Frequency of extended-spectrum lactamase in Escherichia coli and Klebsiella spp. and Proteus spp. over a five-year period in a university hospital, Spain

Abstract number: R2407

Palacian M., Marne C., Rezusta A., Monforte M., Villuendas C., Martin G., Aísa M., Marco M., Hernandez M., Revillo M.

Objectives: To study the prevalence of extended-spectrum b-lactamase-producing (ESBL) Escherichia coli, Klebsiella spp and Proteus spp strains during the period 2005–2009.

Methods: A retrospective study of ESBL-producing E. coli, Klebsiella spp and Proteus spp strains isolated from clinical samples of hospitalized and outpatients attended in the Hospital Universitario Miguel Servet of Zaragoza (Spain) from 2005 to 2009 was performed.

Isolates were identified and tested for antibiotic susceptibility by microdilution system (MicroScan Walkaway® Siemens). ESBL production was confirmed by the double-disk diffusion method according to CLSI standards.

Results: In our study 27887 E. coli, 4422 K. pneumoniae, 1042 K. oxytoca, 1852 P. mirabilis and 45 P. vulgaris strains were isolated. The prevalence of ESBL-producing Enterobacteriaceae is shown in table 1. ESBL-producing strains were more frequently isolated from urine samples: 92.94% of E. coli, 64.10% of K. pneumoniae, 41.86% of K. oxytoca and 100% of Proteus spp strains.


1During 2009 isolation of EBSL-producing E. coli. been increased.

2E. coli remains the most frequent isolated species with this characteristic.

3The punctual increase in 2006 of ESBL K. oxytoca was due to an outbreak in an intensive care unit.

Session Details

Date: 07/05/2011
Time: 00:00-00:00
Session name: Abstracts of 21st ECCMID / 27th ICC
Location: Milan, Italy, 7 - 10 May 2011
Presentation type:
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