Evaluation of Etest for susceptibility testing of multidrug-resistant isolates of Mycobacterium tuberculosis.
To prescribe effective treatment schemes for patients with tuberculosis, more-efficient susceptibility testing techniques for Mycobacterium tuberculosis are needed, especially in regions with multidrug resistance. Etest (AB BIODISK, Solna, Sweden) is a simple technique that provides quantitative drug susceptibility results for M. tuberculosis in 5 to 10 days from a culture grown at low cost. The performance of Etest was compared to that of the reference proportion method, using 95 M. tuberculosis clinical isolates of which 42.1% (40 of 95) were resistant to at least one antibiotic by the reference method. Overall agreement between Etest and the reference method was 98.9% (94 of 95) for detection of multidrug resistance; for resistance to individual drugs, agreement was 97.9% (93 of 95) for rifampin, 96.0% (92 of 95) for ethambutol, 94.7% (90 of 95) for isoniazid, and 85.3% (81 of 95) for streptomycin. This study supports the utility of Etest for timely detection of drug resistance in M. tuberculosis and for use in tuberculosis control programs.
Hazbón
M H
MH
Centro Internacional de Entrenamiento e Investigaciones Médicas (CIDEIM), Cali, Colombia. molecular@cideim.org.co
del Socorro Orozco
M
M
Labrada
L A
LA
Tovar
R
R
Weigle
K A
KA
Wanger
A
A
D004352:Drug Resistance, Microbial; D018432:Drug Resistance, Multiple; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods*; D009169:Mycobacterium tuberculosis / Q000187:drug effects*; D012680:Sensitivity and Specificity