Evaluation of Efficiency of Screening Extended-Spectrum β-Lactamase-Producing Escherichia coli and Klebsiella pneumoniae in Hospitals Where the Bacteria Are Increasingly Prevalent

The disk screening methods for extended-spectrum β-lactamase-producing strains were evaluated. The confirmatory work is reduced significantly in settings such as those in this study, by changing the cefpodoxime breakpoint to ≤20 mm and by not testing cefoxitin-resistant isolates. Cefotaxime and ceftazidime disk screening is reliable, and the laboratory-prepared cefotaxime- and ceftazidime-clavulanic acid disks are stable at −20°C for 12 weeks.