Los trofozoitos de Entamoeba histolytica internalizan a Trichomonas vaginalis

The human pathogenic protozoa Entamoeba histolytica adheres to cells inducing lysis and further E. histolytica phagocytosis. The present paper describes interaction process and E. histolytica mechanism of internalization of Trichomonas vaginalis into its cytoplasm. Both protozoa were individually cultured in TYI-S-33 with adult bovine serum and vitamin supplement for 72 h at 37°C. One ml of each culture was then incubated in Eppendorf tubes at 37°C and two samples were obtained every 30 seconds for a period of four minutes. All samples were fixed with a Karnovsky buffer solution and post fixed with 1% Osmiun tetroxide for 30 minutes. Part of the samples were dehydrated and further embedded in Araldite resin and studied with a light microscope. A sample of each time period was analyzed under Nomarski contrast microscopy technique. We observed four different interactions between E. histolytica and T. vaginalis namely; 1) Adhesion of both protozoa, 2) organization of a duct within the E. histolytica cytoplasm, 3) Internalization of T. vaginalis into the cytoplasm of E. histolytica and 4) Strangulation of the incorporated vesicle giving rise to two vesicles. One of the vesicles contained a granular matrix and the other was agranular, with a progressive diminish of the protozoa size. The observed steps of internalization of T. vaginalis into E.histolytica suggest an attack mechanism of the last for live cells.