Evaluation of nitrate reductase assay for rapid detection of resistance to second-line drugs in Mycobacterium tuberculosis in a tertiary care hospital.
The present study evaluated nitrate reductase assay (NRA) for rapid detection of resistance to 5 second-line drugs: kanamycin, ethionamide, ofloxacin, cycloserine, and para-aminosalicylic acid. Eighty-six multidrug-resistant clinical isolates of Mycobacterium tuberculosis were used to compare NRA with proportion method for rapid detection of resistance to second-line drugs. The sensitivity of the NRA for different drugs ranged from 86.4% to 100%, whereas the specificity ranged from 98.4% to 100%. Excellent agreement was found between the 2 tests with respect to their κ values. For 63% of the isolates, the results were available in 14 days (turnaround time). The NRA is a rapid, accurate, simple, and inexpensive method for detection resistance to second-line drugs. This method may become an appropriate alternative method, especially for the resource poor settings.
Visalakshi
Potharaju
P
Department of Microbiology, LRS Institute of Tuberculosis and Respiratory Disease, New Delhi, India. pvishala@yahoo.com
Arora
Jyoti
J
Behera
Digamber
D
D000995:Antitubercular Agents / Q000494:pharmacology*; D024901:Drug Resistance, Multiple, Bacterial; D006761:Hospitals; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods; D009169:Mycobacterium tuberculosis / Q000187:drug effects*; D050901:Nitrate Reductase / Q000378:metabolism*; D012680:Sensitivity and Specificity
D000995:Antitubercular Agents; D050901:Nitrate Reductase