的生理生化、生长特性、致病因子等生物学特征,以及其对多种药物的敏感性,使用细菌生化鉴定仪检测菌株的生理生化特性,比较不同温度、盐度及p H条件下菌株的生长特征;通过人工回归感染分析菌株的致病性,测定相关的毒力因子并采用PCR方法扩增毒力基因;采用微量二倍稀释法测试菌株对20种抗菌药物的最小抑菌浓度。结果发现,与模式菌株(ATCC43700)相比,两菌株的大部分生理生化特性相同,16S r RNA基因比对,相似度达99.9%;WL-4菌株的最适生长温度为30°C,最适生长盐度为5,最适生长p H为7;29°C时,腹腔注射感染乌鳢苗种的半数致死浓度(LC50)为1.2×106 CFU/m L;该菌株具有溶血性、蛋白酶活性和脂肪酶活性;WL-4菌株对磺胺类及酰胺醇类等8种药物具有耐药性,而对多西环素、新霉素、氨苄西林等12种药物敏感。研究表明,WL-4菌株的生物学特征与其引起的乌鳢内脏类结节病的发生情况相吻合,致病菌的药物敏感性与药物使用情况存在相关性。Aeromonas schubertii had caused snakehead disease with white spots in internal organs, which resulted in economic losses in snakehead industry. In this study, A. schubertii strain WL-4 which was isolated from the snakehead（Channa maculate ♀×C. argus ♂） was analyzed in relation with its physiology and biochemistry characteristics, its growth characteristics and virulence factors, and its susceptibility was tested against 20 antibiotics. Its physiology and biochemistry characteristics were tested by using bacterial biochemical identification instrument and its growth situation was analyzed at different temperatures, salinities and p H values.In comparison with the type strain, A. schubertii ATCC43700, A. schubertii WL-4 strain was almost same as the type strain in major physiological and biological characteristics. Moreover, 16 S r RNA gene of A. schubertii WL-4strain is 99. 9% similar to that in A. schubertii ATCC43700. The results of growth characteristics showed that the WL-4 strain＇s optimum growth temperature was 30 ℃, optimal salinity was 5 and optimum p H was 7. In addition,the WL-4 strain exhibited virulence to snakeheads（25±5）g in experimental challenges with LC50 being 1. 2×10^6CFU/mL. The WL-4 strain was positive for hemolytic activity, and elastase and lipase activity by phenotypic determination. Susceptibility tests, which detected the minimum inhibition concentration（MIC） of 20 antibacterial agents by trace double dilution method, showed that the strain WL-4 was resistant to sulfonamides and amide alcohols, and susceptible to enrofloxacin, norfloxacin, doxycycline, neomycin, ampicillin and so on. In conclusion,biological characteristics of the WL-4 strain were consistent with the occurrence of the disease with white spots in snakeheads＇ internal organs which were caused by A. schubertii. In addition, the results of antibacterial susceptibility tests may have an applied value in the control of A. schubertii infection agents in aquaculture.

关 键 词：舒伯特气单胞菌 生长特性 毒力因子 药物敏感性 

分 类 号：S941[农业科学—水产养殖]