Epidemiology and risk factors for infections due to AmpC ß-lactamase-producing Escherichia coli.
J Antimicrob Chemother
; 70(3): 899-904, 2015 Mar.
Article
em En
| MEDLINE
| ID: mdl-25468902
ABSTRACT
OBJECTIVES:
To describe the prevalence and risk factors for infection due to AmpC ß-lactamase-producing Escherichia coli (AmpC-EC).METHODS:
For the prevalence study, all clinical isolates of E. coli with reduced susceptibility to third-generation cephalosporins were prospectively included from June 2010 to November 2011. For risk factor analysis, a case-control study was conducted. Cases were patients with an infection due to AmpC-EC. Controls were patients infected with cephalosporin-susceptible E. coli, matched 1ââ2. Detection of blaAmpC genes was done with a multiplex AmpC-PCR, and hyperproduction of E. coli chromosomal blaAmpC by quantitative RT-PCR. Alteration of the blaAmpC promoter was studied by PCR and sequencing.RESULTS:
We identified 243 (1.1%) AmpC-EC strains out of 21â563 clinical isolates. Three cases with strains carrying ESBLs, 18 strains that were considered due to colonization and 8 cases lost to clinical follow-up were excluded. Finally, 214 cases were included in the analysis. Ninety-one cases (42.5%) and 269 (62.8%) controls were strictly community acquired (Pâ<â0.001). Thirty-five (16.3%) cases and 186 controls (43.5%) did not have any identifiable risk factor (Pâ<â0.001). Among cases, 158 (73.8%) were found to harbour an acquired AmpC (73.4% CMY-2). Previous use of fluoroquinolones [OR 2.6 (95% CI 1.12-3.36); Pâ=â0.008] was independently associated with AmpC-EC in the multivariate analysis.CONCLUSIONS:
Prevalence of AmpC in E. coli remains low in our area. Plasmid acquisition (CMY type) represents the main mechanism of AmpC production. A high proportion of community-acquired isolates and patients with no identifiable risk factors were found. Previous use of fluoroquinolones was identified as a risk factor.Palavras-chave
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Proteínas de Bactérias
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Beta-Lactamases
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Escherichia coli
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Infecções por Escherichia coli
Tipo de estudo:
Etiology_studies
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Observational_studies
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Prevalence_studies
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Prognostic_studies
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Risk_factors_studies
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Screening_studies
Limite:
Adult
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Aged
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Aged80
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Ano de publicação:
2015
Tipo de documento:
Article