%0 Journal Article
%A Delgado-Valverde, Mercedes
%A Valiente-Mendez, Adoracion
%A Torres, Eva
%A Almirante, Benito
%A Gomez-Zorrilla, Silvia
%A Borrell, Nuria
%A Aller-Garcia, Ana Isabel
%A Gurgui, Mercedes
%A Almela, Manel
%A Sanz, Mercedes
%A Bou, German
%A Martinez-Martinez, Luis
%A Canton, Rafael
%A Antonio Lepe, Jose
%A Causse, Manuel
%A Gutierrez-Gutierrez, Belen
%A Pascual, Alvaro
%A Rodriguez-Baño, Jesus
%T MIC of amoxicillin/clavulanate according to CLSI and EUCAST: discrepancies and clinical impact in patients with bloodstream infections due to Enterobacteriaceae.
%D 2016
%U http://hdl.handle.net/10668/10780
%X To compare results of amoxicillin/clavulanate susceptibility testing using CLSI and EUCAST methodologies and to evaluate their impact on outcome in patients with bacteraemia caused by Enterobacteriaceae. A prospective observational cohort study was conducted in 13 Spanish hospitals. Patients with bacteraemia due to Enterobacteriaceae who received empirical intravenous amoxicillin/clavulanate treatment for at least 48 h were included. MICs were determined following CLSI and EUCAST recommendations. Outcome variables were: failure at the end of treatment with amoxicillin/clavulanate (FEAMC); failure at day 21; and 30 day mortality. Classification and regression tree (CART) analysis and logistic regression were performed. Overall, 264 episodes were included; the urinary tract was the most common source (64.7%) and Escherichia coli the most frequent pathogen (76.5%). Fifty-two isolates (19.7%) showed resistance according to CLSI and 141 (53.4%) according to EUCAST. The kappa index for the concordance between the results of both committees was only 0.24. EUCAST-derived, but not CLSI-derived, MICs were associated with failure when considered as continuous variables. CART analysis suggested a 'resistance' breakpoint of > 8/4 mg/L for CLSI-derived MICs; it predicted FEAMC in adjusted analysis (OR = 1.96; 95% CI: 0.98-3.90). Isolates with EUCAST-derived MICs >16/2 mg/L independently predicted FEAMC (OR = 2.10; 95% CI: 1.05-4.21) and failure at day 21 (OR= 3.01; 95% CI: 0.93-9.67). MICs >32/2 mg/L were only predictive of failure among patients with bacteraemia from urinary or biliary tract sources. CLSI and EUCAST methodologies showed low agreement for determining the MIC of amoxicillin/clavulanate. EUCAST-derived MICs seemed more predictive of failure than CLSI-derived ones. EUCAST-derived MICs >16/2 mg/L were independently associated with therapeutic failure.
%K Área de Gestión Sanitaria Sur de Sevilla
%K Amoxicillin-potassium clavulanate combination
%K Anti-bacterial agents
%K Bacteremia
%K Enterobacteriaceae
%~