title: Early stage efficacy and toxicology screening for antibiotics and enzyme inhibitors.
abstract: The rise in organisms resistant to existing drugs has added urgency to the search for new antimicrobial agents. Aspartate β-semialdehyde dehydrogenase (ASADH) catalyzes a critical step in an essential microbial pathway that is absent in mammals. Our laboratory is using fragment library screening to identify efficient and selective ASADH inhibitors. These preliminary agents are then tested to identify compounds with desired antimicrobial properties for further refinement. Toward this end, we have established a microplate-based, dual-assay approach using a single reagent to evaluate antibiotic activity and mammalian cell toxicity during early stage development. The bacterial assay uses nonpathogenic bacteria to allow efficacy testing without a dedicated microbial laboratory. Toxicity assays are performed with a panel of mammalian cells derived from representative susceptible tissues. These assays can be adapted to target other microbial systems, such as fungi and biofilms, and additional mammalian cell lines can be added as needed. Application of this screening approach to antibiotic standards demonstrates the ability of these assays to identify bacterial selectivity and potential toxicity issues. Tests with selected agents from the ASADH inhibitor fragment library show some compounds with antibiotic activity, but as expected, most of these early agents display higher than desired mammalian cell toxicity.
authors.affiliation: Center for Drug Design and Development, University of Toledo, Toledo, OH, USA. jeffrey.sarver@utoledo.edu
authors.forename: Jeffrey G
authors.initials: JG
authors.lastname: Sarver
authors.forename: Jill A
authors.initials: JA
authors.lastname: Trendel
authors.forename: Nicole R
authors.initials: NR
authors.lastname: Bearss
authors.forename: Lin
authors.initials: L
authors.lastname: Wang
authors.forename: Amarjit
authors.initials: A
authors.lastname: Luniwal
authors.forename: Paul W
authors.initials: PW
authors.lastname: Erhardt
authors.forename: Ronald E
authors.initials: RE
authors.lastname: Viola
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000633:toxicity; D001223:Aspartate-Semialdehyde Dehydrogenase / Q000037:antagonists & inhibitors*; D002460:Cell Line; D004791:Enzyme Inhibitors / Q000494:pharmacology* / Q000633:toxicity; D006801:Humans; D020128:Inhibitory Concentration 50; D008826:Microbial Sensitivity Tests / Q000379:methods*; D015203:Reproducibility of Results
chemical_list: D000900:Anti-Bacterial Agents; D004791:Enzyme Inhibitors; D001223:Aspartate-Semialdehyde Dehydrogenase