Epidemiological study of infections caused by extended-spectrum b-lactamase producing Escherichia coli and Klebsiella spp. in a tertiary care hospital in Badajoz, Spain (2003–2005)

Abstract number: 1734_79

Garduño E., Galán-Ladero M.A., Muñoz-Lozano M.T., Sánchez-González M., Blanco-Palenciano J.

Objectives: The aim of this study is to determine the prevalence and antimicrobial resistance pattern of extended-spectrum b-lactamase (ESBL) Escherichia coli, Klebsiella pneumoniae and Klebsiella oxytoca producing isolates over a 3-year period at our institution.

Methods: A retrospective study was performed from January 2003 to December 2005. Identification and antimicrobial susceptibilities were determined using the WalkAway system (Dade–Behring), and ESBL-producing bacteria were confirmed by E-test method. Resistance rates are described as percentage and analysed using Chi2-test. Statistical significance has been considered when p value was <0.05.

Results: Out of the 4,137 isolates studied 227 (5.48%) were ESBLs. 13.21% were isolated during year 2003, 14.53% during 2004 and 72.24% during 2005. The distribution of the ESBL isolates was: 122 (53.74%) E. coli, 103 (45.37%) K. pneumoniae and 2 (0.88%) K. oxytoca. Species distribution by year was: 2003, 25 E. coli and 5 K. pneumoniae; 2004, 23 E. coli, 9 K. pneumoniae and 1 K. oxytoca and 2005, 74 E. coli, 89 K. pneumoniae and 1 K. oxytoca.

Overall, the infection was intrahospitalary in 85.91% of the cases, and most of them in medical areas (38.03%), followed by surgical areas (18.30%) and the ICUs (29.58%). E. coli was more frequently isolated from outpatients (19.82%), whereas K. pneumoniae was was more frequent in patients from ICUs (55.91%). The majority of E. coli was obtained from urine (68.1%), whereas K. pneumoniae from respiratory (39.8%) and invasive (24.7%) samples.

Sensitivity of ESBL-E. coli compared to non-ESBL E. coli was as follows: trimethoprim-sulfamethoxazole (45 and 61%; p < 0.05), fosfomycin (97 and 97%), gentamycin (87 and 92%; p > 0.05) and ciprofloxacin (40 and 69%; p < 0.05). ESBL-K. pneumoniae vs. non-ESBL K. pneumoniae was: trimethoprim-sulfamethoxazole (80 and 81%; p > 0.05), fosfomycin (92 and 87%; p > 0.05), gentamycin (100 and 94%; p >  0.05) and ciprofloxacin (80 and 86%; p >  0.05).

Conclusions: ESBLs have dramatically increased in our hospital over the last three years. In 2005, the more prevalent species was K. pneumoniae isolated from respiratory samples of patients in ICU, suggesting clonal origin (data under further investigation). ESBL-E. coli isolates showed higher and statistically significant resistance to trimethoprim-sulfamethoxazole and ciprofloxacin than non-ESBL E. coli.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
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