title: Utility of GenoType MTBDRplus assay in rapid diagnosis of multidrug resistant tuberculosis at a tertiary care centre in India.
abstract: OBJECTIVE
  Molecular methods which allow rapid detection of tuberculosis as well as drug resistance directly from clinical samples have become the most popular diagnostic methodology with the emergence of multidrug resistant tuberculosis. The aim of the present study was to evaluate the performance of a line probe assay, GenoType MTBDRplus for the rapid detection of Mycobacterium tuberculosis and mutations causing rifampicin and INH resistance directly in smear positive pulmonary specimens and also in M. tuberculosis isolates grown from various clinical specimens.
  
  
  METHODS
  The MTBDRplus assay was done directly on 37 smear positive pulmonary specimens and also on 69 M. tuberculosis isolates obtained by rapid automated culture using Bact/Alert 3D. The results were compared with phenotypic drug susceptibility testing (1% proportion method) using Bact/Alert 3D.
  
  
  RESULTS
  The sensitivity and specificity for detection of resistance to rifampicin was 100% and 97.3%, and to INH was 91.9% and 98.4%, respectively, in comparison with the phenotypic drug susceptibility testing.
  
  
  CONCLUSIONS
  MTBDRplus assay had good sensitivity and specificity with turn around time of less than 48 hours. It may be a useful tool for rapid detection of multidrug resistant tuberculosis at a tertiary care centre.
authors.affiliation: Department of Clinical Microbiology and Immunology, Sir Ganga Ram Hospital, New Delhi - 110 060, India.
authors.forename: R
authors.initials: R
authors.lastname: Raveendran
authors.forename: C
authors.initials: C
authors.lastname: Wattal
authors.forename: J K
authors.initials: JK
authors.lastname: Oberoi
authors.forename: N
authors.initials: N
authors.lastname: Goel
authors.forename: S
authors.initials: S
authors.lastname: Datta
authors.forename: K J
authors.initials: KJ
authors.lastname: Prasad
mesh_terms: D000995:Antitubercular Agents / Q000494:pharmacology*; D001431:Bacteriological Techniques / Q000379:methods*; D004269:DNA, Bacterial / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial; D005838:Genotype; D006761:Hospitals; D006801:Humans; D007194:India; D007538:Isoniazid / Q000494:pharmacology; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D020125:Mutation, Missense; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification*; D012293:Rifampin / Q000494:pharmacology; D012680:Sensitivity and Specificity; D018088:Tuberculosis, Multidrug-Resistant / Q000175:diagnosis*
chemical_list: D000995:Antitubercular Agents; D004269:DNA, Bacterial; D007538:Isoniazid; D012293:Rifampin