饶颖竹 梁静真 陈蓉 杨廷宝

摘要：【目的】了解海水养殖斜带石斑鱼弧菌病的病原，为生产中有效防治石斑鱼弧菌病提供科学依据。【方法】采用常规方法进行患病斜带石斑鱼病原菌分离，人工感染试验确定其致病性，以形态学观察、生理生化测试结合16S rRNA和gyrB基因序列分析等方法进行菌株鉴定，并以K-B纸片扩散法进行药敏试验。【结果】从广东省湛江市某养殖场患病斜带石斑鱼中分离获得1株优势菌株（M1），经人工感染试验证实其对斜带石斑鱼具有较强的致病性。M1菌株的16S rRNA序列和gyrB基因序列与GenBank数据库中的鳗弧菌具有较高相似性，其同源性均在95.7%以上。根据M1菌株的形态特征、生理生化特性及分子特征，可鉴定其属于弧菌属的鳗弧菌（Vibrio anguillarum）。药敏试验结果显示，M1菌株对庆大霉素、新生霉素、阿奇霉素、氟苯尼考、利福平、诺氟沙星和左氟沙星等7种药物高度敏感，对阿洛西林、强力霉素、链霉素、复方新诺明和甲氧苄啶等14种药物敏感。【结论】引起广东省湛江市某养殖场海水养殖患病斜带石斑鱼弧菌病的病原菌为弧菌属鳗弧菌，生产中可适度选用氟苯尼考、强力霉素、复方新诺明和甲氧苄啶等抗菌药物进行防治。

关键词： 斜带石斑鱼；鳗弧菌；16S rRNA序列；gyrB基因；药敏试验

中图分类号： S965.334.42 文献标志码：A 文章编号：2095-1191（2016）08-1416-07

Abstract：【Objective】In order to provide scientific basis for effective prevention and control of grouper vibriosis， the pathogen was isolated and identified from diseased Epinephelus coioides， and its drug sensitivity was tested. 【Method】The pathogen was isolated by conventional method， and its pathogenicity was determined by artificial infection. Based on morphological observation， physiological-biochemical test， and sequences analysis of 16S rRNA and gyrB gene， the pathogen was identified. And its drug sensitivity was tested by Kirby-Bauer disc diffusion method. 【Result】One dominant bacterium strain was isolated from diseased E. coioides from fish farm in Zhanjiang， Guangdong， and named M1. It was pathogenic to E. coioides in artificial challenge test. The sequence analysis showed that， 16S rRNA and gyrB gene sequences of M1 shared high homology（more than 95.7%） with Vibrio anguillarum from GenBank database. Moreover， the strain M1 was identified as V. anguillarum based on its morphology， physiological-biochemical characteristics and molecular features， and it was highly sensitive to gentamicin， novobiocin， azithromycin， florfenicol， rifampicine， norfloxacin and levofloxacin， and moderately sensitive to 14 kinds of drugs， viz.， azlocillin， doxycycline， streptomycin， trimethoprim（TMP）， SMZ+TMP and so on. 【Conclusion】V. anguillarum is pathogen causing vibriosis of E. coioides cultured in a fish farm of Zhanjiang， Guangdong， and can be controlled by florfenicol， doxycycline， SMZ+TMP， TMP， etc.

Key words： Epinephelus coioides； Vibrio anguillarum； 16S rRNA sequence； gyrB gene； drug sensitivity test

0 引言

【研究意义】斜带石斑鱼（Epinephelus coioides）俗称青斑，隶属于鲈形目（Perciformes）鮨科（Serranidae）石斑鱼亚科（Epinephelinae）石斑鱼属（Epinephelus），因具有生长快、适应能力强、饲养成活率高、经济价值高等特点，现已成为重要的海水鱼类养殖对象。……