TY - JOUR
T1 - MIC of amoxicillin/clavulanate according to CLSI and EUCAST: Discrepancies and clinical impact in patients with bloodstream infections due to Enterobacteriaceae
AU - Delgado-Valverde, Mercedes
AU - Valiente-Mendez, Adoración
AU - Torres, Eva
AU - Almirante, Benito
AU - Gómez-Zorrilla, Silvia
AU - Borrell, Nuria
AU - Aller-García, Ana Isabel
AU - Gurgui, Mercedes
AU - Almela, Manel
AU - Sanz, Mercedes
AU - Bou, Germán
AU - Martínez-Martínez, Luis
AU - Cantón, Rafael
AU - Lepe, Jose Antonio
AU - Causse, Manuel
AU - Gutiérrez-Gutiérrez, Belén
AU - Pascual, Álvaro
AU - Rodríguez-Baño, Jesús
AU - Cueto, Marina de
AU - Planes-Reig, Ana María
AU - Tubau-Quintano, Fe
AU - Peña, Carmen
AU - de Alegría, Carlos Ruíz
AU - Morosini, M. Isabel
AU - Shan, Adriana
AU - Cisneros, José Miguel
AU - Corzo, J. Enrique
AU - Prim, Núria
AU - Galán, María Elvira
AU - García-Álvarez, Lara
AU - Gracia-Ahufinger, Irene
AU - Guzmán-Puche, Julia
AU - Torre-Cisneros, Julián
PY - 2017/1/1
Y1 - 2017/1/1
N2 - © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. Objectives: 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. Patients and methods: 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 48h 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. Results: Overall, 264 episodes were included; the urinary tract was the most common source (64.7%) and Escherichia coli themost 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 > 8/4mg/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.32/2mg/Lwere only predictive of failure among patientswith bacteraemia from urinary or biliary tract sources. Conclusions: 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.
AB - © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. Objectives: 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. Patients and methods: 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 48h 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. Results: Overall, 264 episodes were included; the urinary tract was the most common source (64.7%) and Escherichia coli themost 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 > 8/4mg/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.32/2mg/Lwere only predictive of failure among patientswith bacteraemia from urinary or biliary tract sources. Conclusions: 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.
U2 - 10.1093/jac/dkw562
DO - 10.1093/jac/dkw562
M3 - Article
VL - 72
SP - 1478
EP - 1487
IS - 5
ER -