HUANG Ting1, LI Li-ping1, WANG Rui1, ZHANG Bin1,GAN Xi1, LUO Hong-lin1, CHEN Fu-yan1,CAI Xiao-hui2,YANG Chuan-ping3, LIANG Wan-wen1, CHEN Ming1
1.Guangxi Key Laboratory of Aquatic Genetic Breeding and Healthy Aquaculture, Guangxi Academy of Fishery Sciences, Nanning 530021, China；2.Guangxi Key Laboratory of Marine Biotechnology，Guangxi Institute of Oceanology， Beihai 536000，China；3. Dangtu County Fisheries Bureau, Dangtu 243100，China
Abstract: Two bacterial strains TSG002 and TSG004 were isolated from the diseased ovate pompanoTrachinotusovatuscollected in Beihai，Guangxi Province,China in August of 2011,and were confirmed to be the pathogens of the diseased ovate pompano by animal challenge test, and by morphology, physiological and biochemical examination and 16S rRNA genetic analysis. In addition，the sensitivity of both strains to twenty-two antibiotics were studied. The results showed that strains TSG002 and TSG004 were similar to bacteriaStreptococcusagalactiaeandS.iniae, based on the morphology, physiology and biochemistry examinations. The phylogenetic analysis revealed that the l6S rRNA sequence of strains TSG002 (KF826095) and TSG004 (KF826094) has high similarity (99%) toS.agalactiae(NR040821.1) andS.iniae(AF335572.1) in GenBank. Phylogenetic tree ofStreptococcusspp. built according to 16S rRNA genes also showed that strains TSG002 and TSG004 are classified intoS.agalactiaeandS.iniaegroup, respectively.Both strains were found to be highly sensitive to nine drugs, including ceftriaxone，enrofloxacin, ofloxacin, amoxicillin and cephalothin. It is concluded that ovate pompano can be infected byS.agalactiaeandS.iniae, which were firstly and simultaneously found in one diseased ovate pompano.
2014, Vol. 29 
