Drug Resistance Pattern in the Clinical Isolates of Pulmonary Tuberculosis

Multidrug-resistant tuberculosis (MDR-TB) is a major public health threat, especially in a country like India, which carries the highest global burden of tuberculosis (TB). TB is caused by Mycobacterium tuberculosis (MTB); the bacteria possess multiple mechanisms that provide it both intrinsic and acquired resistance to current anti-TB drugs. In the current treatment regimen followed for TB, rifampicin and isoniazid are the major drugs given in the first line of treatment. Fluoroquinolones and aminoglycosides are the second line drugs given in case the MTB is resistant to first line drugs. Acquired resistance is mainly due the exposure of MTB to suboptimal concentration of drugs, either due to inadequate treatment given by the medical practitioner or due to the discontinuous treatment regimen followed by patients. Treating drug susceptible TB requires a treatment regimen of almost 6 months which increases significantly from 9 months to 24 months in case of drug resistant cases. In the study conducted we determined the resistance patterns to first and second line anti-TB drugs and the frequency of MDR-TB. Contemplating the drug resistance pattern of MTB will help understanding the epidemiological parameters involved.