南美白对虾弧菌病病原的分离和鉴定  

Identification and characterization of pathogenic bacteria causing vibriosis in cultured American white shrimp( Penaeus vannamei)

作　　者：金春英[1] 

机构地区：[1]华侨大学化工学院,福建厦门361021

出　　处：《海洋环境科学》2013年第5期647-651,共5页Marine Environmental Science

基　　金：国家自然科学基金项目(31272684);福建省自然科学基金计划项目(2010J05074);国家海洋局海洋生物遗传资源重点实验室开放研究基金项目(HY201102)

摘　　要：2011年夏季广东湛江养殖南美白对虾(Penaeus vannamei)暴发弧菌病。症状主要表现为对外界刺激反应迟钝、食欲减退、体表发红、肌肉白浊、腮部变黄溃烂。从病虾肝胰腺分离出优势菌并命名为E385。经人工感染发现,分离株感染试验虾出现与自然发病虾相似的症状,确定该菌为导致本次弧菌病爆发的病原菌。对E385进行鉴定揭示该菌革兰氏染色阴性,菌体呈短杆状,极生单鞭毛。形态学观察和生理生化特征测定表明,E385与弧菌属的轮虫弧菌Vibrio rotiferianus最为接近。为了进一步确定其分类地位,对16S rRNA进行序列分析和同源性对比,并构建系统发育树,结果表明菌株E385与轮虫弧菌V.rotiferianus聚为1个分支,且同源性达99.4%。综合上述鉴定结果,引起湛江地区南美白对虾弧菌病的病原被鉴定为轮虫弧菌。这是第一次轮虫弧菌作为海水动物病原菌被报道。药敏试验结果表明,氨苄青霉素、羧苄青霉素和青霉素G这三个青霉素类药物对轮虫弧菌E385抑制作用最强,但该菌株对庆大霉素、卡那霉素、林可霉素、甲硝唑、链霉素和多粘菌素B不敏感。An outbreak of vibriosis of the cultured American white shrimp （Penaeus vannamei ） occurred in a farm in Zhanjiang, Guangdong Province in August of 2011 and caused significant mortality. Typical signs of disease included inactivity, anorexia, reddening of the shrimp body, opaque and whitish musculature, and tea brown and ulcerative gill. One bacterial strain （E385） was isolated from the hepatopancreas of moribund shrimp. The pathogenicity of the isolate was tested. The challenged shrimp presented the similar external signs to natural infected shrimp,which proved that the isolate E385 was the patbogenic bacteria that triggered this disease. E385 was Gram negative and short rod with single polar flagellum under electron microscope. Phenotypic and biochemical identification revealed that E385 exhibited relatedness to Vibrio rotiferianus. In order to identify the phylogenetic position of E385, the 16S rRNA genes was amplified and compared with other Vibrio spp. in GenBank, homology analysis and phylogenetic study showed that E385 has the highest similarity to V. rotiferianus, with 99.4% identity. According to these results, the pathogen causing shrimp vibriosis in Zhan- jiang was identified as an isolate of K rotiferianus. This is the first report that E rotiferianus was found as the pathogenic bacteria of cultured marine animal. The data of drug sensitivities indicated that carbenicillin, ampicillin and penicllin G could strongly inhibit growth of E385 strain, but gentamicin, kanamycin, lincomycin, metronidazole, streptomycin and polymyxin B didn＇ t.

关 键 词：轮虫弧菌 南美白对虾 病原菌 16S RRNA 药敏试验 

分 类 号：S945.49[农业科学—水产养殖]