Delgado-Valverde, MercedesTorres, EvaValiente-Mendez, AdoracionAlmirante, BenitoGomez-Zorrilla, SilviaBorrell, NuriaCorzo, Juan EGurgui, MercedesAlmela, ManuelGarcia-Alvarez, LaraFontecoba-Sanchez, Maria CruzMartinez-Martinez, LuisCanton, RafaelPraena, JuliaCausse, ManuelGutierrez-Gutierrez, BelenRoberts, Jason AFarkas, AndrasPascual, AlvaroRodriguez-Baño, Jesus2023-01-252023-01-252015-11-03Delgado-Valverde M, Torres E, Valiente-Mendez A, Almirante B, Gómez-Zorrilla S, Borrell N, et al. Impact of the MIC of piperacillin/tazobactam on the outcome for patients with bacteraemia due to Enterobacteriaceae: the Bacteraemia-MIC project. J Antimicrob Chemother. 2016 Feb;71(2):521-30.http://hdl.handle.net/10668/9615Our objective was to evaluate the impact of low versus borderline MIC of piperacillin/tazobactam on the clinical outcomes of patients with bacteraemia caused by Enterobacteriaceae who were treated with that antimicrobial. A prospective observational multicentre cohort study was conducted in 13 Spanish university hospitals. Patients >17 years old with bacteraemia due to Enterobacteriaceae who received empirical piperacillin/tazobactam treatment for at least 48 h were included. Outcome variables were clinical response at day 21, clinical response at end of treatment with piperacillin/tazobactam and all-cause 30 day mortality. Univariate and multivariate logistic regression analyses were performed. Overall, 275 patients were included in the analysis; 248 (90.2%) in the low MIC group (≤ 4 mg/L) and 27 (9.8%) in the borderline MIC group (8-16 mg/L). The biliary tract was the most common source of infection (48.4%) and Escherichia coli was the most frequent pathogen (63.3%). Crude 30 day mortality rates were 10.5% and 11.1% for the low MIC group and the borderline MIC group, respectively (relative risk = 1.06, 95% CI = 0.34-3.27, P = 1). Multivariate analysis of failure at day 21 and at end of treatment with piperacillin/tazobactam and 30 day mortality showed no trend towards increased clinical failure or mortality with borderline MICs (OR = 0.96, 95% CI = 0.18-4.88, P = 0.96; OR = 0.47, 95% CI = 0.10-2.26, P = 0.35; OR = 1.48, 95% CI = 0.33-6.68, P = 0.6). We did not find that higher piperacillin/tazobactam MIC within the susceptible or intermediate susceptibility range had a significant influence on the outcome for patients with bacteraemia due to Enterobacteriaceae.enEnterobacteriaceae InfectionsBacteremiaMicrobial Sensitivity TestsPiperacillin, Tazobactam Drug CombinationSurvival AnalysisAdolescentAdultAgedAged, 80 and overEnterobacteriaceaeFemaleHospitals, UniversityHumansMaleMiddle AgedPenicillanic AcidPiperacillinProspective StudiesSpainTreatment OutcomeYoung Adultresearch article26538507Restricted AccessInfeccionesEscherichia coliSistema biliarEnterobacteriaceaePiperacilina10.1093/jac/dkv3621460-2091https://academic.oup.com/jac/article-pdf/71/2/521/17429950/dkv362.pdf