Characterization of Molecular Evolution in Multi-Drug Resistant of Mycobacterium tuberculosis by rpoB Gene in Patient with Active Pulmonary Tuberculosis from Iranian Isolates

摘要

This is the first genetic biodiversity study of Mycobacterium tuberculosis in Iran. Thus, we investigatedthe genetic patterns of strains isolated in the first survey of anti-tuberculosis drug-resistance by rpoB geneas part of the Global Project of Anti-tuberculosis Drug Resistance Surveillance (IAU, Iran). A 411-bp fragmentof the rpoB gene, containing the sequence of the 81-bp rpoB fragment, was amplified by PCR and therpoB gene fragments of tuberculosis strains were sequenced using the Amersham auto sequencer. For analysingtree evolution used method UPGMA and Neighbour-Joining. Clinical isolates (34/163) were analyzedby using sequencing gene rpoB and genotyped by program MEGA. The results were compared with theinternational database. Multi-drug resistant (MDR) was 14% in never treated patients and 8% in previouslytreated patients. Mutations in rpoB gene and katG genes were detected in 95% and 84% of the MDRstrains, respectively. Two clusters were found to be identical by the four different analysis methods, presumablyrepresenting cases of recent transmission of MDR tuberculosis. The other strains are divided into2 groups: group A – similar to the standard and Eastern strains (China, Taiwan) and group B – strains ofanother genotype. They are grouped separately on the dendrogram and became prevalent in Iran (they arecalled Iranian residential strains). This study gives a first overview of the M. tuberculosis strains circulatingin Iran during the first survey of anti-tuberculosis drug-resistance. It may aid in the creation of a nationaldatabase that will be a valuable support for further studies