知识与财富的链接
从患病养殖大黄鱼分离到3株病原菌H040823-1、H050704-1、H050815-1,经常规生理生化鉴定均属于弧菌属的种类,API 20E快速鉴定菌株H040823-1为副溶血弧菌(Vibrio parahaemolyticus),菌株H050815-1为溶藻弧菌(V.alginolyticus),菌株H050704-1不在API 20E鉴定谱内.为了进一步确定其分类地位,测定了3株病原菌的16S rRNA和HSP60(heat shock protein,HSP60)基因部分序列.16S RNA基因系统进化分析表明,3株病原菌与副溶血弧菌、哈维氏弧菌、溶藻弧菌亲缘关系较近,相互之间同源性均大于96.9%,差异不明显.HSP60基因序列分析表明,菌株H040823-1、H050704-1、H050815-1的HSP60基因序列分别与V.parahaemolyticus(AF230951)、V.harveyi (EU036994)、V.alginolyticus(DQ664545)的同源性最高,分别为96.7%、99.8%和98.0%,而与其他弧菌HSP60基因的同源性均低于91.9%,3株病原菌相互之间同源性低于92.3%,差异显著.HSP60基因构建的系统进化树表明,H040823-1、H050704-1、H050815-1分别与V.parahaemolyticus、V harveyi、V alginolyticus聚类.综合以上结果,菌株H040823-1、H050704-1、H050815-1可分别鉴定为副溶血弧菌、哈维氏弧菌、溶藻弧菌.结果表明,HSP60基因比16S rRNA基因更适合用于海水鱼类致病性弧菌种间的分类研究.
Three vibrio strains of pathogenic bacteria, H040823-1, H050704-1 and H050815-1 were isolated from dis- eased cultured large yellow croaker (Pseudosciaena crocea Richardson), and identified as Vibrio in regular physiological and biochemical analyses. With API 20E technique, H040823-1 was recognized as V. parahaemolyticus, H050815-1 as V. alginolyticus, while H050704-1 could not be identified. Therefore, 16S rRNA and the genes partial sequences of heat shock protein (HSP60) were further determined. The three strains were very similar to Vibrio parahaemolyticus, V. harveyi and V. alginolyticus in terms of 16S rRNA gene sequence. Sequences analysis of HSP60 genes showed that the nucleotide ho- mology of H040823-1 to V. parahaemolyticus (AF230951), H050704-1 to V. harveyi (EU036994), and H050815-1 to V. alginolyticus (DQ664545) was 96.7%, 99.8% and 98.0%, respectively, and to other Vibrio species, below 91.9%. The nu- cleotide homology of HSP60 genes among the three isolates were less than 92.3%. Phylogenetic tree of Vibrio based on HSP60 genes showed that strains H040823-1, H050704-1 and H050815-1 clustered together with V. parahaemolyticus, V. harveyi and V. alginolyticus, respectively. Therefore, the strains H040823-1, H050704-1, and H050815-1 were identified as V. parahaemolyticus, V. harveyi and V. alginolyticus, respectively. Taxonomic classification of marine Vibrios with HSP60 gene instead of 16S rRNA gene was proved a better approach.
