Rapid detection of multidrug-resistant Mycobacterium tuberculosis using the malachite green decolourisation assay


Creative Commons License

Coban A. Y., UZUN M.

MEMORIAS DO INSTITUTO OSWALDO CRUZ, cilt.108, sa.8, ss.1021-1023, 2013 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 108 Sayı: 8
  • Basım Tarihi: 2013
  • Doi Numarası: 10.1590/0074-0276130697
  • Dergi Adı: MEMORIAS DO INSTITUTO OSWALDO CRUZ
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.1021-1023
  • Anahtar Kelimeler: Mycobacterium tuberculosis, malachite green decolourisation assay, susceptibility testing, isoniazid, rifampicin, NITRATE REDUCTION ASSAY, RIFAMPICIN RESISTANCE, XPERT MTB/RIF
  • Akdeniz Üniversitesi Adresli: Hayır

Özet

Early detection of drug resistance in Mycobacterium tuberculosis isolates allows for earlier and more effective treatment of patients. The aim of this study was to investigate the performance of the malachite green decolourisation assay (MGDA) in detecting isoniazid (INH) and rifampicin (RIF) resistance in M. tuberculosis clinical isolates. Fifty M. tuberculosis isolates, including 19 multidrug-resistant, eight INH-resistant and 23 INH and RIF-susceptible samples, were tested. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and agreement of the assay for INH were 92.5%, 91.3%, 92.5%, 91.3% and 92%, respectively. Similarly, the sensitivity, specificity, PPV, NPV and agreement of the assay for RIF were 94.7%, 100%, 100%, 96.8% and 98%, respectively. There was a major discrepancy in the tests of two isolates, as they were sensitive to INH by the MGDA test, but resistant by the reference method. There was a minor discrepancy in the tests of two additional isolates, as they were sensitive to INH by the reference method, but resistant by the MGDA test. The drug susceptibility test results were obtained within eight-nine days. In conclusion, the MGDA test is a reliable and accurate method for the rapid detection of INH and RIF resistance compared with the reference method and the MGDA test additionally requires less time to obtain results.