In vitro activity of doripenem relative to meropenem and imipenem against Enterobacteriaceae and P. aeruginosa isolates from Europe (2006–2007)

Abstract number: P1168

Torres M., Draghi D., Brown N., Thornsberry C., Sahm D., Pillar C.

Objective: Carbapenems are widely used to treat infections involving resistant Gram-negative pathogens due to their potent activity against extended b-lactamase producing enteric bacilli and P. aeruginosa (PA). Doripenem (DOR), a 1-beta-methyl carbapenem, is approved to treat complicated urinary tract infections (cUTI) and intra-abdominal infections (IAI) in the US, and is currently undergoing regulatory review for the treatment of cUTI and IAI in Europe (EU), and nosocomial pneumonia both in the US and EU. This study examined the in vitro activity of DOR relative to other currently available carbapenems against Gram-negative pathogens recently isolated from EU.

Methods: During 2006 and 2007, Enterobacteriaceae (EN) and PA isolates from patient specimens were collected from 28 laboratories in 11 EU countries. All isolates were centrally tested by broth microdilution against DOR, imipenem (IPM), and meropenem (MER) at Eurofins Medinet, Inc. (CLSI; M7–A7). Data were interpreted according to CLSI M100-S17 for IPM and MER. For DOR, there are no CLSI approved breakpoints.

Results: By MIC50/90, DOR and MER were similar in activity against the tested isolates and were superior to IPM, regardless of CAZ susceptibility. The MICs of DOR and MER were lower than IPM against the EN and PA tested.

Conclusion: EN from EU were highly susceptible (>99%) to the carbapenems tested, while susceptibility of PA ranged from 76% for IPM to 85% for MER, respectively. MICs of IPM were higher against both PA and EN than MICs of either DOR or MER, which were of similar activity by MIC50/90. The increasing prevalence of carbapenemases among EN and the high-level resistance commonly encountered among PA highlights the importance of continued surveillance of carbapenem activity against these organisms.

Session Details

Date: 19/04/2008
Time: 00:00-00:00
Session name: 18th European Congress of Clinical Microbiology and Infectious Diseases
Location: Barcelona, Spain
Presentation type:
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