缢蛏致病菌假单胞菌的分子生物学分析

Molecular Biological Analysis of a Pseudomonas sp from Pathogenic Sinvnovacula constricta

从患病缢蛏(Sinvnovacula constricta)中分离到一株病原菌,命名为1#菌株。采用传统方法提取菌株DNA,PCR扩增其16SrDNA基因片段、测序,得到该菌基因片段序列长度为1438bp。用M egA lign软件进行比对5种不同种细菌基因序列,构建进化树。16SrDNA产物序列分析结果表明:该菌株的16SrDNA的核苷酸序列与多株假单胞菌(Pseud-om onas sp)的同源性为99%,在系统发育树上构成一个分支。在细菌系统发育分类学上,该菌株属于假单胞属,但与已定名的假单胞菌有一定的差异,与几种未定名的假单胞菌的亲缘关系最接近。对其分类地位的最后确定还需进一步的系统发育学分析。

There was one pathogenic strain isolated from Sinvnovacula constricta, which was named 1 #. The DNA was extracted with the tradition method. The 16SrDNA fragment was amplified from strain 1# by PCR. Its gene fragments contains 1438bp. Using the MegAlign software, the homologus sequences were compared and the molecular phylogenetic tree was constructed. The 16SrDNA sequence homology and phylogenetic analysis indicated that strain 1# shared 99% 16SrDNA sequence homology with Pseudomonas sp and these sequences constituted a branch in phylogenetie tree. In the phylogenetic framework of bacterial classification, the strain 1 # belongs to Pseudomonas sp. But the results showed that the strain 1 # was differentiated from any of the named Pseudomonas species. Based on the phylogenetie analysis, the strain 1 # exhibited the highest levels of similarity to Pseudomonas sp. Therefore, their taxonomic placement needs more information on genes level.