BACKGROUND: There is a growing need to develop rapid laboratory research methods to counter the menace of drug resistant tuberculosis (MDR-TB) cases worldwide especially in developing countries. The present study was undertaken to investigate the type and frequency of rpoB and katG mutations in rifampicin (RIF) and isoniazid (INH) resistant strains respectively of Mycobacterium tuberculosis (MTB) circulating in Northern India and to explore the utility of multiplex-allele-specific (MAS)-PCR assay for detection of drug-resistant MTB isolates in low resource set up. METHODS: Phenotypic and genotypic drug susceptibility testing (DST) was performed on 354 MTB isolates. RESULTS: Mutation in rpoB gene was found most frequently at codons 531, 526 and 516 (59.83%, 45.29% and 22.22%, respectively). Further, combinations of 2-3 point mutations were also observed in 19.66% of RIF-resistant MTB strains. The frequency of mutations in katG gene was found at codon 315 among 82.95% of the INH-resistant MTB isolates. MAS-PCR detected rpoB and katG mutations in phenotypically resistant isolates with sensitivities of 93% and 83% respectively. CONCLUSION: MAS-PCR assays can be used for rapid detection of drug-resistant TB strains in routine diagnostic practice, enabling early administration of appropriate treatment regimens to the affected patients.
BACKGROUND: There is a growing need to develop rapid laboratory research methods to counter the menace of drug resistant tuberculosis (MDR-TB) cases worldwide especially in developing countries. The present study was undertaken to investigate the type and frequency of rpoB and katG mutations in rifampicin (RIF) and isoniazid (INH) resistant strains respectively of Mycobacterium tuberculosis (MTB) circulating in Northern India and to explore the utility of multiplex-allele-specific (MAS)-PCR assay for detection of drug-resistant MTB isolates in low resource set up. METHODS: Phenotypic and genotypic drug susceptibility testing (DST) was performed on 354 MTB isolates. RESULTS: Mutation in rpoB gene was found most frequently at codons 531, 526 and 516 (59.83%, 45.29% and 22.22%, respectively). Further, combinations of 2-3 point mutations were also observed in 19.66% of RIF-resistant MTB strains. The frequency of mutations in katG gene was found at codon 315 among 82.95% of the INH-resistant MTB isolates. MAS-PCR detected rpoB and katG mutations in phenotypically resistant isolates with sensitivities of 93% and 83% respectively. CONCLUSION: MAS-PCR assays can be used for rapid detection of drug-resistant TB strains in routine diagnostic practice, enabling early administration of appropriate treatment regimens to the affected patients.
Authors: G Canetti; W Fox; A Khomenko; H T Mahler; N K Menon; D A Mitchison; N Rist; N A Smelev Journal: Bull World Health Organ Date: 1969 Impact factor: 9.408
Authors: J D van Embden; M D Cave; J T Crawford; J W Dale; K D Eisenach; B Gicquel; P Hermans; C Martin; R McAdam; T M Shinnick Journal: J Clin Microbiol Date: 1993-02 Impact factor: 5.948
Authors: Igor Mokrousov; Olga Narvskaya; Elena Limeschenko; Tatiana Otten; Boris Vyshnevskiy Journal: J Clin Microbiol Date: 2002-05 Impact factor: 5.948
Authors: K Srivastava; R Das; P Jakhmola; P Gupta; D S Chauhan; V D Sharma; H B Singh; A S Sachan; V M Katoch Journal: Indian J Med Res Date: 2004-08 Impact factor: 2.375