Sensitivity Pattern of Second Line Anti-Tuberculosis Drugs against Clinical Isolates of Multidrug Resistant Mycobacterium Tuberculosis

Objective: To determine the current sensitivity pattern of second line anti-tuberculosis drugs against clinical isolates of Multidrug Resistant Mycobacterium tuberculosis [MDR-TB]. Study Design: A cross-sectional study. Place and Duration of Study: Department of Microbiology, Armed Forces Institute of Pathology [AFIP], Rawalpindi, from November 2011 to April 2013. Methodology: Samples received during the study period were processed on BACTEC MGIT 960 system for Mycobacterium tuberculosis [MTB] culture followed by first line drugs susceptibility testing of culture proven MTB isolates. On the basis of resistance to rifampicin and isoniazid, 100 clinical isolates of MDR-TB were further subjected to susceptibility testing against amikacin [AMK], capreomycin [CAP], ofloxacin [OFL] and ethionamide [ETH] as per st and ard BACTEC MGIT 960 instructions. Results: Out of 100 MDR-TB isolates, 62% were from male patients and 38% from female patients. 97% were sensitive to AMK, 53% to OFL, 87% to CAP; and 87% were sensitive to ETH. Conclusion: The majority of the MDR-TB isolates showed excellent sensitivity against AMK, CAP and ETH. However, sensitivity of MDR-TB isolates against fluoroquinolones like OFL was not encouraging. Key Words: Multidrug resistant tuberculosis. Mycobacteria growth indicator tube. Second line anti-tuberculosis drugs. Amikacin. Capreomycin. Ethionamide