title: Bacteriostatic versus bactericidal activity of ciprofloxacin in Escherichia coli assessed by flow cytometry using a novel far-red dye.
abstract: As common microbiological methods for the assessment of bacteriostatic or bactericidal activities are very time-consuming, in this work we describe that the use of a novel far-red fluorescent stain, Vybrant DyeCycle Ruby (DCR) for the flow cytometric analysis of fluoroquinolone (ciprofloxacin) bacteriostatic and bactericidal activities in Escherichia coli proved to be specific for bacterial DNA and, after ciprofloxacin exposure, DNA distribution analysis was achieved using a 7.5 μM DCR concentration to stain 5 × 10⁵ ethanol-fixed bacterial cells. The analysis of the bacterial DNA histograms obtained from the ciprofloxacin concentrations tested, enabled the distinction between ciprofloxacin bacteriostatic and bactericidal activities.
authors.affiliation: CICS-UBI-Health Sciences Research Centre, University of Beira Interior, Covilhã, Portugal. fdomingues@ubi.pt
authors.forename: Filomena
authors.initials: F
authors.lastname: Silva
authors.forename: Olga
authors.initials: O
authors.lastname: Lourenço
authors.forename: João A
authors.initials: JA
authors.lastname: Queiroz
authors.forename: Fernanda C
authors.initials: FC
authors.lastname: Domingues
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002939:Ciprofloxacin / Q000494:pharmacology*; D004269:DNA, Bacterial / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004926:Escherichia coli / Q000187:drug effects*; D005434:Flow Cytometry / Q000379:methods; D005456:Fluorescent Dyes / Q000737:chemistry*; D008826:Microbial Sensitivity Tests / Q000379:methods
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D005456:Fluorescent Dyes; D002939:Ciprofloxacin