Ertapenem, imipenem, meropenem, tigecycline and fosfomycin activity against extended-spectrum b-lactamase producing Enterobacteriaceae in Austria

Abstract number: P1169

Apfalter P., Zasmeta S., Graf A., Makristathis A., Hirschl A.

Objectives: Reported here are current Austrian susceptibility data on imipenem, meropenem, ertapenem, tigecycline and fosfomycin in ESBL-producing enterobacteriaceae.

Methods: ESBL production was detected by CLSI methods and an expanded double disk diffusion synergy test in 401 non-duplicate enterobacteriaceae (collection period June 04 to Dec 06). MICs were determined by means of Etest®. Strains not fully susceptible to one of the carbapenems were checked for the presence of metallo-b-lactamases by Etest® and typed by means of random amplification of polymorphic DNA (RAPD) and enterobacterial repetitive intergenic consensus (ERIC)-PCR.

Results: Strains were isolated from urine (44%), wounds (25%), the respiratory tract (14.5%), blood (4.5%), faeces (9%), and intravasal devices (2%). The table displays susceptibility data for the species E. coli, Klebsiella spp., and Enterobacter spp. No metallo-b-lactamases could be detected in strains with reduced carbapenem susceptibility. In addition, these strains were not clonally related.

Conclusions: Carbapenems were the most active antibiotics and E. coli was the most susceptible species tested. The lowest MICs were found for meropenem. According to CLSI and EUCAST, 3.4% and 10% strains were not fully susceptible to ertapenem, respectively. Thus, its susceptibility cannot reliably be predicted by testing imipenem or meropenem. Fosfomycin and tigecycline can be therapeutic options, but empiric susceptibility cannot be safely assumed and both agents should be tested.

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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