青鱼源布氏柠檬酸杆菌的分离鉴定及药敏试验

Isolation,identification and drug susceptibility test of Citrobacter braakii from Mylopharyngodon piceus

为确定吉林省某渔场致青鱼细菌性死亡的病原,从病死青鱼肝中分离得到1株优势菌,命名为QG1511。经形态学观察、生化试验、16S rRNA基因序列测定及系统发育学分析鉴定为布氏柠檬酸杆菌。致病性试验结果表明,分离菌株QG1511感染健康青鱼可复制自然发病症状。药敏试验结果表明,分离菌株QG1511对磺胺间甲氧嘧啶、庆大霉素、红霉素、阿奇霉素、阿莫西林、阿米卡星耐药,对氯霉素、氟苯尼考、强力霉素、恩诺沙星、环丙沙星敏感。本试验药敏结果为青鱼源布氏柠檬酸杆菌的防治提供了科学依据。

To determine the pathogenic bactera in Mylopharyngodon piceus,a dominant bacteria strain named QG1511 was isolated from hepar of sick piceus. It was identified as Cftrobacter braakii according to its morphological, physiobiochemical characteristics and 16S rRNAsequencing analysis. Challenged tests were taken to detect pathogenicity of QG1511 in healthy piceus. The results indicated that the QG1511 strain could cause the piceus showing similar symptoms to that of original cases. The minimal inhibitory concentration of ll antibiotics against dominant bacteria was determined by the mi- crodilution method. The results showed that the isolate was resistance to sulfamerazine, gentamicin erythrocin, azithromycin and amoxicillin, but sensitive to chloramhenicols, florfenicol, doxycy- cline, enrofloxacin and ciprofloxacin, which provides the theoretical basis for treatment of the dis- ease caused by Citrobacter braakii in mylopharyngodon piceus.