Analysis of drug susceptibility in Mycobacterium tuberculosis isolated from Thiruvananthapuram using Alamar Blue assay
Kumar, R.A.; Paul, K.L.; Indulakshmi, R.; Manju, Y.K.; Kumar, K.V.; Ayyappan, P.; Joshi, M.; Mundayoor, S.
Current Science 80(1): 70-73
2001
ISSN/ISBN: 0011-3891 Document Number: 255024
Tuberculosis (TB) is caused by Mycobacterium tuberculosis and the control of the disease is hampered by widespread emergence of drug resistance in this pathogen. An early information on drug susceptibility would greatly facilitate an effective treatment of TB. Seventy-eight isolates of M. tuberculosis were obtained from TB patients from Thiruvananthapuram over a period of about 18 months. Resistance and susceptibility of these isolates to four frontline drugs were assayed using Alamar Blue, an oxidation-reduction dye. Thirty-six per cent of the isolates were susceptible to all the four drugs used, 21.8% were resistant to isoniazid, 8.9% to ethambutol and 2.6% to rifampicin. None was found resistant to streptomycin alone. Multidrug resistance (resistance to at least rifampicin and isoniazid) was found in 7.7% of the isolates. The remaining ones were resistant to combinations of two or more of the drugs. Alamar Blue-based assay promises to be an economical and fast method to determine drug susceptibility and resistance of M. tuberculosis to aid effective drug therapy.