CAJ | 학술논문

【目的】对广西南宁市郊三塘镇某养殖场患病罗非鱼进行病原菌分离鉴定及药敏试验，旨在找出罗非鱼的发病原因，为该病的有效防治提供依据。【方法】用常规方法从患病濒死罗非鱼脑部分离病原菌，通过人工感染试验确定分离菌株的致病性，用API20 Strep生化鉴定系统和16S rRNA鉴定病原菌，并采用K-B纸片扩散法进行药敏试验。【结果】分离获得的4株革兰氏阳性球菌（GXN01、GXN02、GXN03和GXN04）对健康罗非鱼均有很强的致病性，是导致罗非鱼发病死亡的病原菌，经API20 Strep生化鉴定和16S rRNA鉴定均为无乳链球菌（Streptococcusagalactiae），与GenBank上已登录的无乳链球菌JQ039365、JQ039376、JQ990156、JQ039366、JF423948、HQ645984、GU217535菌株高度同源，同源性达99.2%~99.7%，4株分离菌株间也高度同源（99.9%）。药敏试验结果发现，4株无乳链球菌对先锋霉素VI、氧氟沙星、先锋必、盐酸沙拉沙星敏感，但对庆大霉素、氟哌酸、磺胺-6-甲氧嘧啶、磺胺对甲氧嘧啶等具有耐药性。【结论】引起广西南宁市三塘某养殖场罗非鱼发病死亡的病原菌为无乳链球菌，可选用先锋霉素VI、氧氟沙星、先锋必、盐酸沙拉沙星等药物进行防治。
【목적】대엄서남저시교삼당진모양식장환병라비어진행병원균분리감정급약민시험，지재조출라비어적발병원인，위해병적유효방치제공의거。【방법】용상규방법종환병빈사라비어뇌부분리병원균，통과인공감염시험학정분리균주적치병성，용API20 Strep생화감정계통화16S rRNA감정병원균，병채용K-B지편확산법진행약민시험。【결과】분리획득적4주혁란씨양성구균（GXN01、GXN02、GXN03화GXN04）대건강라비어균유흔강적치병성，시도치라비어발병사망적병원균，경API20 Strep생화감정화16S rRNA감정균위무유련구균（Streptococcusagalactiae），여GenBank상이등록적무유련구균JQ039365、JQ039376、JQ990156、JQ039366、JF423948、HQ645984、GU217535균주고도동원，동원성체99.2%~99.7%，4주분리균주간야고도동원（99.9%）。약민시험결과발현，4주무유련구균대선봉매소VI、양불사성、선봉필、염산사랍사성민감，단대경대매소、불고산、광알-6-갑양밀정、광알대갑양밀정등구유내약성。【결론】인기엄서남저시삼당모양식장라비어발병사망적병원균위무유련구균，가선용선봉매소VI、양불사성、선봉필、염산사랍사성등약물진행방치。
[Objective]Pathogenic bacteria strains were isolated and identified from diseased tilapia cultured in a fish farm in Santang Town, Nanning City, Guangxi. A drug sensitivity test was conducted to seek out the aetiological agent and provide references for effective prevention and control. [Method]The strains were separated from the brain tissue in dying tilapias using routine method. Pathogenicity of the strains was determined by an artificial infection experiment. The strains were identi-fied using API20Strep and the 16S rRNA sequences. K-B was applied to test the drug sensitivity. [Result]Four Gram-positive cocci (GXN01, GXN02,GXN03 and GXN04) possessed strong pathogenicity against healthy tilapia and they might be the aetiological agent causing tilapia to death. The four strains were identified as Streptococcus agalactiae. All the strains shared 99.2%-99.7% similarities with those S. agalactiae strains reported in GenBank (JQ039365,JQ039376,JQ990156, JQ039366, JF423948, HQ645984 and GU217535). These four strains also shared high similarities(99.9%) with each other. Drug susceptibility test results showed that the four strains were sensitive to ofloxacin, cephalosporinVI, cefobid and sarafloxacin hydrochloric,but resistant to gentamicin, norfloxacin, sulfadoxine-6-methoxymethoxypyrimidine and sulfa-methoxy-pyrimidine. [Conclusion]The deaths of tilapia might be caused by S. agalactiae infection. Four kinds of drugs (CephalosporinVI, Ofloxacin, Cefobid and Sarafloxacin hydrochloric) could be used for prevention and treatment.