EFFECTS OF MANGANESE SALTS ON THE AIDS-RELATED PATHOGEN, CRYPTOSPORIDIUM-PARVUM IN-VITRO AND IN-VIVO

The authors examined the effects of manganese salts on the interaction of the AIDS-related pathogen, Cryptosporidium parvum, with human ileo adenocarcinoma (HCT-8) cells in vitro. Manganese (Mn) inhibited bindin g of C, parvum sporozoite membrane antigens to intact, fixed HCT-8 cel ls in a dose-dependent fashion, whereas Ca++, Mg++, and Zn++ salts had no effect. Manganese was also found to affect sporozoite penetration of live HCT-8 cells, which resulted in a dose-dependent inhibition of parasite development. However, the levels of Mn++ needed in the live c ell assays was approx 10-fold greater than in the fixed-cell assays. T his inhibition of parasite development was not reversible when Ca++ or Mg++ were used as competitors. Oral supplementation of suckling mice infected with C. parvum with MnSO4 resulted in significant reductions and, in some cases, elimination of intestinally derived oocysts.