Utilization of extended-spectrum beta-lactamase (ESBL) detection systems in microbiology laboratories: survey of Connecticut hospitals from 1998-2002.

There has been recent concern raised over the detection, prevalence, and clinical implications of infection with Escherichia coli and Klebsiella spp. which produce extended-spectrum beta-lactamases (ESBLs). These enzymes hydrolyze beta-lactams including the cephalosporins (i.e., ceftazidime, ceftriaxone, cefotaxime), thus frequently leading to treatment failures. Standard in vitro testing may report these isolates as susceptible when in fact they are resistant in vivo. As a result of this phenomenon, additional testing for suspected isolates is recommended nationally. We surveyed 28 Connecticut hospitals from 1998-2002 to determine if these institutions utilized screening and confirmation methods for suspected isolates. The number of hospitals which have implemented ESBL detection systems doubled from 11 to 22 over the study period. Currently, 15 of the 22 laboratories conduct both screening and confirmatory testing. This expanded testing will be of great assistance to clinicians in optimizing the clinical care of patients with Gramnegative infections.