TITLE:
Drug Susceptibility Testing of Mycobacteria Isolated from Humans and Cattle from Selected Sites of Ethiopia
AUTHORS:
Mekonnen Tadesse, Gobena Ameni, Kassu Desta
KEYWORDS:
M. tuberculosis, M. bovis, Drug Resistance, Tuberculosis
JOURNAL NAME:
Journal of Tuberculosis Research,
Vol.2 No.3,
September
3,
2014
ABSTRACT: Background: The effectiveness of a standard anti-tuberculosis (TB) treatment regimen correlates with in vitro drug susceptibility pattern of the infecting tubercle bacilli. The results of the drug susceptibility tests help select a proper treatment regimen or modify treatment regimen for a better management of patients and surveillance and timely control of the spread of the drug resistant TB in the community. Treatment of drug resistant TB is costly, and the outcomes, including survivorship, can be poor. As the result, the drug susceptibility test has become more important than ever. Objective: To determine the drug-susceptibility pattern of M. tuberculosis and M. bovis isolated from selected sites of Ethiopia. Methods: The conventional indirect Löwenstein-Jensen (L-J) proportion method was used to detect the drug susceptibility pattern of 29 isolates of M. tuberculosis and 21 isolates of M. bovis to four anti-TB drugs (streptomycin, rifampicin, isoniazid and ethambutol). Results: Resistance was observed only in M. tuberculosis isolates while all isolates of M. bovis were fully susceptible to the four drugs. Thus, the overall resistance of M. tubeculosis isolates to any of the four drugs was 51.7%. As such, any type of drug resistance was most frequent to streptomycin (41.3%) followed by isoniazid (20.6%) while it was minimal to rifampicin (6.8%) and ethambutol (3.4%). Multidrug resistant TB (MDR-TB) was not detected in the study. Conclusion: This preliminary study showed high level of resistance in M. tuberculosis isolates warranting appropriate use of anti-TB drugs in those sites from where the isolates were obtained.