张杉杉,莫坤联,李静林,高博,冼健安,胡永华

• 1:河北农业大学海洋学院
• 2:中国热带农业科学院热带生物技术研究所
• 3:海南省海洋生物资源功能性成分研究与利用重点实验室

摘要(Abstract)：

【目的】探究海南文昌罗非鱼大规模持续性发病、死亡的原因。【方法】使用营养琼脂、胰蛋白胨大豆琼脂等培养基从患病肝、脾、肾组织中均分离到单一优势菌。对分离株进行形态特征、生理生化鉴定及16S rRNA基因序列分析确定其生物学地位，通过人工回归感染确定其致病性，利用纸片扩散法进行药物敏感性试验。【结果】分离菌与格氏乳球菌（Lactococcus garvieae）同源性最高并且聚合为一支，结合形态学特征和生理生化特征，鉴定为格氏乳球菌。血清杀菌实验表明，格氏乳球菌具有较强的抗宿主血清杀菌能力。回归感染实验表明，格氏乳球菌是致病菌，其感染罗非鱼的半致死剂量LD50为2.433×103 CFU/g（标准差为77.249 CFU/g）。药敏实验表明，格氏乳球菌具有广谱抗药性。【结论】新型病原格氏乳球菌对罗非鱼具有高感染性和致死率，研究结果可为罗非鱼格氏乳球菌病防治提供参考依据。

关键词(KeyWords)： 罗非鱼;格氏乳球菌;分离鉴定;致病性;耐药性

Abstract:

Keywords:

基金项目(Foundation): 海南省自然科学基金青年基金（323QN278）;; 农业农村部财政专项（NFZX2021）

作者(Author): 张杉杉,莫坤联,李静林,高博,冼健安,胡永华

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