Hydroxyurea inhibits intracellular Toxoplasma gondii multiplication

Tachyzoites of Toxoplasma gondii multiply within the parasitophorous vacuol e (PV) until the lysis of the host cell. This study was undertaken to evalu ate the effect of hydroxyurea (a specific drug that arrests cell division a t G1/S phase) on the multiplication of T. gondii tachyzoites in infected Ve ro cells. Infected host cells were treated with hydroxyurea for periods var ying from 5 to 48 h, and the survival and morphology of the parasite were d etermined. Hydroxyurea arrested intracellular T. gondii multiplication in a ll periods tested. After 48 h of incubation with hydroxyurea, intracellular parasites were not easily observed in Vero cells. Ultrastructural observat ions showed that infected host cells treated with hydroxyurea for 24 h or m ore presented disrupted intracellular parasites within the PV. However, the host cells exhibited a normal morphology. Our observations suggest that hy droxyurea was able to interfere with the cycle of the intracellular parasit e, leading to the complete destruction of the T. gondii without affecting t he host cells. (C) 2000 Federation of European Microbiological Societies. P ublished by Elsevier Science B.V. All rights reserved.