Analysis of the Pathogenic Bacteria and Drug Sensitivity Test of the Tail-rot Pseudosciaena crocea Cultured in Marine Cage in Zhoushan

The tail-rot disease of Pseudosciaena crocea is one of the major diseases in marine cage-cultured Pseudosciaena crocea in Zhoushan.To explore the pathogen of tail-rot disease,two strains of pathogenic bacteria(S030901 and S030902) were isolated from the diseased Pseudosciaena crocea.The bacteria were cultivated;meanwhile,identification,artificial infection and drug sensitivity test were also carried out.Artificial infection showed that strain S030901 was high pathogenic,which caused 83.3 %～100 % specimen to death,while strain S030902 was almost nonpathogenic.According to the shapes and biochemical behaviors,strain S030901 was identified as vibrio harveyi,which was the main pathogen causing the tail-rot disease in marine cage-cultured Pseudosciaena crocea in Zhoushan.The drug sensitivity test showed that strain S030901 was highly sensitive to 10 antibiotics including norfloxacin, and was moderately sensitive to 3 drugs including doxycycline,but was not sensitive to other 11 drugs such as amikacin. Its resistance to different antibacterial agents is various; it is hence necessary to select antibacterial agents according to the drug sensitivity test.