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Carbapenem-resistant K.pneumoniae: epidemiology and molecular analysis of a 6year period (20042009)

Abstract number: P1277

Moraitou H., Makarona M., Mavrommati A., Galani I., Soufla N., Tsarpali P., Georgousi A., Anthoulaki C., Spyropoulos V., Kanavaki S.

Objectives: Carbapenem resistance in K. pneumoniae (CRKP) strains is emerging worldwide. The aim of this study was to retrospectively analyze the epidemiology and mechanisms of resistance of CRKP, in our Hospital throughout 2004–2009.

Materials and Methods: All CRKP isolates were collected since 2003, when the first resistant strain occurred in our hospital. From January 2004 to June 2009, 209 single patient/ CRKP strains were isolated both from ICU and non-ICU patients. Susceptibility testing was performed by Kirby Bauer, E-test and Vitek2 automated system, according to CLSI guidelines. All strains were further tested for the production of various b-lactamases, both phenotypically (VIM EDTA test, E-test imipenem, Hodge test, boronic acid/imipenem disc test) and by PCR for the detection of blaVIM and blaKPC gene. Rep-PCR was performed to investigate the clonal spread of isolates.

Results: The overall emergence of CRKP strains throughout the study period was 16.4% (187/1140 K. pneumoniae). In 2004, 18 CRKP were isolated out of 199 K. pneumoniae strains (9.0%). The following years (2005–08) the rate was 10.1%, 8.8%, 10.4%, 25.6% respectively, and up to 26.7% in the first semester of 2009. All CRKP isolates throughout 2004 to 2007 harbored the blaVIM gene (100%), while blaKPC emerged up to 23.3% (17/73) in 2008 and 73.7% (14/17) in 2009. Rep-PCR proved the clonal spread of resistant strains. The most of the strains originated from ICU patients (57.7%), although the rate decreased from 88.8% in 2004, to 45.2% in 2008 and 47.0% in the first semester of 2009.

Conclusions: There is an increasing rate of CRKP prevalence in our Hospital since 2004, when the first metallo-b lactamase producers emerged. It is of interest, that in 2004–07, when only blaVIM harbouring strains were detected, the rate of CRKP remained rather stable. When KPCs emerged in 2008, they dominated and were rapidly disseminated in several units, making KPC production the commonest mechanism of carbapenemase resistance in the Hospital the last years. The infection control committee should be alerted in any case and measures should be taken to avoid further dissemination. The microbiology laboratory could contribute to this purpose, by including phenotypic investigation of all multidrug resistant Enterobacteriaceae in routine practice.

Session Details

Date: 10/04/2010
Time: 00:00-00:00
Session name: Abstracts 20th European Congress of Clinical Microbiology and Infectious Diseases
Subject:
Location: Vienna, Austria, 10 - 13 April 2010
Presentation type:
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