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Community-onset urinary tract infections caused by ESBL-producing Enterobacteriaceae

Abstract number: P671

Zarkotou O., Giannouli A., Kristo I., Altouvas G., Mamali V., Drimis S., Chrysos G., Voutsinas D., Pournaras S., Digalaki K.

Objectives: ESBL-producing Enterobacteriaceae (ESBLE), especially E. coli, are increasingly identified in community patients mainly with urinary tract infections (UTI). We defined the prevalence of community-onset versus hospital-acquired UTI caused by ESBLE. The clinical data of patients with community onset UTI caused by ESBLE were reviewed.

Methods: A total of 1169 single-patient isolates, recovered from urine cultures of 776 hospitalised patients and 393 outpatients during 2008, were studied. The bacterial species studied were E. coli, K. pneumoniae and P. mirabilis. The identification, MIC determination and screening for ESBLs were performed by the Vitek 2 compact automated system. CLSI approved confirmatory test (combined disk test) was also applied. Clinical isolates co-expressing carbapenemase phenotypes were excluded. All community strains were tested by PCR. The demographic and clinical characteristics of patients were evaluated using medical records.

Results: 83 patients (7.1%) harboured uropathogenic ESBLE. Species distribution was: E. coli 66, 7.2%; K. pneumoniae 14, 11.7%; P. mirabilis 3, 2.3%. Hospital-acquired infections were considered in 24 patients. Healthcare-associated infections were identified in 13 patients (outpatients under haemodialysis or chemotherapy, surgery, prior hospitalisation the past one month). The criteria for community-onset infection were met in 46 patients (55.4%). Female gender was prevalent (33/46). Mean age was 74.9 y (range 27–91 y). Regarding E. coli isolates 36/66 (54.5%) were characterised as community-acquired and resistant rates to quinolones and cotrimoxazole were 79% and 67% respectively, whereas all ESBL-producing P. mirabilis isolates were hospital-acquired. Predominance of community-onset infections was noted for K. pneumoniae (10/14). The rate of ESBLE among patients with community-onset UTI was 7.4% (46/624): E. coli 7% (36/510) and K. pneumoniae 18.5% (10/54). The proportion of ESBLE among hospital and healthcare-associated UTI was 7.4% (37/499). PCR identified 33/36 community E. coli isolates as carrying blaCTX-M gene.

Conclusions: The rate of uropathogens expressing ESBL was similar in community and hospital-acquired strains. This indicates a change in the epidemiology of ESBLE, with a rather high proportion of community isolates to express ESBL, especially CTX-M. It is suggested that empirical administration of beta-lactams for community UTIs should be done with caution in high risk patients.

Session Details

Date: 16/05/2009
Time: 00:00-00:00
Session name: 19th European Congress of Clinical Microbiology and Infectious Diseases
Subject:
Location: Helsinki, Finland, 16 - 19 May 2009
Presentation type:
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