南美白对虾白便综合征病原霍乱弧菌的分离与药敏试验

Isolation and Antimicrobial Sensitivity Test of A Vibrio cholerae Strain from Penaeus vannamei with White Fecal Syndrome

为确定南美白对虾白便综合征的病原菌及其药物敏感性,采用传统方法从患白便综合征的南美白对虾肝胰腺中分离到病原菌菌株BB31,结合API 20E革兰阴性菌鉴定系统、16SrDNA序列及聚类分析对菌株BB31进行了鉴定,并通过纸片琼脂扩散法对菌株BB31的药物敏感性进行了测定。结果表明,菌株BB31为霍乱弧菌（GenBank登录号：KF446244）,其16SrDNA序列与GenBank数据库中弧菌菌株的16S rDNA序列有99%～100%的同源性,而且与霍乱弧菌菌株RD1（GenBank登录号：KF307775）的亲缘性最近。菌株BB31对四环素、庆大霉素、恩诺沙星、氧氟沙星、诺氟沙星等抗生素的敏感性高,对磺胺甲氧嘧啶、呋喃唑酮、复方新诺明等抗生素不敏感。本研究证实霍乱弧菌是南美白对虾白便综合征的病原菌,庆大霉素、诺氟沙星等常规渔药可作为防控霍乱弧菌引起的南美白对虾白便综合征的用药参考。

In order to confirm the bacterial pathogen of Penaeus vannamei white fecal syndrome and its an- timierobial sensitivity, a pathogenic strain BB31 was isolated from white fecal syndrome Penaeus van- namei using traditional methods, identified by API 20E Gram negative bacterial identification system, 16 S rDNA sequence and phylogenetic analysis. Its antimierobial susceptibility was also analyzed by Kirby- Bauer test. The results showed that strain BB31 was a Vibrio cholerae strain with its GenBank accession No. KF446244, its 16 S rDNA sequence had a 99%-100% homology with those of Vibrio strains, and showed a closest relationship to that of V. cholerae strain RD1 with GenBank accession No. KF307775. Strain BB31 exhibited a high sensitivity to tetracycline, gentamycin, enrofloxacin, ofloxacin and norfloxa- cin, showed a resistance against sulfametoxydiazine, compound sulfamethoxazole, furazolidone. This study confirmed Vibrio cholerae as a pathogen of white fecal syndrome Penaeus vannamei, and common fishery antimicrobial such as gentamycin and norfloxacin may be regarded as useful antimierobial in the control of Penaeus vannamei white fecal syndrome caused by Vibrio cholerae.