title: Integrated in vitro-in silico screening strategy for the discovery of antibacterial compounds.
abstract: Multidrug-resistant bacterial infections are an increasing source of healthcare problems, and the research for new antibiotics is currently unable to respond to this challenge. In this work, we present a screening strategy that integrates cell-based high-throughput screening (HTS) with in silico analogue search for antimicrobial small-molecule drug discovery. We performed an HTS on a diverse chemical library by using an assay based on a bioluminescent Escherichia coli K-12 (pTetLux1) strain. The HTS yielded eight hit compounds with >50% inhibition. These hits were then used for structural similarity-based virtual screening, and of the 29 analogues selected for in vitro testing, four compounds displayed potential activity in the pTetLux1 assay. The 11 most active compounds from combined HTS and analogue search were further assessed for antimicrobial activity against clinically important strains of E. coli and Staphylococcus aureus and for in vitro cytotoxicity against human cells. Three of the compounds displayed antibacterial activity and low human cell cytotoxicity. Additionally, two compounds of the set fully inhibited S. aureus growth after 24 h, but also exhibited human cell cytotoxicity in vitro.
authors.affiliation: 1 Centre for Drug Research, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki , Helsinki, Finland .
authors.forename: Susanna
authors.initials: S
authors.lastname: Nybond
authors.forename: Leo
authors.initials: L
authors.lastname: Ghemtio
authors.forename: Dorota A
authors.initials: DA
authors.lastname: Nawrot
authors.forename: Matti
authors.initials: M
authors.lastname: Karp
authors.forename: Henri
authors.initials: H
authors.lastname: Xhaard
authors.forename: Päivi
authors.initials: P
authors.lastname: Tammela
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000138:chemical synthesis; D001681:Biological Assay / Q000379:methods*; D002470:Cell Survival / Q000187:drug effects; D003198:Computer Simulation; D015195:Drug Design; D004353:Drug Evaluation, Preclinical / Q000379:methods; D004926:Escherichia coli / Q000166:cytology / Q000187:drug effects* / Q000502:physiology*; D057166:High-Throughput Screening Assays / Q000379:methods*; D008954:Models, Biological; D008956:Models, Chemical; D018511:Systems Integration; D013678:Technology, Pharmaceutical / Q000379:methods
chemical_list: D000900:Anti-Bacterial Agents