Toxoplasma gondii: Selective killing of extracellular parasites by oxidation using pyrrolidine dithiocarbamate

Extracellular Toxoplasma parasites are sensitive to pyrrolidine dithiocarba mate (PDTC) at low micromolar concentrations. Loss of parasite viability fo llowing PDTC treatment is shown to be mediated by oxidation, which is remin iscent of PDTC killing in mammalian cells. Intracellular parasites, by cont rast, are resistant to PDTC killing, although treatment does cause reversib le growth arrest. In addition to the possible implications relative to the biology of the parasite, these observations suggest that PDTC could be of u se in eliminating undesired extracellular parasites during assays and selec tions in vitro. (C) 2001 Academic Press.