title: Comparison of recalcitrance to ciprofloxacin and levofloxacin exhibited by Pseudomonas aeruginosa bofilms displaying rapid-transport characteristics.
abstract: Attenuated total reflection Fourier transform infrared spectroscopy was used to measure transport of the fluoroquinolones (FQs) ciprofloxacin and levofloxacin into Pseudomonas aeruginosa biofilms. Biofilms were exposed to each FQ at dose levels of 100, 250, and 500 microg/ml for 30 min. A mathematical transport model was used to extract the diffusion coefficient, binding site density, and adsorption and desorption rates for each experiment. Recalcitrance of the biofilms toward each FQ was evaluated by comparison of efficacies with planktonic bacteria. By this criterion, biofilms were found to exhibit more recalcitrance toward levofloxacin than ciprofloxacin under the experimental conditions. These results cannot be explained by the more hindered transport of levofloxacin, implicating the domination of physiological factors.
authors.affiliation: Center for Biofilm Engineering, Montana State University, Bozeman 59717, USA.
authors.forename: J D
authors.initials: JD
authors.lastname: Vrany
authors.forename: P S
authors.initials: PS
authors.lastname: Stewart
authors.forename: P A
authors.initials: PA
authors.lastname: Suci
mesh_terms: D000890:Anti-Infective Agents / Q000493:pharmacokinetics*; D018441:Biofilms / Q000187:drug effects; D001692:Biological Transport; D002939:Ciprofloxacin / Q000493:pharmacokinetics*; D064704:Levofloxacin; D015242:Ofloxacin / Q000493:pharmacokinetics*; D011550:Pseudomonas aeruginosa / Q000378:metabolism* / Q000502:physiology; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000890:Anti-Infective Agents; D002939:Ciprofloxacin; D064704:Levofloxacin; D015242:Ofloxacin