Screening of metal ion chelators against Leishmania donovani-infected Syrian hamsters

Leishmania donovani-infected Syrian hamsters were treated intraperitoneally with 0.23 mmoles/kg/day of EDTA; EGTA; HEEDTA and 100 mg/kg/day of Pentostam R. The control group received 0.1 ml of phosphate buffered saline. After 30 days of treatment; the animals were sacrificed. Of the Pentostam-treated animals; 5 out 6 had negative spleen cultures; while all the chelator and PBS-treated ones yielded parasites. While all the Pentostam-treated hamsters yielded had negative bone marrow cultures; only 1 out of 6 HEEDTA-treated hamsters yielded parasites. Spleen; liver and bone marrow parasite-loads calculated from chelator-treated animals were consistently significantly higher than for Pentostam-treated animals. These results suggest that although metal ion chelators have some antileishmanial potential; their in vivo activity against L. donovani is low compared to Pentostam

Comparison of Giemsa and acridine orange stains for the diagnosis of Leishmania donovani in biopsies of infected hamsters

Identical impression smears of spleen; liver and bone marrow biopsy materials from Leishmania donovani-infected hamsters were stained using either acridine orange or Giemsa. Spleen parasite-loads calculated from the two stains for identical biopsy material were significantly different from each other. However; liver and bone marrow parasite-loads calculated from either Giemsa-stained or acridine orange-stained biopsies were not significantly different from each other. This study has shown that acridine orange; which is a quick and simple technique; has great potential in the diagnosis of kala-azar when liver and bone marrow biopsies are used