title: Auxotrophy to lipoproteins of Entamoeba histolytica cultivated under axenic conditions.
abstract: Entamoeba histolytica grows in media without serum but with a mixture of aminoacids, vitamins, lipoproteins, free cholesterol, phospholipids and fatty acids called PACSR. The ability of lipoproteins and free lipids to support growth of three E. histolytica strains (HK9, HMI:IMSS and HM3:IMSS) was analysed. Tubes containing 5 ml culture medium, amino acids, vitamins and either 120-1,200 microg lipoproteins/ml or 0.017-0.10 mg free lipids/ml (predissolved in absolute ethanol) were inoculated with 1x10(4) trophozoites/ml and incubated at 37 degrees C for 72 h. Amoebae died within 12 h in the presence of any free lipid combination, while those having 240-480 mg lipoproteins/ml reached densities similar to or higher than those of controls (depending on strain). The addition of ethanol (0.1%) to the media produced stable lipid solutions and did not show significant adverse effects. Accordingly, E. histolytica is auxotrophic to lipoproteins and unable to use free cholesterol, phospholipids or fatty acids.
authors.affiliation: Centro de Investigación Biomédica del Noreste, Instituto Mexicano del Seguro Social, División de Bíologia Celular y Molecular, Administración de Correos No. 4, Monterrey, México.
authors.forename: B D
authors.initials: BD
authors.lastname: Mata-Cárdenas
authors.forename: J
authors.initials: J
authors.lastname: Vargas-Villarreal
authors.forename: H G
authors.initials: HG
authors.lastname: Martínez-Rodríguez
authors.forename: J
authors.initials: J
authors.lastname: Castro-Garza
authors.forename: M T
authors.initials: MT
authors.lastname: González-Garza
authors.forename: S
authors.initials: S
authors.lastname: Said-Fernández
mesh_terms: D000818:Animals; D002784:Cholesterol / Q000378:metabolism / Q000494:pharmacology; D003470:Culture Media; D016895:Culture Media, Serum-Free; D004748:Entamoeba histolytica / Q000254:growth & development* / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism / Q000494:pharmacology; D050356:Lipid Metabolism; D008055:Lipids / Q000494:pharmacology; D008074:Lipoproteins / Q000378:metabolism* / Q000494:pharmacology; D010743:Phospholipids / Q000378:metabolism / Q000494:pharmacology
chemical_list: D003470:Culture Media; D016895:Culture Media, Serum-Free; D005227:Fatty Acids; D008055:Lipids; D008074:Lipoproteins; D010743:Phospholipids; D002784:Cholesterol