半滑舌鳎源美人鱼发光杆菌美人鱼亚种的分离鉴定

摘要

2016年5月河北省秦皇岛市昌黎县某海水养殖基地半滑舌鳎突发大批死亡,为了确定引起死亡的病原菌,无菌采集心血进行病原菌分离鉴定,16S rDNA基因序列分析与GenBank中公布的美人鱼发光杆菌参考株序列同源性为99.6%,被鉴定为美人鱼发光杆菌;进一步通过生化特性分析,被确认为美人鱼发光杆菌美人鱼亚种.动物回归试验结果表明,其对舌鳎鱼具有很强的致病性,其LD50为3.1×104CFU/mL,且对哺乳动物具有致病性.药敏试验结果显示,分离菌对诺氟沙星、恩诺沙星、环丙沙星,乙酰甲喹高度敏感;对多西环素、阿米卡星中敏感;对庆大霉素、头孢曲松、替米考星等不敏感.%In May 2016,an epizootic occurred among cultured tongue sole caused mass deaths in a fish farm in Qinhuangdao,China. In order to find out etiological agent,a strain of bacterium was isolated from the aseptically collecting ascites and other tissues of sick tongue sole.The isolate was identified as Photobacterium damselae subsp. damsela by isolation culture, Gram staining, physiological identification, morphological observation, biochemical identification and 16S rDNA sequence analysis. It is showed that the isolate shared 99.6% homology with reference strain in GenBank. The results of animal regression test showed that the isolate can pathogenic and the pathogenicity was relatively strong. The LD50of was 3.1×104CFU/mL, and pathogenicity to mammals. The results of the antibiotic resistance test showed the isolate was highly sensitive to Norfloxacin, Enrofloxacin, Ciprofloxacin,Maquindox;was insensitive to Gentamicin,Ceftriaxone,Tilmicosin and so on,and it had different degrees to other drugs.