Prevalence, Molecular Characterization, And Phenotypic Confirmation of Extended-Spectrum Beta-Lactamases in Escherichia Coli, Klebsiella Pneumoniae, And Klebsiella Oxytoca at the Radboud University Nijmegen Medical Centre in the Netherlands (Report‪)‬

Introduction WORLDWIDE BETA-LACTAM RESISTANCE among Enterobacteriaceae, mediated by extended-spectrum betalactamases (ESBLs), is increasing. Data on ESBLs from The Netherlands are, however, limited to only two older studies, and it is expected that the prevalence of ESBLs is increasing in The Netherlands, despite restrictive antimicrobial policies. (1,23) Moreover, surveillance programs also report trends of rising third-generation cephalosporin resistance in Escherichia coli and Klebsiella pneumoniae. (8,24) The aim of this study was to determine the prevalence of ESBLs and to characterize the ESBL genes in consecutive unselected clinical isolates of E. coli, K. pneumoniae, and Klebsiella oxytoca collected at the University Medical Centre Nijmegen, The Netherlands. In addition, the detection of ESBLs using the Phoenix automated microbiology system (Becton Dickinson, Sparks, MD) as a first screen with confirmation by phenotypic tests was evaluated.