FIG. 1.

Etest results for a clinical isolate of M. tuberculosis after 10 days of incubation. Resistance to RIF (MIC, >32 μg/ml) is evidenced by the presence of growth along the strip (top left); susceptibility to INH (MIC, <0.016 μg/ml) is evidenced by a lack of growth in the whole plate (bottom left); and an inhibition ellipse is observed in the STR plate (top right), in which a MIC of 0.25 μg/ml (susceptible) is read. No Etest strip was placed on the control plate (bottom right). The EMB plate is not shown here.