日本鳗鲡混合感染迟缓爱德华氏菌与创伤弧菌的分离与鉴定

目的对日本鳗鲡混合感染迟缓爱德华氏菌(Edwardsiella tarda)和创伤弧菌(Vibrio vulnificus)的病原进行了分类鉴定。方法对两株病原菌进行了形态、API-ID32E鉴定系统和分子生物学鉴定,分别测定了菌株AnGH080301和An-GH080302的16SrRNA和HSP60基因序列,构建了系统进化树。结果按形态特征和API-ID32E鉴定系统分别初步鉴定菌株AnGH080301和AnGH080302为迟缓爱德华氏菌和创伤弧菌。菌株AnGH080301的16SrRNA基因部分序列(登录号FJ646618)与迟缓爱德华氏菌的16S rRNA基因(登录号AB050832)同源性最高,达99.7%;菌株AnGH080302的HSP60基因部分序列(登录号FJ646619)与创伤弧菌HSP60基因(登录号BA000037)的同源性最高,达99.8%。结论综合菌株的生理生化特性和分子生物学鉴定结果,可将菌株AnGH080301和AnGH080302分别鉴定为迟缓爱德华氏菌和创伤弧菌,迟缓爱德华氏菌与创伤弧菌均为人兽共患病病原,其混合感染日本鳗鲡致病的报道尚属首次。

Isolation and identification of pathogenic bacteria from Anguilla janponica mixedly infected with Edwardsiella tarda and Vibrio vulnificus

Edzvardsiella tarda and Wibrio vulnificus are pathogens that can infect both humans and animals. Two strains were isolated from the diseased Anguilla janponica cultivated in Humen, Guangdong province in March, 2008. Strain AnGH080301 and AnGH080302 were confirmed to be the pathogen of the disease by challenge test. Traditional physiological and biochemical experiments were done, while API ID32E system was also applied in the bacterial classification. The results showed that strain AnGH080301 and AnGH080302 were similar to Edwardsiella tarda and Vibrio vulnificus respectively in most of the phenotypes. In order to investigate the phylogenetic position of the pathogens, 16S rRNA genes partial sequences of strain AnGH080301 and heat shock protein （HSP60） genes partial sequences of strain AnGH080302 were determined respectively. The results showed that the 16S rRNA gene sequences of strain AnGH080301 （FJ646618） was 1431 bp in length and its similarity with Edwardsiella tarda （AB050832） in GenBank was 99. 7 G. Phylogenetic tree of Edwardsiella based on 16S rRNA genes showed that strain AnGH080301 clustered together with Edwardsiella tarda. The HSP60 gene sequences of strain AnGH080302 （FJ646619） was 505 bp in length and its similarity with Vibrio vulnificus （BA000037） in GenBank was 99. 8 % . Phylogenetic tree of Vibrio based on HSP60 genes showed that strain AnGH080302 clustered together with Vibrio vulnificus. Based on the results obtained, the strain AnGH080301 and AnGH080302 were identified as Edwardsiella tarda and Vibrio vulnificus respectively, and it is the first report about the mixed infection of Edwardsiella tarda and Vibrio vulni ficus in Anguilla janponica.