克雷伯菌16S rDNA和rpoB基因系统进化及序列特征分析  

Phylogenetic and characteristic analysis of 16S rDNA and rpoB gene sequence of Klebsiella

作　　者：郭晓琳[1] 王多春[2] 阚飙[2] 张燕敏[1] 张怡[1] 左颖[1] 魏来[3] 高燕[1] 

机构地区：[1]北京大学人民医院感染科,100044 [2]中国疾病预防控制中心传染病预防控制所传染病预防控制国家重点实验室,102206 [3]北京大学人民医院肝病研究所

出　　处：《中华微生物学和免疫学杂志》2009年第2期97-102,共6页Chinese Journal of Microbiology and Immunology

摘　　要：目的比较分析克雷伯菌属的种之间16S rDNA和rpoB系统进化发育关系和序列进化特征。方法选取经生化鉴定的克雷伯菌18株，提取菌株染色体作为模板，分别使用16S rDNA和rpoB通用引物扩增并测序16S rDNA和rpoB序列。与GenBank中目前已公布的8种克雷伯属菌株16S rDNA和rpoB序列各8条、除克雷伯菌外其他肠道菌株的16S rDNA和rpoB序列各9条一起，共计各35条16S rDNA和rpoB序列，在MEGA4．0中建立进化树并进行分群分析，使用DNAStar／MegAlign程序比较分析8种克雷伯菌的种间16S rDNA和rpoB序列变异碱基位点，并做分歧度分析。结果在所有受试的16SrDNA和rpoB的各35条序列中，16S rDNA和rpoB进化发育树都将克雷伯菌区分为3个群：分离的18株克雷伯菌中，15株肺炎亚种与GenBank中除产酸克雷伯菌和运动克雷伯菌外的其余6种克雷伯菌聚为一群（Ⅰ），其余3株克雷伯菌（FX246、FX280和FX286），经生化鉴定为产酸克雷伯菌，与GenBank中产酸克雷伯菌（DQ835530）聚为一群（Ⅱ）；而GenBank中的运动克雷伯菌单独聚为一群（Ⅲ）；进一步的分析，在rpoB进化发育树中，无论是Ⅰ群和Ⅱ群，还是Ⅰ群内的两个亚群，rpoB进化发育树的结点处自引导值都明显高于16S rDNA进化发育树；而且rpoB对产酸克雷伯菌的分群优于16S rDNA。对克雷伯菌的序列分析发现，16S rDNA序列存在41个碱基变异位点，有4个易变区，rpoB序列存在63个碱基变异位点，有1个易变区；克雷伯菌16S rDNA和rpoB的相似性分别为95．9％～100％和90．2％～100％。进一步的克雷伯菌种间序列分歧值分析，rpoB分歧值（0～10．6）高于16S rDNA（0～4．0）。结论克雷伯菌rpoB比16S rDNA具有更高的分歧度，在克雷伯菌属内种的分子分类和鉴定中，rpoB比16S rDNA基因更具优越性。Objective To compare and analyze the phylogenetic tree and sequence variant characteristics of KlebsieUa species between 16S rDNA and rpoB. Methods Eighteen isolates identified as genus Klebsiella （with 15 of K. pneumoniae and 3 of K. oxytoca） by automated biochemical tests were selected. DNA were extracted, 16S rDNA and rpoB genes were amplified and sequenced with Klebsiella 16S rDNA and rpoB primers. Together with already published 8 species of Klebsiella and 9 species of Enterobacteriaceae 16S rDNA and rpoB sequences from GenBank, totally 35 sequences of 16S rDNA and rpoB respectively, phylogenetic trees were constructed with MEGA 4.0 to the analysis of groups. DNAStar/MegAlign was used for comparison of variable regions of 16S rDNA and rpoB, with analysis of degree of divergent at the same time. Results As for all 35 sequences, both 16S rDNA and rpoB phylogenetic trees divided Klebsiella species into three groups, 15 of K. pneumoniae in this study and 6 of K. pneumoniae from GenBank （except for K. oxytoca and K. mobilis） cluster to group Ⅰ, K. oxytoca and K. mobilis were cluster to group Ⅱ and Ⅲ, respectively. In rpoB phylogenetic tree, no matter group Ⅰ and group Ⅱ, or subgroup within group Ⅰ , the bootstrap values in each node of rpoB phylogenetic tree is obviously higher than that of 16S rDNA. Moreover, as for cluster to K. oxytoca, rpoB is better than 16S rDNA. Analysis nucleic acid sequences of Klebsiella species, with 41 variable regions and 4 most significant regions were found within the Klebsiella 16S rDNA, while rpoB with 63 variable regions, and 1 most significant region. The similarity of 16S rDNA and rpoB within Klebsiella were 95.9% -100% and 90.2% -100% respectively. Further analysis divergent degree of 16S rDNA and rpoB within Klebsiella, the divergent value of rpoB （0-10.6） is higher than that of the 16S rDNA（0-4.0）. Conclusion As for molecular classification and identification within Klebsiella species, rpoB has more advantages than 16S rDNA.

关 键 词：克雷伯菌 16S RDNA RPOB 系统进化发育 序列特征 

分 类 号：R446.5[医药卫生—诊断学]