半滑舌鳎腹水症病原的分离鉴定  

Isolation and identification of pathogenic bacterium associated with ascites in Cynoglossus semilaevisis

作　　者：徐晓丽[1] 尤宏争[1] 宋昀鹏 钟文慧[1] 李贺密 

机构地区：[1]天津市水产技术推广站,天津300221

出　　处：《东北农业大学学报》2015年第3期74-80,共7页Journal of Northeast Agricultural University

基　　金：天津市科技支撑计划项目(12ZCZDNC00900);天津市科委科技计划项目(13ZXNZNC07700)

摘　　要：从患病半滑舌鳎(Cynoglossus semilaevis)内脏及腹水中分离到优势菌株8301,回归感染试验证实菌株8301对半滑舌鳎具有致病性;采用形态学观察、生化特性分析、16S rDNA基因序列分析等方法对所分离菌株进行鉴定。结果表明,菌株8301为革兰氏阳性球菌,生化特性与海豚链球菌(Streptococcus iniae)较为接近,以16S rDNA基因为遗传标记构建系统发育树将菌株8301与海豚链球菌聚为一支,置信度为96%。结果判定引起此次半滑舌鳎腹水病的病原菌为海豚链球菌。对24种抗菌药物敏感性分析试验证实菌株8301对制霉菌素、利福平、青霉素、阿奇霉素等敏感,对罗红霉素、呋喃唑酮等具有抗性。Dominant bacteria designed as 8301 was isolated from ascites and kidney of diseased Cynoglossus semilaevisis and proved to be pathogenic strongly to C. semilaevisis by artificial chal enge. The biological characteristics including morphological, physiological and bio-chemical characteristics were exam-ined, and the 16S rDNA gene were partial y sequenced and compared with sequences deposited in Gen-Bank databases. The results showed that strain 8301 appeared gram-positive cocci in chains;based on the physiological and biochemical characteristic analysis, strain 8301 was identified as Streptococcus iniae. Phy-logeny analysis with 16S rDNA showed that strain 8301 was branched into the same cluster of S. iniae and the bootstrap was 96%. These results determined that the pathogen of causing ascites in C. semilaevisis was S. iniae. Antimicrobial susceptibility assay showed that strain 8301 was susceptible to nystatin, rifampi-cin, penicil in and azithromycin, but resistant to roxithromycin, furazolidone, etc.

关 键 词：半滑舌鳎 腹水症 海豚链球菌 16S RDNA 

分 类 号：S941.1[农业科学—水产养殖]