title: New insect system for testing antibiotics.
abstract: New and efficient methods to screen antibiotics are needed to counter increased antibiotic resistance in pathogens and the emergence of new diseases. Here we report a new insect model for screening antibiotics in vivo using the grasshopper Romalea microptera. The system is inexpensive, efficient, and flexible, avoids animal-welfare problems, and can be used to test against most major pathogenic groups. We employed this system to test 11 commercial antibiotics against a pathogenic Encephalitozoon species (Microsporidia). Oral treatment with fumagillin or thiabendazole significantly reduced pathogen spore counts, whereas spore counts of grasshoppers fed with albendazole, ampicillin, chloramphenicol, griseofulvin, metronidazole, sulfadimethoxine, or tetracycline were not significantly different from the infected controls. Quinine produced a distinct, but nonsignificant, reduction in spores, and streptomycin a nonsignificant increase in spores. Although 2 antibiotics significantly reduced spore counts, in no case was the pathogen totally eliminated. This study demonstrates the validity of this system as a method to screen antibiotics. It also corroborates the difficulty researchers and physicians have had in treating microsporidia infections, and suggests that quinine and related alkaloid compounds should be further examined as possible therapeutic agents against this group of ubiquitous pathogens. In addition, streptomycin and related compounds should be tested to determine if this widely used antibiotic enhances microsporidiosis.
authors.affiliation: Department of Biology, Illinois State University, Normal, Illinois 61790-4120, USA.
authors.forename: Shajahan
authors.initials: S
authors.lastname: Johny
authors.forename: Carlos E
authors.initials: CE
authors.lastname: Lange
authors.forename: Leellen F
authors.initials: LF
authors.lastname: Solter
authors.forename: Amber
authors.initials: A
authors.lastname: Merisko
authors.forename: Douglas W
authors.initials: DW
authors.lastname: Whitman
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology*; D000935:Antifungal Agents / Q000494:pharmacology; D003365:Costs and Cost Analysis; D003510:Cyclohexanes / Q000494:pharmacology; D004353:Drug Evaluation, Preclinical / Q000191:economics / Q000941:ethics / Q000379:methods*; D016819:Encephalitozoon / Q000187:drug effects* / Q000254:growth & development; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology; D006110:Grasshoppers / Q000382:microbiology*; D008297:Male; D023421:Models, Animal; D011803:Quinine / Q000494:pharmacology; D012717:Sesquiterpenes / Q000494:pharmacology; D013827:Thiabendazole / Q000494:pharmacology
chemical_list: D000890:Anti-Infective Agents; D000935:Antifungal Agents; D003510:Cyclohexanes; D005231:Fatty Acids, Unsaturated; D012717:Sesquiterpenes; C026211:fumagillin; D011803:Quinine; D013827:Thiabendazole