title: Cytomorphological changes and susceptibility of clinical isolates of Acanthamoeba spp. to heterocyclic alkylphosphocholines.
abstract: The treatment of diseases caused by pathogenic strains of Acanthamoeba spp. is to date limited and frequently unsuccessful. Alkylphosphocholines (APCs) are promising agents with interesting results of antiparasitic activity in experimental and clinical conditions. In the present study susceptibilities of two clinical isolates of Acanthamoeba spp. to four heterocyclic APCs were investigated. The isolates showed high degrees of susceptibility to studied APCs and all the tested concentrations inhibited the growth with the highest concentrations of 500-1000μM causing 100% eradication of the trophozoites and cysts. The highest susceptibility was noted in IF16-P-4-Pip with EC50 values of 28.62-43.73μM, and EC90 values of 30.70-63.16μM after 48h of incubation. The cytomorphological changes of trophozoites after the exposure to APCs included rounding up of cells, resorption of acanthopodia and subsequent lysis. The remains of cells were typical with oval shape and identifiable nucleus. After the application of IF16-P-4-Pip, IF16-P-2-MetPip, and IF16-P-Azep, at concentrations of 62.5-125μM to trophozoite suspension, a formation of pseudocysts was detected. The single-layered coat covering the surface of pseudocyst stained positively with a fluorescence brightener, Rylux. Destroyed cysts were characteristic with shrinkage of the cytoplasm and separation of the cytoplasmic membrane from the endocyst. IF16-P-2-MetPip at the highest concentration formed large spherical vesicles which frequently enclosed inactivated cysts. Heterocyclic APCs used in the study demonstrated strong amoebicidal activity and the cytotoxic effect of IF16-P-4-Pip similar to that of miltefosine indicates its possible therapeutic potential.
authors.affiliation: Department of Zoology, Faculty of Natural Sciences, Comenius University, Bratislava, Slovakia. Electronic address: garajova@fns.uniba.sk.
authors.forename: Mária
authors.initials: M
authors.lastname: Garajová
authors.affiliation: Department of Zoology, Faculty of Natural Sciences, Comenius University, Bratislava, Slovakia. Electronic address: mrva@fns.uniba.sk.
authors.forename: Martin
authors.initials: M
authors.lastname: Mrva
authors.affiliation: Department of Chemical Theory of Drugs, Faculty of Pharmacy, Comenius University, Bratislava, Slovakia. Electronic address: timko@fpharm.uniba.sk.
authors.forename: Lukáš
authors.initials: L
authors.lastname: Timko
authors.affiliation: Department of Chemical Theory of Drugs, Faculty of Pharmacy, Comenius University, Bratislava, Slovakia. Electronic address: lukac@fpharm.uniba.sk.
authors.forename: Miloš
authors.initials: M
authors.lastname: Lukáč
authors.affiliation: HPL Ltd., Department of Parasitology, Microbiological Laboratory, Bratislava, Slovakia. Electronic address: ondriska@hpl.sk.
authors.forename: František
authors.initials: F
authors.lastname: Ondriska
mesh_terms: D000048:Acanthamoeba / Q000166:cytology / Q000187:drug effects*; D006571:Heterocyclic Compounds / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D007634:Keratitis / Q000150:complications / Q000382:microbiology / Q000469:parasitology*; D033661:Oocysts / Q000166:cytology / Q000187:drug effects; D010767:Phosphorylcholine / Q000737:chemistry / Q000494:pharmacology*; D011552:Pseudomonas Infections / Q000150:complications / Q000382:microbiology; D011550:Pseudomonas aeruginosa; D015423:Scleritis / Q000150:complications; D053058:Trophozoites / Q000166:cytology / Q000187:drug effects
chemical_list: D006571:Heterocyclic Compounds; D010767:Phosphorylcholine
keywords: Acanthamoeba; Alkylphosphocholines; Cytotoxicity; Pseudocysts; Susceptibility