In Vitro efficacy of ethionamide and clarithromycin in mycobacterium tuberculosis isolates

ABSTRACT

To determine the sensitivity of clinical isolates of Mycobacterium tuberculosis isolates against ethionamide, and clarithromycin. Cross-sectional study. Department of Microbiology, Armed Forces Institute of Pathology [AFIP] Rawalpindi from June 2003 to June 2004. All routine clinical samples received for acid fast bacilli [AFB] culture and yielding positive growth on Lowenstien Jensen medium and Bactec 460 were included in the study. The isolates were from sputum [n=70], bronchioalveolar lavage [n=10], fine needle aspiration [n=6], lymph nodes [n=7], pleural fluid [n=4], endometrium [n=3]. After the identification of M. tuberculosis [MTB] sensitivity was performed against first-line antituberculosis drugs. Then susceptibility of M. tuberculosis isolates against ethionamide and clarithromycin was performed on LJ medium. Mycobacterium H37Rv was used as control strain. Results were interpreted using resistance ratio method. Out of 100 M. tuberculosis isolates, sensitivity to ethionamide was 93% and 9% to clarithromycin. Clarithromycin when used alone is ineffective as antituberculosis drug but its efficacy in combination needs to be tested. However ethionamide may be used as an alternative antituberculosis drug