title: In vitro activity of daptomycin in combination with low-dose colistin against a diverse collection of Gram-negative bacterial pathogens.
abstract: The activity of colistin in combination with daptomycin was assessed using 30 Gram-negative type strains and multidrug-resistant isolates with defined mechanisms of resistance. Daptomycin minimum inhibitory concentrations (MICs) were determined with and without sub-inhibitory concentrations of colistin. The activity of daptomycin was not affected with respect to Escherichia coli, Klebsiella pneumoniae or Pseudomonas aeruginosa. For colistin-susceptible Acinetobacter baumannii, sensitisation factors ranged from 8 to 128 (median 32), with the daptomycin MIC being reduced to the Clinical and Laboratory Standards Institute (CLSI) enterococci susceptibility breakpoint of 4 μg/ml for the ATCC 19606 type strain. A combination of daptomycin and colistin may be useful for the treatment of A. baumannii but not infections due to other Gram-negative species.
authors.affiliation: Antimicrobial Research Group, Centre for Immunology and Infectious Disease, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University London, Blizard Building, 4 Newark Street, Whitechapel, London, E1 2AT, UK.
authors.forename: L
authors.initials: L
authors.lastname: Phee
authors.forename: M
authors.initials: M
authors.lastname: Hornsey
authors.forename: D W
authors.initials: DW
authors.lastname: Wareham
mesh_terms: D003091:Colistin / Q000494:pharmacology*; D017576:Daptomycin / Q000494:pharmacology*; D004357:Drug Synergism; D006090:Gram-Negative Bacteria / Q000187:drug effects* / Q000302:isolation & purification; D016905:Gram-Negative Bacterial Infections / Q000382:microbiology; D006801:Humans; D008826:Microbial Sensitivity Tests
chemical_list: D017576:Daptomycin; D003091:Colistin