title: High-throughput screening for small-molecule inhibitors of Staphylococcus epidermidis RP62a biofilms.
abstract: High-throughput screening (HTS) of 42 865 compounds was performed to identify compounds that inhibit formation of or kill Staphylococcus epidermidis RP62a biofilms. Three biological processes were assayed, including (1) growth of planktonic/biofilm bacteria, (2) assessment of metabolically active biofilm bacteria using a resazurin assay, and (3) assessment of biofilm biomass by crystal violet staining. After completing the three tiers (primary screening, hit confirmation, and dose-response curves), 352 compounds (representing ~0.8%) were selected as confirmed hit compounds from the HTS assay. The compounds were divided into groups based on their effectiveness on S. epidermidis biofilm properties. The majority of these affected both inhibition and killing of bacterial biofilm cultures. Only 16 of the confirmed hit compounds that have either an AC50 lower than 10 µM and/or Sconst ≥70 from those processed were selected for further study by confocal laser scanning microscopy (CLSM). The CLSM was used to evaluate the confirmed hit compounds on (1) inhibition of biofilm formation and (2) killing of preexisting S. epidermidis biofilms. Taken together, with further testing (e.g., disease-related conditions), such compounds may have applications as broad antimicrobial/antibiofilm use for prophylactic or therapeutic intervention to combat infections in surgical and intensive care clinics and battlefield settings.
authors.affiliation: Department of Molecular Genetics, Biochemistry and Microbiology, College of Medicine, University of Cincinnati, Cincinnati, OH 45433-7913, USA.
authors.forename: Warunya
authors.initials: W
authors.lastname: Panmanee
authors.forename: Deborah
authors.initials: D
authors.lastname: Taylor
authors.forename: Chloe J A
authors.initials: CJ
authors.lastname: Shea
authors.forename: Hong
authors.initials: H
authors.lastname: Tang
authors.forename: Sandra
authors.initials: S
authors.lastname: Nelson
authors.forename: William
authors.initials: W
authors.lastname: Seibel
authors.forename: Ruben
authors.initials: R
authors.lastname: Papoian
authors.forename: Ryan
authors.initials: R
authors.lastname: Kramer
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Hassett
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Lamkin
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects*; D057166:High-Throughput Screening Assays / Q000379:methods*; D006801:Humans; D020128:Inhibitory Concentration 50; D008826:Microbial Sensitivity Tests / Q000379:methods*; D018613:Microscopy, Confocal; D054852:Small Molecule Libraries; D013212:Staphylococcus epidermidis / Q000187:drug effects* / Q000502:physiology
chemical_list: D000900:Anti-Bacterial Agents; D054852:Small Molecule Libraries
keywords: S. epidermidis RP62a; biofilms; high-throughput screening; inhibition; killing