Isolation and identification of pathogen (Vibrio harveyi) from sea perch, Lateolabrax japonicus

Mass motilities of sea perch (Lateolabrax japonicus) occurred in Jiaonan fishery farms, Qingdao, Shandong Province from April to May 1999. The main syndromes of the diseased fish are rotting fins and rotting tails. One strain of bacteria SF 1 was isolated from the diseased sea perch, and another strain SF 3 was isolated from the diseased sea perch challenged by SF 1 by muscle injection. Most of the morphological characteristics of these two isolations are the same. They were identified as Vibrio harveyi by 64 test items physiological and biochemical characteristics. The sensitive test shows that among 33 chemotherapeutants, the pathogen are resistant to 21 and sensitive to chloramphenicol, ceftriaxone, cefotaxime, cefamandole, nitrofurantoin, trimethoprim,piperacillin,sulfonamides,sulfamethoxazole,and polymyxin E, etc.