title: In vitro activity of ceftolozane/tazobactam against clinical isolates of Pseudomonas aeruginosa and Enterobacteriaceae recovered in Spanish medical centres: Results of the CENIT study.
abstract: Ceftolozane/tazobactam is a novel antimicrobial agent with activity against Pseudomonas aeruginosa, including drug-resistant strains, and other Gram-negative pathogens, including most extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae. The CENIT study evaluated the in vitro activity of ceftolozane/tazobactam and comparators against clinical isolates of P. aeruginosa (n=500) and Enterobacteriaceae (n=500) collected from patients with complicated intra-abdominal, complicated urinary tract, lower respiratory tract or bloodstream infections in 10 medical centres in Spain (January-September 2013). Antimicrobial susceptibility was determined by the ISO broth microdilution method using commercial dry-form panels and results were interpreted per EUCAST and CLSI guidelines and for ceftolozane/tazobactam with FDA criteria. Ceftolozane/tazobactam and ceftolozane alone were the most potent (MIC(50/90), 0.5/4 mg/L) agents tested against all P. aeruginosa isolates. This advantage was maintained regardless of resistance phenotype, even against isolates resistant to multiple antibiotics. Ceftolozane/tazobactam demonstrated excellent overall activity (MIC50/90, 0.25/0.5 mg/L) against all 250 Escherichia coli isolates, including isolates displaying a wild-type (MIC(90), 0.25/0.25 mg/L) or ESBL (MIC(50/90), 0.5/1mg/L) phenotype, and good activity against isolates displaying an AmpC-like phenotype (MIC range 0.25-4 mg/L). Ceftolozane/tazobactam demonstrated good overall activity (MIC(50/90), 0.25/4 mg/L) against all 104 Klebsiella spp. isolates, although activity was lower against those with an ESBL phenotype (MIC(50/90), 4/16 mg/L), and was inactive against the carbapenemase-producing isolates (MIC≥64 mg/L). Ceftolozane/tazobactam demonstrated excellent in vitro activity against most of the P. aeruginosa and Enterobacteriaceae clinical isolates obtained from medical centres in Spain, supporting the potential value of ceftolozane/tazobactam in treating infections due to these pathogens.
authors: Servicio de Microbiología, Hospital Universitario Ramón y Cajal and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain; Red Española de Investigación en Patología Infecciosa (REIPI), Instituto de Salud Carlos III, Madrid, Spain.
authors: Marta
authors: M
authors: Tato
authors: Servicio de Microbiología, Hospital Universitario Ramón y Cajal and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain; Red Española de Investigación en Patología Infecciosa (REIPI), Instituto de Salud Carlos III, Madrid, Spain.
authors: María
authors: M
authors: García-Castillo
authors: Servicio de Microbiología, Hospital Universitario Ramón y Cajal and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain; CIBER en Epidemiología y Salud Pública (CIBERESP), Instituto de Salud Carlos III, Madrid, Spain.
authors: Ana Moreno
authors: AM
authors: Bofarull
authors: Servicio de Microbiología, Hospital Universitario Ramón y Cajal and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain; Red Española de Investigación en Patología Infecciosa (REIPI), Instituto de Salud Carlos III, Madrid, Spain. Electronic address: rafael.canton@salud.madrid.org.
authors: Rafael
authors: R
authors: Cantón
mesh_terms: D000046:Academic Medical Centers; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002511:Cephalosporins / Q000494:pharmacology*; D004755:Enterobacteriaceae / Q000187:drug effects* / Q000302:isolation & purification; D004756:Enterobacteriaceae Infections / Q000382:microbiology*; D006801:Humans; D008826:Microbial Sensitivity Tests; D010397:Penicillanic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D011446:Prospective Studies; D011552:Pseudomonas Infections / Q000382:microbiology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000302:isolation & purification; D013030:Spain; D000078142:Tazobactam
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins; C000594038:ceftolozane, tazobactam drug combination; D010397:Penicillanic Acid; D000078142:Tazobactam
keywords: Antimicrobial resistance; Ceftolozane/tazobactam; Gram-negative; Surveillance