High Prevalence of KPC-2-Type Carbapenemase Coupled with CTX-M-Type Extended-Spectrum β-Lactamases in Carbapenem-Resistant Klebsiella pneumoniae in a Teaching Hospital in China

High Prevalence of KPC-2-Type Carbapenemase Coupled with CTX-M-TypeExtended-Spectrum ␤-Lactamases in Carbapenem-Resistant Klebsiella pneumoniae in a Teaching Hospital in China ᰔ Carbapenems such as imipenem and meropenem are the first-line agents for the treatment of serious nosocomial infections caused by multidrug-resistant Enterobacteriaceae clinical isolates (2).However, the phenomenon of carbapenem resistance is emerging among a wide variety of these species (11).Carbapenemases have been widespread in recent years and predominantly contribute to carbapenem resistance among Enterobacteriaceae, especially Klebsiella pneumoniae and Citrobacter freundi (8).For screening of the carbapenem-resistant Enterobacteriaceae clinical isolates, we conducted a surveillance study of carbapenem-resistant Enterobacteriaceae isolates in order to investigate the frequency and prevalence of K. pneumoniae carbapenemase (KPC)-type genes in Huashan Hospital (Fudan University, Shanghai, China), a 1,300-bed tertiary care hospital.We hereby report a high prevalence of carbapenem-resistant K. pneumoniae isolates carrying the KPC-2-type carbapenemase gene or KPC-2-type carbapenemase gene coupled with the CTX-M-type extended-spectrum ␤-lactamase (ESBL) gene.From January 2005 to March 2010, 109 nonduplicate Klebsiella pneumoniae isolates with resistance to ertapenem were collected.Antimicrobial susceptibility testing was performed by the agar dilution method, and MICs were interpreted following CLSI (4) or British Society for Antimicrobial Chemotherapy (BSAC) criteria (1).The presence of genes encoding