title: Evaluation of efficiency of nested multiplex allele-specific PCR assay for detection of multidrug resistant tuberculosis directly from sputum samples.
abstract: For an effective control of tuberculosis, rapid detection of multidrug resistant tuberculosis (MDR-TB) is necessary. Therefore, we developed a modified nested multiplex allele-specific polymerase chain reaction (MAS-PCR) method that enables rapid MDR-TB detection directly from sputum samples. The efficacy of this method was evaluated using 79 sputum samples collected from suspected tuberculosis patients. The performance of nested MAS-PCR method was compared with other MDR-TB detection methods like drug susceptibility testing (DST) and DNA sequencing. As rifampicin (RIF) resistance conforms to MDR-TB in greater than 90% cases, only the presence of RIF-associated mutations in rpoB gene was determined by DNA sequencing and nested MAS-PCR to detect MDR-TB. The concordance between nested MAS-PCR and DNA sequencing results was found to be 96·3%. When compared with DST, the sensitivity and specificity of nested MAS-PCR for RIF-resistance detection were determined to be 92·9 and 100% respectively.
  
  
  CONCLUSIONS
  For developing- and high-TB burden countries, molecular-based tests have been recommended by the World Health Organization for rapid detection of MDR-TB. The results of this study indicate that, nested MAS-PCR assay might be a practical and relatively cost effective molecular method for rapid detection of MDR-TB from suspected sputum samples in developing countries with resource poor settings.
authors.affiliation: Department of Microbiology, University of Dhaka, Dhaka, Bangladesh.
authors.forename: S K
authors.initials: SK
authors.lastname: Mistri
authors.affiliation: Department of Microbiology, University of Dhaka, Dhaka, Bangladesh.
authors.forename: M
authors.initials: M
authors.lastname: Sultana
authors.affiliation: National Tuberculosis Reference Laboratory, NIDCH, Dhaka, Bangladesh.
authors.forename: S M M
authors.initials: SM
authors.lastname: Kamal
authors.affiliation: Department of Microbiology, University of Dhaka, Dhaka, Bangladesh.
authors.forename: M M
authors.initials: MM
authors.lastname: Alam
authors.affiliation: National Tuberculosis Reference Laboratory, NIDCH, Dhaka, Bangladesh.
authors.forename: F
authors.initials: F
authors.lastname: Irin
authors.affiliation: Department of Microbiology, University of Dhaka, Dhaka, Bangladesh.
authors.forename: J
authors.initials: J
authors.lastname: Nessa
authors.affiliation: Department of Microbiology, University of Dhaka, Dhaka, Bangladesh.
authors.forename: C R
authors.initials: CR
authors.lastname: Ahsan
authors.affiliation: Department of Microbiology, University of Dhaka, Dhaka, Bangladesh.
authors.forename: M
authors.initials: M
authors.lastname: Yasmin
mesh_terms: D000328:Adult; D000483:Alleles; D000995:Antitubercular Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics; D012321:DNA-Directed RNA Polymerases / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D005260:Female; D006801:Humans; D007538:Isoniazid / Q000494:pharmacology; D060885:Multiplex Polymerase Chain Reaction / Q000379:methods; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000235:genetics*; D012293:Rifampin / Q000494:pharmacology; D017422:Sequence Analysis, DNA; D013183:Sputum / Q000382:microbiology*; D018088:Tuberculosis, Multidrug-Resistant / Q000175:diagnosis* / Q000235:genetics* / Q000382:microbiology
chemical_list: D000995:Antitubercular Agents; D001426:Bacterial Proteins; C505805:rpoB protein, Mycobacterium tuberculosis; D012321:DNA-Directed RNA Polymerases; D007538:Isoniazid; D012293:Rifampin
keywords: Mycobacterium tuberculosis; multidrug resistant tuberculosis; multiplex allele-specific PCR; rifampicin; sputum