title: Ceftolozane/tazobactam activity tested against Gram-negative bacterial isolates from hospitalised patients with pneumonia in US and European medical centres (2012).
abstract: During 2012, a total of 2968 isolates were consecutively collected from 59 medical centres in the USA and 15 European countries from hospitalised patients with pneumonia. Ceftolozane/tazobactam (tazobactam at a fixed concentration of 4mg/L) and comparator agents were tested by reference methods, and MIC endpoints were interpreted by CLSI (2013) and EUCAST (2013) breakpoint criteria. Pseudomonas aeruginosa was the most common isolated pathogen (1019 strains; 34.3%), and ceftolozane/tazobactam was the most active β-lactam tested against P. aeruginosa (MIC50/90, 0.5/4 mg/L; 94.1% inhibited at ≤ 8 mg/L). P. aeruginosa exhibited moderate susceptibility to meropenem (MIC50/90, 0.5/>8 mg/L; 73.7% susceptible), ceftazidime (MIC50/90, 2/>32 mg/L; 73.6% susceptible), cefepime (MIC50/90, 4/>16 mg/L; 76.5% susceptible), piperacillin/tazobactam (MIC50/90, 8/>64 mg/L; 69.5% susceptible), levofloxacin [MIC50/90, 0.5/>4 mg/L; 69.9/61.0% susceptible (CLSI/EUCAST criteria)] and gentamicin (MIC50/90, 2/>8 mg/L; 80.7% susceptible). Ceftolozane/tazobactam exhibited activity against many ceftazidime-non-susceptible, meropenem-non-susceptible and piperacillin/tazobactam-non-susceptible, multidrug-resistant (MDR) and extensively drug-resistant (XDR) P. aeruginosa isolates. Ceftolozane/tazobactam was active (MIC50/90, 0.25/4mg/L; 94.6% inhibited at ≤ 8 mg/L) against 1530 Enterobacteriaceae, including activity against many MDR and XDR strains. MDR and XDR prevalence varied widely between countries both for P. aeruginosa (24.1% MDR and 17.1% XDR overall) and Enterobacteriaceae (15.4% MDR and 2.7% XDR overall). All β-lactams had limited activity against Acinetobacter spp. and Stenotrophomonas maltophilia. Ceftolozane/tazobactam demonstrated greater in vitro activity than currently available cephalosporins, carbapenems and piperacillin/tazobactam when tested against P. aeruginosa. In addition, ceftolozane/tazobactam demonstrated greater activity than contemporary cephalosporins and piperacillin/tazobactam when tested against most Enterobacteriaceae.
authors.affiliation: JMI Laboratories, 345 Beaver Kreek Center, Suite A, North Liberty, IA 52317, USA. Electronic address: david-farrell@jmilabs.com.
authors.forename: David J
authors.initials: DJ
authors.lastname: Farrell
authors.affiliation: JMI Laboratories, 345 Beaver Kreek Center, Suite A, North Liberty, IA 52317, USA.
authors.forename: Helio S
authors.initials: HS
authors.lastname: Sader
authors.affiliation: JMI Laboratories, 345 Beaver Kreek Center, Suite A, North Liberty, IA 52317, USA.
authors.forename: Robert K
authors.initials: RK
authors.lastname: Flamm
authors.affiliation: JMI Laboratories, 345 Beaver Kreek Center, Suite A, North Liberty, IA 52317, USA.
authors.forename: Ronald N
authors.initials: RN
authors.lastname: Jones
mesh_terms: D000046:Academic Medical Centers; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002511:Cephalosporins / Q000494:pharmacology*; D003428:Cross Infection / Q000382:microbiology*; D005060:Europe; D006090:Gram-Negative Bacteria / Q000187:drug effects* / Q000302:isolation & purification; D016905:Gram-Negative Bacterial Infections / Q000382:microbiology*; D006801:Humans; D008826:Microbial Sensitivity Tests; D010397:Penicillanic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D018410:Pneumonia, Bacterial / Q000382:microbiology*; D000078142:Tazobactam; D014481:United States
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins; C000594038:ceftolozane, tazobactam drug combination; D010397:Penicillanic Acid; D000078142:Tazobactam
keywords: Ceftolozane/tazobactam; Nosocomial; Pneumonia; Surveillance