title: Entamoeba histolytica: changes in the zymodeme of cloned nonpathogenic trophozoites cultured under different conditions.
abstract: In this paper we report the occurrence of changes in the migration of certain isoenzymes of a cloned strain (MAV-CINVESTAV) of Entamoeba histolytica. This strain was isolated from an asymptomatic carrier and showed an initial nonpathogenic zymodeme I. The transfer of polyxenic trophozoites from Robinson's medium (7% serum) to Jones' medium (30% serum) provoked changes in isoenzyme expression, resulting in the conversion of zymodeme I to a zymodeme that was similar to the XVII zymodeme except for two slow-running bands and a single fast-running band that were detected for hexokinase (HK). This XVII-like zymodeme reverted to zymodeme I when trophozoites were cultured under monoxenic conditions in TY1-S-33 medium (10% serum). When we cultured cloned strain MAV-CINVESTAV under axenic conditions in TY1-S-33 medium, trophozoites expressed a pathogenic zymodeme with two fast-running HK bands and a beta-phosphoglucomutase band. In addition, phagocytosis and the ability of the trophozoites to destroy cell-culture monolayers were expressed only in trophozoites cultured under axenic conditions. The axenization procedure required the presence of live Fusobacterium symbiosum and is also described herein.
authors.affiliation: Department of Experimental Pathology, CINVESTAV I.P.N., Mexico, D.F.
authors.forename: M A
authors.initials: MA
authors.lastname: Vargas
authors.forename: E
authors.initials: E
authors.lastname: Orozco
mesh_terms: D000818:Animals; D004748:Entamoeba histolytica / Q000145:classification / Q000201:enzymology* / Q000254:growth & development / Q000472:pathogenicity; D006593:Hexokinase / Q000235:genetics* / Q000378:metabolism; D007527:Isoenzymes / Q000235:genetics* / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D010641:Phenotype; D010733:Phosphoglucomutase / Q000235:genetics* / Q000378:metabolism; D013045:Species Specificity; D014774:Virulence
chemical_list: D007527:Isoenzymes; D006593:Hexokinase; D010733:Phosphoglucomutase; D010100:Oxygen