南方农业学报Issue(3)：498-504,7.DOI:10.3969/j.issn.2095-1191.2014.3.498
罗非鱼致病性无乳链球菌的分离鉴定及药敏试验
Isolation, identification and drug susceptibility test of tilapia pathogen Streptococcus agalactiae
摘要
Abstract
[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.关键词
罗非鱼/无乳链球菌/分离鉴定/16S rRNA/药敏试验Key words
tilapia/Streptococcus agalactiae/isolation and identification/16S rRNA/drug susceptibility test分类
农业科技引用本文复制引用
黄艳华,彭亚,刘杰,彭民毅,黄钧,胡大胜,陈明,马旦梅,曾桂忠..罗非鱼致病性无乳链球菌的分离鉴定及药敏试验[J].南方农业学报,2014,(3):498-504,7.基金项目
广西科学研究与技术开发计划项目（桂科攻1123006-4）；广西水产畜牧兽医局专项项目（桂渔牧财［2011］52号，桂渔牧财［2012］30号，桂渔牧财［2013］35号）；南宁市科学研究与技术开发计划项目 （）
