黄颡鱼源拟态弧菌的分离鉴定

Isolation and Identification of Vibrio mimicus GZ 201811 Strain in Pelteobagrus fulvidraco

采用病理剖检、分离培养、染色镜检、生化试验和16S rRNA基因序列分析等方法对分离菌株进行鉴定,结果显示该分离菌的培养特性、菌落形特征、生理生化特征均与拟态弧菌相同;药敏试验结果表明,该分离菌对链霉素、罗红霉素、丁胺卡那、氧氟沙星高度敏感,对多黏菌素敏感,对青霉素、氟苯尼考、头孢曲松、强力霉素耐药;16S rRNA基因序列同源性分析结果显示,该分离菌与弧菌科弧菌属的同源性为92.8%~99.9%,其中与中国分离的2株拟态弧菌的同源性最高(99.9%)。遗传进化树结果表明,分离株与霍乱弧菌、易北河弧菌、溶藻弧菌、拟态弧菌等自成一个分支,其中在这分支下与中国分离的拟态弧菌SCCF04(KC503059.1)、拟态弧菌XQ(KJ604709.1)单独另成一个小分支。从黄颡鱼中分离出1株拟态弧菌,并将命名为201811,试验结果可为黄颡鱼拟态弧菌病的防控提供参考。

In this experiment,the isolate as identified by means of pathological anatomy,isolation and culture,staining and microscopic examination,biochemical test and 16S rRNA sequence analysis.The results showed that the culture characteristics,colony shape characteristics,physiological and biochemical characteristics of the isolated strain were the same as those of Vibrio mimicus reported in the literature.The results of drug sensitivity test showed that the isolate was highly sensitive to streptomycin,roxithromycin,amikacin and ofloxacin,sensitive to polymyxin,and resistant to penicillin,florfenicol,ceftriaxone and doxycycline.16S rRNA sequence homology analysis showed that the homology between the isolated strain and Vibrio was 92.8%-99.9%,of which the homology between the isolated strain and Vibrio mimicus of China was the highest,99.9%.The results of genetic phylogenetic tree showed that the isolate was in the same branch with Vibrio cholerae,Vibrio albensis,Vibrio alginolyticus and Vibrio mimicus,among which Vibrio mimicus SCCF 04(KC 503059.1),Vibrio mimicus XQ(KJ 604709.1)isolated from China and the isolate in this study were in a small branch.Based on the above resuls,a Vibrio mimicus strain was successfully isolated from Pelteobagrus fulvidraco and named 201811.The results provided a theoretical basis for the prevention of Vibrio mimicus infection in Pelteobagrus fulvidraco.