title: Multiplex allele-specific polymerase chain reaction for detection of isoniazid resistance in Mycobacterium tuberculosis.
abstract: METHODS
  Pham Ngoc Thach Tuberculosis Reference Hospital, Ho Chi Minh City, Viet Nam.
  
  
  METHODS
  A multiplex allele-specific polymerase chain reaction (MAS-PCR) was developed to detect mutations at the two most common sites responsible for isoniazid (INH) resistance in Mycobacterium tuberculosis: katG315 and inhA-15. The MAS-PCR is able to detect rare mutations at katG315, in addition to katG S315T. Conventional phenotypic proportion drug susceptibility testing on Löwenstein-Jensen media was used as a gold standard to compare the sensitivity and specificity of the commercial MTBDRplus line-probe assay and the MAS-PCR in 100 INH-resistant and 50 INH-susceptible isolates collected consecutively at Pham Ngoc Thach Hospital reference laboratory.
  
  
  RESULTS
  The sensitivity and specificity on culture isolates were 90% (n = 90/100, 95%CI 0.83-0.94) and 100% (n = 50/50, 95%CI 0.93-1.0), respectively, for the MAS-PCR and the MTBDRplus assay.
  
  
  CONCLUSIONS
  The MAS-PCR described here represents an alternative method for rapid screening for INH resistance in M. tuberculosis isolates.
authors.affiliation: University of Oxford Clinical Research Unit, Wellcome Trust Major Overseas Programme, Hospital for Tropical Diseases, Ho Chi Minh City, Viet Nam.
authors.forename: D Q
authors.initials: DQ
authors.lastname: Tho
authors.forename: N T N
authors.initials: NT
authors.lastname: Lan
authors.forename: N V V
authors.initials: NV
authors.lastname: Chau
authors.forename: J
authors.initials: J
authors.lastname: Farrar
authors.forename: M
authors.initials: M
authors.lastname: Caws
mesh_terms: D000483:Alleles; D000995:Antitubercular Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics; D002374:Catalase / Q000235:genetics; D017931:DNA Primers; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D006801:Humans; D007538:Isoniazid / Q000494:pharmacology*; D060885:Multiplex Polymerase Chain Reaction / Q000191:economics / Q000379:methods*; D009154:Mutation; D009169:Mycobacterium tuberculosis / Q000187:drug effects / Q000235:genetics*; D010088:Oxidoreductases / Q000235:genetics; D012680:Sensitivity and Specificity; D017421:Sequence Analysis; D018088:Tuberculosis, Multidrug-Resistant / Q000175:diagnosis / Q000188:drug therapy; D014744:Vietnam
chemical_list: D000995:Antitubercular Agents; D001426:Bacterial Proteins; D017931:DNA Primers; D010088:Oxidoreductases; D002374:Catalase; C480353:katG protein, Mycobacterium tuberculosis; C085257:InhA protein, Mycobacterium; D007538:Isoniazid