The aim of this study was to evaluate the Trypanosoma evansi susceptibility to amphotericin B in vitro and in vivo. Four concentrations (0.06, 0.25, 1.0, and 4.0µg mL-1) of amphotericin B were tested against a suspension containing T. evansi and phosphate buffer solution with glucose in the in vitro assay. Fifteen rats infected with T. evansi were used for the in vivo assay. Groups A (n=5) and B (n=5) received daily doses of 1 and 3mg kg-1 during 10 days and the parasitemia was estimated daily by microscopic examination of smears. The rats from group C (n=5) were the positive control and were infected but not treated. Rats from group D (n=5) were used as negative control. in vitro assays showed a 100% of susceptibility of T. evansi to amphotericin B after 7 hours, at all concentrations tested. The higher dose tested did not cure the rats, although treated rats had a longer life span in comparison to the non-treated group. Adverse effects on renal and hepatic hemodynamics were also researched. Biochemical parameters obtained were within the normal ranges. It was concluded that T. evansi is susceptible to amphotericin B in vitro. The dose of 3 mg kg-1 tested in rats increased life span, but did not cure the animals.
Trypanosomosis; treatment; antibiotic; rats
