一株罗非鱼无乳链球菌的分离鉴定及药敏试验  

Isolation,Identification and Antimicrobial Susceptibility Test of Streptococcus agalactiae in Tilapia

作　　者：李永福[1] 李敏 叶毅飞 丁文桂 黄炳炽[1] 张险朋[1] Li Yongfu;Li Min;Ye Yifei;Ding Wengui;Huang Bingchi;Zhang Xianpeng(Dongguan Center for Animal Disease Prevention and Control,Dongguan,Guangdong 523086,China;Foshan University,Foshan,Guangdong 528231,China)

机构地区：[1]东莞市动物疫病预防控制中心,广东东莞523086 [2]佛山科学技术学院,广东佛山528231

出　　处：《中国动物检疫》2022年第5期127-135,共9页China Animal Health Inspection

基　　金：东莞市2021年度省乡村振兴战略专项(20211800400112)。

摘　　要：为确定东莞市某养殖场罗非鱼发病的原因,有针对性制定防治措施,采集发病罗非鱼的脑、肝脏、脾脏、肾脏等组织样品进行细菌分离培养鉴定,通过VITEK-2 Compact进行生化鉴定和16S rRNA基因序列分析以及系统进化树构建,并对分离菌株(DG210721)进行药敏试验。结果显示:分离纯化培养的菌株特征、形态和生化鉴定结果均与无乳链球菌相符;16S rRNA基因序列分析发现,分离菌株与罗非鱼无乳链球菌(JQ039371)同源性高达100%且亲缘关系最近;分离菌株对药物的敏感性由高到低依次是盐酸多西环素、恩诺沙星、甲砜霉素、氟苯尼考、氟甲喹、磺胺甲噁唑+甲氧苄啶、磺胺间甲氧嘧啶钠、硫酸新霉素。结果表明:该养殖场罗非鱼发病的原因之一是无乳链球菌感染;分离菌株遗传序列较稳定,并对部分临床使用的药物产生了一定的耐药性。结果提示,需要加强罗非鱼无乳链球菌感染的防控,定期采样检测,及时确诊,选用敏感药物进行科学防治。In order to determine the causes of tilapia disease in a farm in Dongguan City,and to develop targeted countermeasures,brain,liver,spleen,kidney and other tissue samples were collected from diseased tilapia for bacterial isolation,culture and identification,followed by biochemical identification using VITEK-2 Compact,16S rRNA gene sequence analysis and construction of a phylogenetic tree,and finally antimicrobial susceptibility test on the isolated strain(DG210721).The results showed that the characteristics,morphology and biochemical identification results of the obtained strain were consistent with those of streptococcus agalactiae;it was found that,after 16S rRNA gene sequence analysis,the homology between the isolated strain and streptococcus agalactiae(JQ039371)was up to 100%,with closest genetic relationship;the isolated strain,from strong to weak,was sensitive to doxycycline hydrochloride,enrofloxacin,thiamphenicol,florfenicol,fluoromequine,sulfamethoxazole+trimethoprim,sulfamethoxam sodium and neomycin sulfate.In conclusion,streptococcus agalactiae infection was one of the causes leading to tilapia disease in the farm,and the isolated strain,with stable genetic sequence,was resistant to some clinical drugs to some extent.Therefore,it was necessary to further prevent and control streptococcus agalactiae infection in tilapia,regularly sample for detection,diagnose in time,and scientifically prevent and control the disease using sensitive drugs.

关 键 词：无乳链球菌 细菌分离鉴定 16S rRNA 药敏试验 罗非鱼 

分 类 号：S851.3[农业科学—预防兽医学]