梭子蟹牙膏病病原菌——溶藻弧菌的鉴定及其系统发育分析

从山东潍坊池塘养殖的患有牙膏病的三疣梭子蟹(Portunus trituberculatus)中分离到1株病原菌(PX25),经回接感染证实为该病的病原菌。经生理生化试验及形态结构观察显示,该菌株革兰氏阴性,短杆状,直或稍弯曲,两端钝圆;固体培养基上培养后进行染色具有周生侧毛,液体培养基中培养后进行鞭毛染色具一极生单鞭毛;悬滴法观察PX25菌株具有很强的运动性。对其16SrRNA基因进行PCR扩增、测序和系统发育分析。结果表明,该菌株与溶藻弧菌亲缘关系最近,相似性达99.35%。综合菌体在形态、生理生化、API20NE与API20E自动鉴定结果、16S rRNA同源性等方面的特性,确认PX25为溶藻弧菌(Vibrio alginolyticus)。

Identification and phylogenetic analysis of a strain of Vibrio alginolyticus, a pathogen in Portunus trituberculatus with toothpaste disease

A pathogenic bacterium was isolated from Portunus trituberculatus ill with toothpaste disease. The bacteria were Gram-negative, and in a shape of short rod. The complete 16S rRNA gene sequence of the bacteria was determined following PCR amplification. The sequence was aligned with those available Vibrio and phylogenetic trees inferred using N-J method. The organism and the type strain of Vibrio alginolyticus consistently formed a monophyletic clade with a distant sequence similarity of 99.35 %. According to morphological features, biochemical and physiological characteristics, API 20NE and API 20E systems and 16S rRNA phylogenetic analysis, the pathogenic bacteria were identified as Vibrio alginolyticus.