title: Rapid Detection of Rifampicin- and Isoniazid-Resistant Mycobacterium tuberculosis using TaqMan Allelic Discrimination.
abstract: OBJECTIVE
  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).
  
  
  CONCLUSIONS
  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).
authors.affiliation: Department of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Davood
authors.initials: D
authors.lastname: Darban-Sarokhalil
authors.affiliation: Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad J
authors.initials: MJ
authors.lastname: Nasiri
authors.affiliation: Applied Microbiology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.
authors.forename: Abbas A I
authors.initials: AA
authors.lastname: Fooladi
authors.affiliation: Department of Microbiology, School of Medicine, Alborz University of Medical Sciences, Karaj, Iran.
authors.forename: Parvin
authors.initials: P
authors.lastname: Heidarieh
authors.affiliation: Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad M
authors.initials: MM
authors.lastname: Feizabadi
keywords: Mycobacterium tuberculosis; TaqMan allelic discrimination; minor groove binder (MGB); multidrug-resistant tuberculosis (MDR-TB); rapid detection