关键词: 斜带石斑鱼, 哈维弧菌, 细菌鉴定, 药敏, Epinephlus coioides, Vibrio harveyi, bacterial identification, sensitivity test to antibacterial agents

Abstract: Serious disease outbreak occurred in a groupers Epinephelus coioides culture farm in Jinjiang，Fujian province in Julv 2011. ih e weight oi diseased groupers was 3 ?10 g. The characteristics oi aiseased grouper were observed，displaying body colour darkening，feeding refused， swimming slowly，and redness of the liver and spleen spot. Two strains of bacteria were isolated from the liver and spleen of moribund groupers and designated as strain 201107 - I and 2011107 - II in July 2011. A ll the two isolates were identified as Vibrio harveyi by physiological and biochemical tests combining with 16S rRNA gene sequence analysis. A rtificial in jection demonstrated that strain 201107 - 1 and 201107 - II were both pathogenic to E. coioides . Strain 201107- II showed the stronger toxicity to E. coioides and was used to the subsequent analysis. Three experimentaltypes of artificial infections were conducted， muscle injection， celiac injection and wound immersion， to confirm the toxicity of strain 201107- II ，and the half lethal dose ( LD5。) to E. coioides was 4. 3 × 104 , 2. 9 ×105 and 5. 4 × 106 c fu /g fish weight，respectively. We also isolated a bacterial strain from this artificial infected E. coioides，and this strain was identified as the same strain as the 201107 - II using traditional physiological and biochemical characterization along with molecular 16S rRNA gene analysis. The sensitivity tests of antibacterial agents indicated that the bacterial strain 201107 - II was sensitive to erythromycin，spectinomycin，chloramphenicol，and other 13 agents ； middling sensitive to furazolidone， clarithrom ycin， and ciprofloxacin and other 6 agents; resistant to oxacillin，penicillin G，vancomycin and other 10 agents. This study will provide necessary data about the sustainable and healthy development of E . coioides culture