Computationalstudy of housekeeping genes in differentiation of Non-tuberculosis mycobacteria

Non-tuberculosis mycobacteria is acid-fast bacteria that lives in environmental sources such as: water, soil, dust, milk and decaying vegetables. Based on Runyon’s classification these bacteria classified in tow group of slow and rapid growing mycobacteria that both of them isolated from clinical specimens.The purpose of this study is evaluation of three housekeeping genes in identification and differentiation of non-tuberculosis mycobacteria. In our study we obtained 16S rRNA, rpoB and hsp65 sequences of twenty two slow and rapid growing mycobacteria from Genebank (www.ncbi.nlm.nih.gov). Then this sequences aligned and transferred to MEGA 5.0 program. Finally phylogenetic relationships were determined by constructing 16S rRNA, rpoB and hsp65 genes tree using the neighbor-joining method with Kimura 2-Parameter model. Results and conclusion: Phylogenetic analysis based on 16S rRNA, rpoB and hsp65 gene sequences indicated that except of rpoB gene, other genes cannot identificated and separate of some species. Also we found that for identification both of rapid growth mycobacteria (RGM) and slow growth mycobacteria (SGM)rpoB gene is the best option.due to findings of this study, it seems that for appropriate and accurate identification of non-tuberculosis mycobacteria we must studied rpoB and hsp65 genes simultaneously