[Evaluation of E-test method in determination of susceptibility of Mycobacterium tuberculosis to four antituberculosis drugs].
The objective of this study is to evaluate the performance of E-test method versus the standard proportion method, by testing susceptibility of Mycobacterium tuberculosis to four antituberculosis drugs: rifampicin, isoniazid, streptomycin, and ethambutol. Thirty strains isolated at Medical Biology Laboratory of Pasteur Institute of Dakar were tested. The strains were identified by morphological, cultural and biochemical characteristics (microscopy, time of growth, type of colonies, catalase, niacin-test). H37RV strain was tested as reference strain. The E-test method was performed on 7H11 agar with OADC, and the standard proportion method was performed on Lowenstein-Jensen agar. With results of these tests, the authors determined the E-test sensitivity and specificity, and the positive and negative predictive values (PPV, NPV). E-test method gave correct results from the eighth day, with stability of the zone of inhibition until the 21st day. The E-test method has 73% of sensibility and 100% of specificity, with 100% of PPV and 78% of NPV for streptomycin. For isoniazid, these results are respectively: 16.6%, 100%, 100% and 82.7%. There was found a good correlation between the two methods.
Djiba
M L
ML
Faculté des Sciences et Techniques, Département de Biologie Animale, UCAD, BP 991, Dakar, Liberté.
Sow
A I
AI
Ndiaye
M
M
Dromigny
J A
JA
D000995:Antitubercular Agents / Q000494:pharmacology*; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods*; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000472:pathogenicity; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014397:Tuberculosis, Pulmonary / Q000188:drug therapy*
D000995:Antitubercular Agents