Serum enzyme activity of Mugil cephalus Linnaeus artificially infected by Vibrio parahaemolyticus,Vibrio vulnificus and Vibrio harveyi

【Objective】The variations on innate immune activities of Mugil cephalus infected by inoculating microbes were studied to provide theoretical references for immunological control of mullet phytosis. 【Method】Mixed bacteria suspension with equal ratio of 4.5×106CFU/mL Vibrio parahaemolyticus, Vibrio vulnificus, Vibrio harveyi and normal saline(control group) were injected into the enterocoelia of Mugil cephalus. The activities of acid phosphatase(ACP), alkaline phosphatase(AKP), lysozyme(LSZ), superoxide dismutase(SOD), peroxidase(POD), glutamic oxaloacetic transaminase(GOT), and glutamic pyruvic transaminase(GPT) activity in serum of Mugil cephalus were investigated at different time(0,1,3,7, 11,15,19,23,27,31,35 d) by detecting the collected blood samples. 【Result】Symptoms appeared on the third day of infection. The activities of ACP, AKP, LSZ, SOD and POD presented the same tendency. They all decreased at first and then increased and decreased again. In the early stage of infection, the amino transferase of GOT and GPT showed a sharp rise at first and then slowly declined to the normal level. 【Conclusion】Exogenous microorganism could do harm to non-specific immune system and liver of Mugil cephalus. Nonspecific immune enzyme in serum could be used as the indicator for fish health.