两株对虾幼体弧菌病病原的分离和鉴定

从患弧菌病的凡纳滨对虾（Litopenaeus vannamei）幼体中分离到两株病原菌zouA和zouB，常规形态和生理生化试验表明均为弧菌属菌种，弧菌编码鉴定系统分别鉴定为溶藻弧菌（Vibrioatginolyticus）和副溶血弧菌（V.parahaemolyticus）。副溶血弧菌R72H序列检测结果进一步证实菌株zouB为副溶血弧菌。对菌株zouA的16S rRNA基因序列分析表明该菌株与溶藻弧菌、副溶血弧菌等弧菌的相似性均高于98％，相互间不能区分；HSP60基因序列分析表明该菌株与溶藻弧菌相似性达98％以上，而与所有其它弧菌的相似性不到92％。结合表型和分子特征的鉴定结果，菌株zouA和zouB分别被鉴定为溶藻弧菌和副溶血弧菌。

Isolation and Identification of Two Pathogenic Strains Associated with Vibriosis of Shrimp Larvae

Two pathogenic strains zouA and zouB were isolated from Litopenaeus vannamei larvae which suffered from vibriosis, and were identified as Vibrio alginolyticus and V. parahaemolyticus by traditional bacterial identification method respectively. Strain zouB was confirmed further as V. parahaemolyticus by special R72H sequence test. 16S rRNA and heat shock protein (HSP60) genes partial sequences of strain zouA were determined. Phylogenetic tree of vibrios based on 16S rRNA gene sequences revealed that there was more than 98% sequence identity among zouA, V. alginolyticus, V. parahaemolyticus, et al., and could not be distinguished between each other. HSP60 gene sequences showed that strain zouA had sequence identity of more than 98% to V. alginolyticus, whereas had less than 92% to that of all the other vibrios. Combining phenotypic and molecular characters, zouA and zouB were identified as V. alginolyticus and V. parahaemolyticus respectively.