title: Variation in growth and drug susceptibility among Giardia duodenalis assemblages A, B and E in axenic in vitro culture and in the gerbil model.
abstract: This study investigated the molecular and biological variation among different Giardia duodenalis assemblages. In vitro growth and susceptibility to albendazole, fenbendazole, flubendazole, metronidazole, tinidazole and furazolidone was studied for laboratory (AI: WB, AII: G1 and B: GS/M-83-H7) and 6 field isolates of assemblage subtype AI, AII, B and EIII. Additionally, isolates of the 3 assemblages were evaluated in the gerbil upon 3-day oral treatment with albendazole (6 mg/kg), flubendazole (5 mg/kg) and metronidazole (20 mg/kg). Assemblage AI grew significantly faster than all other assemblage subtypes, which showed comparable generation times. The assemblage A laboratory strains displayed altered in vitro drug susceptibilities compared to their matching AI or AII field isolate. No variation in drug susceptibility was observed between field isolates of assemblages A and E. However, assemblage A laboratory strains were more susceptible to the benzimidazoles and less susceptible to the nitro-imidazoles and furazolidone than the assemblage B laboratory strain. In the gerbil, no markedly different drug susceptibilities were observed. In conclusion, the Giardia assemblage subtype can be associated with differences in growth characteristics rather than in drug susceptibility.
authors.affiliation: Laboratory of Microbiology, Parasitology and Hygiene (LMPH), Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, B-2020 Antwerp, Belgium.
authors.forename: E
authors.initials: E
authors.lastname: Bénéré
authors.forename: T
authors.initials: T
authors.lastname: VAN Assche
authors.forename: P
authors.initials: P
authors.lastname: Cos
authors.forename: L
authors.initials: L
authors.lastname: Maes
mesh_terms: D000818:Animals; D000940:Antigenic Variation; D000953:Antigens, Protozoan / Q000032:analysis / Q000276:immunology; D000981:Antiprotozoal Agents / Q000494:pharmacology*; D061245:Axenic Culture; D049109:Cell Proliferation / Q000187:drug effects; D004195:Disease Models, Animal; D004351:Drug Resistance; D005838:Genotype; D005849:Gerbillinae; D016829:Giardia lamblia / Q000145:classification / Q000187:drug effects* / Q000254:growth & development / Q000276:immunology / Q000302:isolation & purification; D005873:Giardiasis / Q000188:drug therapy / Q000469:parasitology; D020128:Inhibitory Concentration 50; D008297:Male; D013045:Species Specificity; D053058:Trophozoites / Q000187:drug effects* / Q000254:growth & development
chemical_list: D000953:Antigens, Protozoan; D000981:Antiprotozoal Agents