鳗鲡病原菌16S rRNA基因序列测定及系统进化分析

Sequencing and Phylogenetic Analysis of 16S rRNA Genes of Pathogenic Bacteria Isolated from Cultivated Eels

对从福建省不同鳗鲡养殖场发病鳗鲡肝脏中分离并经感染证实的35株致病菌的16S rRNA基因进行序列测定和系统进化分析。用CTAB法提取各菌株DNA,以细菌16S rDNA通用引物进行PCR扩增,用限制性片段长度多态性分析1、6S rDNA序列分析和系统进化分析对其进行分子鉴定,构建系统进化树。结果表明:35株致病菌分别属于γ-变形菌纲和厚壁菌门2大类群的6个属和1个科,主要种类是气单胞菌属的嗜水气单胞菌、维氏气单胞菌、简氏气单胞菌和豚鼠气单胞菌等,占63%;其次是芽孢杆菌属细菌;少量为鲁氏耶尔森菌、弗氏柠檬酸杆菌、克雷伯氏菌属、假交替单胞菌属细菌和肠杆菌科细菌。

Thirty five pathogenic bacteria verified by artificial infection from the livers of diseased eels were subjected to sequencing and phylogenetic analysis.DNA was extracted by CTAB method from each isolate,the 16S rRNA genes were amplified using universal bacterial primers,and then the 35 isolates were identified by restriction fragment length polymorphism（RFLP） analysis,sequences analysis and phylogenetic analysis of the 16S rRNA genes.The phylogenetic tree was constructed.The results indicated that these pathogenic bacteria belong to six genera and one family of two major groups（γ-Proteobacteria and Firmicutes）.The Aeromonas genus is predominant（occupied 63%）,including Aeromonas hydrophila,Aeromonas veronii,Aeromonas jandaei,and Aeromonas punctata.The Bacillus genus is second dominant.The rest are Yersinia ruckeri,Citrobacter freundii,and species of klebsiella geuns,Pseudoalteromonas genus and Enterobacteriaceae family.