摘要
[ Objective ] This study was to investigate the preventive effect of cecropin and lysozyme on skin fester disease in Trionyx sinensis. [ Method ] By employing intramuscular injection method, the preventive effect of mixtures of cecropin （10 mg/kg） and lysozyme（ 10 mg/kg） and of cecropin（6 mg/kg） and lysozyme（ 5 mg/kg） were challenged on Aeromonas encheleia-caused skin fester disease in T. sinensis. The mortality and relative percent survival were used evaluate the preventive effect of different drugs. The serum agglutination titer, cytophagocytosis and bactericidal activity were detected to compare the effect of drugs on the immunity and disease resistance of T. sinensis. [ Result] The residue concentrations of gentamicin and lysozyme in serum were compared to evaluate the side effect of drugs used challenged. The results showed that combined use of cecropin and lysozyme gave the best preventive effect and immunity in T. sinensis, with an extremely significant difference from other treatments （ P 〈 0.01 ）. Analysis of drug residue in serum indicated that lysozyme was completely metabolized 6 days after medication, while gentamicin residue was still observed 12 days later. [ Conclusion] The combined application of cecropin and lysozyme showed better preventive effect than antibiotics in fester disease of T. sinensis. Moreover, no drug residue and side effect were observed in the combined use treatment. This method avoids the side effect of antibiotics, worthy of extension at commercial scale.
[ Objective ] This study was to investigate the preventive effect of cecropin and lysozyme on skin fester disease in Trionyx sinensis. [ Method ] By employing intramuscular injection method, the preventive effect of mixtures of cecropin （10 mg/kg） and lysozyme（ 10 mg/kg） and of cecropin（6 mg/kg） and lysozyme（ 5 mg/kg） were challenged on Aeromonas encheleia-caused skin fester disease in T. sinensis. The mortality and relative percent survival were used evaluate the preventive effect of different drugs. The serum agglutination titer, cytophagocytosis and bactericidal activity were detected to compare the effect of drugs on the immunity and disease resistance of T. sinensis. [ Result] The residue concentrations of gentamicin and lysozyme in serum were compared to evaluate the side effect of drugs used challenged. The results showed that combined use of cecropin and lysozyme gave the best preventive effect and immunity in T. sinensis, with an extremely significant difference from other treatments （ P 〈 0.01 ）. Analysis of drug residue in serum indicated that lysozyme was completely metabolized 6 days after medication, while gentamicin residue was still observed 12 days later. [ Conclusion] The combined application of cecropin and lysozyme showed better preventive effect than antibiotics in fester disease of T. sinensis. Moreover, no drug residue and side effect were observed in the combined use treatment. This method avoids the side effect of antibiotics, worthy of extension at commercial scale.
