title: Evaluation of high-throughput assays for in vitro drug susceptibility testing of Tritrichomonas foetus trophozoites.
abstract: Tritrichomonas foetus is a sexually transmitted protozoan parasite that causes abortions in cattle and results in severe economic losses. In the United States, there are no safe and effective treatments for this parasite and infected animals are typically culled. In order to expedite drug discovery efforts, we investigated in vitro trophozoite killing assays amenable to high-throughput screening in 96 well plate formats. We evaluated the reduction of resorufin, incorporation of propidium iodide, and a luminescence-based ATP detection assay. Of these methods, reduction of resorufin was found to be the most reliable predictor of trophozoite concentrations. We further validated this method by conducting dose-response experiments suitable for calculation of EC50 values for two established compounds with known activity against trophozoites in vitro, namely, metronidazole and ronidazole. Our results demonstrate that the resorufin method is suitable for high-throughput screening and could be used to enhance efforts targeting new treatments for bovine trichomoniasis.
authors.affiliation: Department of Veterinary Pathology, College of Veterinary Medicine, Iowa State University, Ames, IA, USA.
authors.forename: Chris
authors.initials: C
authors.lastname: Bader
authors.affiliation: Department of Veterinary Pathology, College of Veterinary Medicine, Iowa State University, Ames, IA, USA.
authors.forename: Jeba
authors.initials: J
authors.lastname: Jesudoss Chelladurai
authors.affiliation: Department of Veterinary Pathology, College of Veterinary Medicine, Iowa State University, Ames, IA, USA.
authors.forename: Kylie
authors.initials: K
authors.lastname: Thompson
authors.affiliation: Department of Veterinary Pathology, College of Veterinary Medicine, Iowa State University, Ames, IA, USA.
authors.forename: Cindy
authors.initials: C
authors.lastname: Hall
authors.affiliation: Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, USA.
authors.forename: Steve A
authors.initials: SA
authors.lastname: Carlson
authors.affiliation: Department of Veterinary Pathology, College of Veterinary Medicine, Iowa State University, Ames, IA, USA. Electronic address: brewermt@iastate.edu.
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Brewer
mesh_terms: D000871:Anthelmintics / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D057166:High-Throughput Screening Assays / Q000662:veterinary*; D008163:Luminescent Measurements / Q000662:veterinary*; D061848:Optical Imaging; D016835:Tritrichomonas foetus / Q000187:drug effects*; D053058:Trophozoites / Q000187:drug effects*
chemical_list: D000871:Anthelmintics
keywords: Drug susceptibility assay; High-throughput screening; Trichomoniasis; Trophozoite drug screening