Antimicrobial Sensitivity Pattern of Clinical Isolates of Mycobacterium Tuberculosis: A-Retrospective Study from a Reference Laboratory in Pakistan

Abstract

Objective: To determine the sensitivity pattern of first line anti-tuberculosis drugs against clinical isolates of Mycobacterium tuberculosis (MTB) in our settings. Place and duration: Department of Microbiology, Armed Forces Institute of Pathology Rawalpindi, Pakistan, from January 2010 through December 2012. Materials & Methods: Samples received during the study period were processed on MGIT 960 system for MTB culture and drug susceptibility testing (DST) was performed for first line antituberculosis drugs, namely rifampicin (RIF), isoniazid (INH), streptomycin (STR) and ethambutol (ETH). MTB ATCC 25177 was used as control strain. Results: A total of 4050 samples were tested on MGIT 960 System, out of which 689(17%) were culture positive. Out of these culture positive cases, 303(44%) were pansensitive, 52(7.5%) pan-resistant, 84(12.2%) sensitive to one drug only, 171(24.8%) resistant to one drug only and 49(7.1%) were resistant to 2 drugs other than MDR. 132(19.16%) cases were multidrug resistant (MDR). Conclusion: Resistance to first line anti-tuberculosis drugs is alarming. Our results highlight the importance of drug susceptibility testing of MTB isolates against first line anti-tuberculosis drugs in an endemic country, so as to properly manage tuberculosis patients.