Faropenem Disks for Screening of Klebsiella pneumoniae Carbapenemase-Producing Enterobacteriaceae

Abstract

In the United States and several other countries, Klebsiella pneumoniae carbapenemase (KPC) is by far the most common carbapenemase found in Enterobacteriaceae (4). In this study, we tested the ability of faropenem disks as well as carbapenem disks to predict KPC production using 62 unique KPC-producing Enterobacteriaceae isolates, including K. pneumoniae (n = 31), Escherichia coli (n = 20), and Enterobacter spp. (n = 11). The presence of the KPC gene was confirmed by PCR. Seventy-three isolates producing extended-spectrum or AmpC β-lactamases were used as controls (5, 6). Only one isolate was included from a given patient. The disk diffusion testing was performed with ertapenem, imipenem, meropenem (disks obtained from BD, Sparks, MD), tebipenem, and faropenem (disks obtained from Eiken Chemical Co., Tokyo, Japan) using the standard methodology endorsed by the Clinical and Laboratory Standards Institute. Tebipenem is an oral carbapenem which is approved for clinical use in Japan. All disks contained 10 μg of the agent, except the faropenem disks, which contained 5 μg of the agent.