title: In vitro activity of ceftazidime/avibactam against urinary isolates from patients in a Phase 3 clinical trial programme for the treatment of complicated urinary tract infections.
abstract: To evaluate the in vitro activity of ceftazidime/avibactam relative to comparator agents against Gram-negative isolates from a Phase 3 clinical trial programme for complicated urinary tract infections (RECAPTURE).
  
  
  
  The in vitro activity of ceftazidime/avibactam was evaluated against 840 Gram-negative pathogens isolated at baseline from 1033 randomized patients in two pivotal Phase 3 clinical trials for the treatment of complicated urinary tract infections. The trials were conducted in 160 institutions from 25 countries worldwide. Susceptibility testing was performed by broth microdilution at a central laboratory according to CLSI methodologies.
  
  
  
  Overall, ceftazidime/avibactam showed significant activity against the Enterobacteriaceae and Pseudomonas aeruginosa with MIC 90 values of 0.5 and 8 mg/L, respectively. Against the most common Enterobacteriaceae, MIC 90 values were 0.25 mg/L for Escherichia coli , 1 mg/L for Klebsiella pneumoniae , 0.06 mg/L for Proteus mirabilis and 2 mg/L for Enterobacter cloacae . The ceftazidime/avibactam MIC 90 for 154 ceftazidime-non-susceptible isolates of Enterobacteriaceae was 1 mg/L and the ceftazidime/avibactam MIC 90 for 15 non-susceptible isolates of P. aeruginosa was 64 mg/L. There was a significant reduction in the ceftazidime/avibactam MIC relative to ceftazidime alone for most of the Enterobacteriaceae isolates.
  
  
  
  The ceftazidime/avibactam in vitro activity against these clinical urinary tract isolates demonstrates the potential utility of the drug in complicated urinary tract infections.
authors.affiliation: AstraZeneca Pharmaceuticals, 35 Gatehouse Drive, Waltham, MA 02451, USA.
authors.forename: Gregory G
authors.initials: GG
authors.lastname: Stone
authors.affiliation: AstraZeneca Pharmaceuticals, 35 Gatehouse Drive, Waltham, MA 02451, USA.
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Bradford
authors.affiliation: AstraZeneca, Alderley Park, Macclesfield, Cheshire SK10 4TG, UK.
authors.forename: Katrina
authors.initials: K
authors.lastname: Yates
authors.affiliation: AstraZeneca Global Medicines Development, Alderley Park, Macclesfield, Cheshire SK10 4TG, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: Newell
mesh_terms: D000900:Anti-Bacterial Agents / Q000493:pharmacokinetics / Q000494:pharmacology* / Q000627:therapeutic use; D053961:Azabicyclo Compounds / Q000493:pharmacokinetics / Q000494:pharmacology* / Q000627:therapeutic use; D002442:Ceftazidime / Q000493:pharmacokinetics / Q000494:pharmacology* / Q000627:therapeutic use; D018550:Cephalosporin Resistance; D004338:Drug Combinations; D016972:Enterobacter cloacae / Q000187:drug effects; D004755:Enterobacteriaceae / Q000187:drug effects* / Q000302:isolation & purification; D004926:Escherichia coli / Q000187:drug effects; D016905:Gram-Negative Bacterial Infections / Q000188:drug therapy / Q000382:microbiology*; D006801:Humans; D059413:Intraabdominal Infections / Q000188:drug therapy / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D014552:Urinary Tract Infections / Q000150:complications / Q000188:drug therapy / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents; D053961:Azabicyclo Compounds; D004338:Drug Combinations; C000595613:avibactam, ceftazidime drug combination; D002442:Ceftazidime