Comparative study of 3 tests for susceptibility of Mycobacterium tuberculosis to first-line antituberculous drugs
Delás, M.A.; Martínez, C.; Yagüe, C.; Rodríguez, T.; Rodríguez, T.; Segovia, M.
Revista Espanola de Quimioterapia Publicacion Oficial de la Sociedad Espanola de Quimioterapia 14(1): 40-46
2001
ISSN/ISBN: 0214-3429 PMID: 11376348 Document Number: 527094
Treatment of tuberculosis requires a multidrug regimen for a prolonged period of time (6-12 months), which leads to a high level of noncompliance with therapy. This lack of compliance has led to an increase in drug-resistant strains of Mycobacterium tuberculosis. Rapid drug susceptibility tests are needed to assess effective chemotherapy regimens. In the present study, the reliability of ESP Myco System II(R) and E-test(R) for determining the susceptibility of 82 clinical isolates of M. tuberculosis to rifampin, isoniazid, streptomycin and ethambutol was evaluated by comparing results to those of the multiple proportion method as a reference. ESP Myco System II(R) is a nonradioactive, totally automated, continuously monitored system designed to detect grown mycobacteria. E-test(R) is a well-described method of susceptibility testing which provides data on minimal inhibitory concentration. The susceptibility results of both methods were available within 9 days, while those of the proportion method required 28 days. Levels of agreement between ESP Myco System II(R) and the proportion method for the clinical isolates analyzed were 100% for rifampin, isoniazid and ethambutol. Only one discrepancy was found for streptomycin. For the E-test(R), the results were less favorable. ESP Myco System II(R) was shown to be a rapid and reliable method for testing susceptibility of M. tuberculosis isolates. Nevertheless, E-test(R) provided low specificity for streptomycin and ethambutol. Further studies to test the reliability of the E-test(R) are necessary.