title: Antimicrobial activity of ceftazidime-avibactam and comparator agents when tested against bacterial isolates causing infection in cancer patients (2013-2014).
abstract: We evaluated the antimicrobial susceptibility of 623 Gram-negative organisms causing infection in patients with cancer in 52 United States hospitals (2013-2014) as part of the International Network for Optimal Resistance Monitoring (INFORM) program. Isolates were tested for susceptibility by broth microdilution method. β-lactamase encoding genes were evaluated for all Escherichia coli and Klebsiella spp. with an extended-spectrum β-lactamase (ESBL) phenotype by microarray-based assay. ESBL-phenotype was observed among 17.3 and 9.9% of E. coli and Klebsiella pneumoniae, respectively; and 25.0% of Enterobacter cloacae were ceftazidime-non-susceptible. All Enterobacteriaceae (n=486) were susceptible to ceftazidime-avibactam (MIC50/90, 0.12/0.25μg/mL) with the highest MIC value at 1μg/mL. Meropenem was active against Enterobacteriaceae overall (MIC50/90, ≤0.06/≤0.06μg/mL; 99.6% susceptible); but showed more limited activity against Klebsiella spp. with an ESBL-phenotype (84.6% susceptible) and multidrug-resistant Enterobacteriaceae (93.3% susceptible). The most active agents tested against Pseudomonas aeruginosa were colistin (100.0% susceptible), amikacin (97.7% susceptible) and ceftazidime-avibactam (96.6% susceptible).
authors.affiliation: JMI Laboratories, North Liberty, IA, USA. Electronic address: helio-sader@jmilabs.com.
authors.forename: Helio S
authors.initials: HS
authors.lastname: Sader
authors.affiliation: JMI Laboratories, North Liberty, IA, USA.
authors.forename: Mariana
authors.initials: M
authors.lastname: Castanheira
authors.affiliation: JMI Laboratories, North Liberty, IA, USA.
authors.forename: Ronald N
authors.initials: RN
authors.lastname: Jones
authors.affiliation: JMI Laboratories, North Liberty, IA, USA.
authors.forename: Robert K
authors.initials: RK
authors.lastname: Flamm
mesh_terms: D000583:Amikacin / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D053961:Azabicyclo Compounds / Q000494:pharmacology*; D002442:Ceftazidime / Q000494:pharmacology*; D003091:Colistin / Q000494:pharmacology; D004338:Drug Combinations; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D016972:Enterobacter cloacae / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D000077731:Meropenem; D008826:Microbial Sensitivity Tests; D009369:Neoplasms / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D013845:Thienamycins / Q000494:pharmacology; D001618:beta-Lactamases / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D053961:Azabicyclo Compounds; D004338:Drug Combinations; D013845:Thienamycins; C000595613:avibactam, ceftazidime drug combination; D000583:Amikacin; D002442:Ceftazidime; D001618:beta-Lactamases; D000077731:Meropenem; D003091:Colistin
keywords: Beta-lactamase; Cancer; Ceftazidime-avibactam; ESBL; Enterobacteriaceae; Pseudomonas aeruginosa