Emerging Pathogens Institute, University of Florida, 2055 Mowry Rd., Gainesville, FL 32611, USA.
J Clin Microbiol. 2011 Jan;49(1):144-53. doi: 10.1128/JCM.00957-10. Epub 2010 Nov 3.
To identify loci useful for species identification and to enhance our understanding of the population structure and genetic variability of the genus Mycobacterium, we conducted a multiple-genome comparison of a total of 27 sequenced genomes in the suborder of Corynebacterineae (18 from the Mycobacterium genus, 7 from the Corynebacterium genus, 1 each from the Nocardia and Rhodococcus genera). Our study revealed 26 informative loci for species identification in Mycobacterium. The sequences from these loci were used in a phylogenetic analysis to infer the evolutionary relations of the 18 mycobacterial genomes. Among the loci that we identified, rpoBC, dnaK, and hsp65 were amplified from 29 ATCC reference strains and 17 clinical isolates and sequenced. The phylogenetic trees generated from these loci show similar topologies. The newly identified dnaK locus is more discriminatory and more robust than the widely used hsp65 locus. The length-variable rpoBC locus is the first intergenic locus between two protein-encoding genes being used for mycobacterial species identification. A multilocus sequence analysis system including the rpoBC, dnaK, and hsp65 loci is a robust tool for accurate identification of Mycobacterium species.
为了鉴定用于物种鉴定的基因座，并增进我们对分枝杆菌属的种群结构和遗传变异的理解，我们对棒状杆菌亚目（分枝杆菌属 18 株、棒状杆菌属 7 株、诺卡氏菌属和红球菌属各 1 株）的总共 27 个已测序基因组进行了多次基因组比较。我们的研究揭示了分枝杆菌属中 26 个用于物种鉴定的信息性基因座。这些基因座的序列被用于系统发育分析，以推断 18 株分枝杆菌基因组的进化关系。在我们鉴定的基因座中，rpoBC、dnaK 和 hsp65 从 29 株 ATCC 参考株和 17 株临床分离株中扩增并测序。这些基因座生成的系统发育树显示出相似的拓扑结构。新鉴定的 dnaK 基因座比广泛使用的 hsp65 基因座更具区分性和稳健性。可变长度 rpoBC 基因座是第一个用于分枝杆菌物种鉴定的两个编码蛋白基因之间的基因间基因座。包含 rpoBC、dnaK 和 hsp65 基因座的多位点序列分析系统是准确鉴定分枝杆菌物种的有力工具。
