[Rd7 genotyping of M. tuberculosis strains isolated from patients with lung tuberculosis in different areas of Kazakhstan].

A three-primer PCR assay was designed for detection of possible deletions in the RD7 region of the Mycobacterium tuberculosis complex chromosome. The assay produced amplicons of different size depending on the presence or absence of the deletions. The PCR assay was applied to 176 isolates from patients with lung tuberculosis collected in different areas of Kazakhstan in summer 2004. The isolates were initially characterized by culture and biochemical tests. The RD7 genotyping results demonstrated no polymorphism and the absence of deletions in the RD7 genome region. Some strains were additionally characterized using PCR-RFLP analysis of gyrB and hsp64 genes. The RFLP-patterns obtained corresponded to the M. tuberculosis genotypes. The results of this work are consistent with certain previous studies, indicating population stability of the RD7 region in M. tuberculosis strains. Species characterization of the isolates shows that M. tuberculosis sensu stricto is the principal causative agent of human lung tuberculosis in Kazakhstan.