Fig. 2. Detection of extended-spectrum β-lactamase (ESBL) with an E-test. Ceftazidime (CAZ) MIC against Escherichia coli isolate in A is >32 µg/mL in the absence of clavulanate and 0.125 µg/mL in the presence of clavulanate. As the ratio of CAZ with and without clavulanate is ≥8, the isolates were phenotypically determined as ESBL producers.
