Objectives: Multidrug-resistant tuberculosis (MDR-TB) is a global problem that many countries are challenged with. Rapid and accurate detection of MDR-TB is critical for appropriate treatment and controlling of TB. The aim of the present study was to evaluate the TaqMan allelic discrimination without minor groove binder (MGB) as a rapid, efficient, and low-cost method for detection of drug resistant strains of Mycobacterium tuberculosis. Methods: A total of 112 M. tuberculosis isolates from cases with diagnosed TB were subjected to drug susceptibility testing (DST), using the proportion method. Resistant isolates were tested for characterization of mutations in the rpoB and KatG genes by TaqMan genotyping. Results: Of 112 M. tuberculosis isolates for which DST was performed, three, one, and two isolates were MDR, rifampin (RIF) resistant, and isoniazid (INH) resistant, respectively. According to the threshold cycle (Ct) and curve pattern of mutants, TaqMan probes detect all of the mutations in the analyzed genes (katG 315, AGC→ACC, rpoB 531, TCG→TTG, and rpoB 531, TCG→TGG). Conclusion The present study suggests that drug-resistant strains of M. tuberculosis can be detected by pattern’s curve or Ct with TaqMan probes without MGB in real-time polymerase chain reaction (PCR).

We herein report a case in which the recently characterized species Mycobacterium monacense was isolated from the sputum of an Iranian patient. This case represents the first isolation of M. monacense from Iran. The isolate was identified by conventional and molecular techniques. Our findings show that M. monacense infection is not restricted to developed countries.
Bacterial Proteins/genetics ; Chaperonin 60/genetics ; Chronic Disease ; Female ; Humans ; Iran ; Lung Diseases/diagnosis/*microbiology ; Middle Aged ; Mycobacterium/classification/*genetics/isolation & purification ; Mycobacterium Infections/*microbiology/pathology ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; Sputum/microbiology