García-Fernández, SergioGarcía-Castillo, MaríaBou, GermánGarcía Calvo-Montes, JorgeCercenado, EmiliaDelgado-Valverde, MercedesPitart, CristinaMulet, XavierTormo, NuriaLópez-Mendoza, DiegoDíaz-Regañón, JazmínCantón, Rafael2026-03-182026-03-182019-02-12García-Fernández S, García-Castillo M, Bou G, Calvo J, Cercenado E, Delgado M, Pitart C, Mulet X, Tormo N, Mendoza DL, Díaz-Regañón J, Cantón R; SUPERIOR Study Group. Activity of ceftolozane/tazobactam against Pseudomonas aeruginosa and Enterobacterales isolates recovered from intensive care unit patients in Spain: the SUPERIOR multicentre study. Int J Antimicrob Agents. 2019 May;53(5):682-688.1872-7913https://hdl.handle.net/2183/47746Multicenter study[Abstract] Patients in intensive care units (ICUs) present a high risk of developing an infection caused by multidrug-resistant bacteria. Consequently, new antimicrobials and combinations are required. In this study, the activity of ceftolozane/tazobactam (C/T) was evaluated against Enterobacterales (n = 400) and Pseudomonas aeruginosa (n = 80) clinical isolates collected from patients in Spanish ICUs with complicated urinary tract infections (cUTI) and complicated intra-abdominal infections (cIAI). Overall susceptibility to C/T in P. aeruginosa isolates by infection type was 95.7% in cUTI (MIC50/90, 1/4 mg/L) and 85.3% in cIAI (MIC50/90, 1/64 mg/L). Activity against P. aeruginosa was maintained regardless of its resistance pattern, confirming that C/T is one of the best antipseudomonal agents along with colistin and amikacin. Susceptibility to C/T in Enterobacterales by infection type was 79.5/81.9% and 89.3/92.3% (EUCAST/CLSI) in cIAI and cUTI isolates, respectively. Activity was excellent against wild-type organisms, with 100% susceptible and inhibited at MIC ≤1 mg/L. Nevertheless, C/T susceptibility decreased against extended-spectrum β-lactamase (ESBL)-producing isolates: Escherichia coli (80.4/84.8% susceptible by EUCAST/CLSI) and Klebsiella pneumoniae (59.1/77.3% susceptible by EUCAST/CLSI). No activity of C/T was observed in carbapenemase-producing isolates. The in vitro activity of C/T observed in this surveillance study suggests that this agent can be considered as a therapeutic option for cUTI and cIAI due to Enterobacterales and P. aeruginosa in ICU patients, particularly when carbapenemase-producing isolates are not involved.engAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/Ceftolozane/tazobactamIntensive care unitIntra-abdominal infectionSpainUrinary tract infectionjournal articleopen access10.1016/J.IJANTIMICAG.2019.02.004