title: Entamoeba dispar: cultivation with sterilized Crithidia fasciculata.
abstract: Four isolates of Entamoeba dispar identified by their hexokinase and phosphoglucomutase isoenzyme profile and by their failure to react with Entamoeba histolytica-specific monoclonal antibody (4G6) could be grown in either Diamond's BI-S-33 medium, newly developed BCSI-S (Biosate cysteine starch iron-serum) medium, or casein-free YI-S medium in the presence of Crithidia fasciculata (ReF-1:PRR) sterilized by heating 56 degrees C for 30 min and subsequent incubation with 1% hydrogen peroxide for 24 hours at 4 degrees C. After the cultures were maintained for over 50 passages, the amebae were identified as E. dispar by isoenzyme analysis, polymerase chain reaction with E. histolytica- and E. dispar-specific primers, i.e. p11 plus p12 and p13 plus p14, respectively, and by negative reactivity with monoclonal antibody 4G6. The flagellates added to the culture were judged to be metabolically inactive based on the results of nuclear magnetic resonance spectroscopy, electron microscopy, and polarographic analysis. All of these findings suggest that E. dispar can grow in vitro with metabolically inactive C. fasciculata as a culture associate.
authors.affiliation: Department of Tropical Medicine and Parasitology, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Kobayashi
authors.forename: E
authors.initials: E
authors.lastname: Imai
authors.forename: H
authors.initials: H
authors.lastname: Tachibana
authors.forename: T
authors.initials: T
authors.lastname: Fujiwara
authors.forename: T
authors.initials: T
authors.lastname: Takeuchi
mesh_terms: D000818:Animals; D016831:Crithidia fasciculata / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure; D004747:Entamoeba / Q000254:growth & development*; D004749:Entamoebiasis / Q000469:parasitology; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy; D008854:Microscopy, Electron; D016877:Oxidants / Q000494:pharmacology; D011048:Polarography; D016133:Polymerase Chain Reaction; D011323:Primates; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000502:physiology; D013242:Sterilization
chemical_list: D016877:Oxidants; D006861:Hydrogen Peroxide