title: High-throughput Giardia lamblia viability assay using bioluminescent ATP content measurements.
abstract: The human pathogen Giardia lamblia is an anaerobic protozoan parasite that causes giardiasis, one of the most common diarrheal diseases worldwide. Although several drugs are available for the treatment of giardiasis, drug resistance has been reported and is likely to increase, and recurrent infections are common. The search for new drugs that can overcome the drug-resistant strains of Giardia is an unmet medical need. New drug screen methods can facilitate the drug discovery process and aid with the identification of new drug targets. Using a bioluminescent ATP content assay, we have developed a phenotypic drug screen method to identify compounds that act against the actively growing trophozoite stage of the parasite. This assay is homogeneous, robust, and suitable for high-throughput screening of large compound collections. A screen of 4,096 pharmacologically active small molecules and approved drugs revealed 43 compounds with selective anti-Giardia properties, including 32 previously reported and 11 novel anti-Giardia agents. The most potent novel compound was fumagillin, which showed 50% inhibitory concentrations of 10 nM against the WB isolate and 2 nM against the GS isolate.
authors.affiliation: NIH Chemical Genomics Center, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland 20892-3370, USA.
authors.forename: Catherine Z
authors.initials: CZ
authors.lastname: Chen
authors.forename: Liudmila
authors.initials: L
authors.lastname: Kulakova
authors.forename: Noel
authors.initials: N
authors.lastname: Southall
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Marugan
authors.forename: Andrey
authors.initials: A
authors.lastname: Galkin
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Austin
authors.forename: Osnat
authors.initials: O
authors.lastname: Herzberg
authors.forename: Wei
authors.initials: W
authors.lastname: Zheng
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D000981:Antiprotozoal Agents / Q000494:pharmacology*; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D003510:Cyclohexanes / Q000494:pharmacology; D055808:Drug Discovery / Q000379:methods; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology; D016829:Giardia lamblia / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D057166:High-Throughput Screening Assays / Q000379:methods*; D006801:Humans; D008163:Luminescent Measurements; D021261:Parasitic Sensitivity Tests / Q000379:methods; D012717:Sesquiterpenes / Q000494:pharmacology; D053058:Trophozoites / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism
chemical_list: D000981:Antiprotozoal Agents; D003510:Cyclohexanes; D005231:Fatty Acids, Unsaturated; D012717:Sesquiterpenes; C026211:fumagillin; D000255:Adenosine Triphosphate