南美白对虾病原性豚鼠气单胞菌的分离与药敏特性

为查明引起上海青浦地区养殖南美白对虾黄腿病的病原菌,提供养殖户防控该病的有效药物,采用传统方法从患黄腿病的南美白对虾肝胰腺组织中进行了病原菌的分离,通过人工回归感染试验确定了病原菌株,采用API ID32GN生理生化鉴定和16S rRNA序列分析对病原菌株进行鉴定,通过纸片扩散法分析病原菌株的药敏特性。结果表明,从病虾的肝胰腺中分离到一株病原菌(QPX1),经生理生化特性与16S rRNA序列分析确定其为豚鼠气单胞菌(Aeromonas caviae)。此外,菌株QPX1对阿莫西林、多粘菌素B、磺胺异噁唑、复方新诺明、卡那霉素、吡哌酸、新霉素、庆大霉素、氟苯尼考、链霉素、恩诺沙星、诺氟沙星、奈替米星等抗生素高度敏感。本研究证实豚鼠气单胞菌是南美白对虾黄腿病的病原菌,生产上可选用新霉素、氟苯尼考、恩诺沙星等常规水产用抗生素作为该病的防控用药。

Isolation and antibiotic susceptibility of an Aeromonas caviae pathogen from yellow leg disease-infected Penaeus vannamei

In order to investigate the bacterial pathogen that caused the yellow leg disease of Penaeus vannamei farmed in Qingpu district,Shanghai and provide reference fishery drugs for effective control of this disease,bacterial isolates were isolated from naturally infected P.vannamei using traditional methods and their pathogenicity was determined by artificial infection test.The identification of the pathogenic isolate was conducted by API ID32GN phenotypic identification and 16S rRNA sequence analysis.Its antibiotic susceptibility was tested by disc diffusion method.The results showed that strain QPX1 was isolated from hepatopancreas of diseased P.vannamei and was identified as Aeromonas caviae based on phenotypic characteristics and 16S rRNA sequences analysis.It exhibited highly sensitivity to amoxicillin,polymyxin B,sulfafurazole,cotrimoxazole,kanamycin,pipemidic acid,neomycin,gentamicin,florfenicol,streptomycin enrofloxacin norfloxacin,netilmicin.This present study confirms A.caviae as a pathogen of yellow leg disease in Penaeus vannamei,and common fishery antibiotics such as neomycin,florfenicol and enrofloxacin can be selected as a reference for the control of this disease.