Plasmodium vinckei: production of chloroquine-resistant strain.

摘要: Abstract To date only two species of malarial parasites, Plasmodium falciparum in man and P. berghei mice, have demonstrated the ability to develop a high degree resistance chloroquine. A strain vinckei which is resistant maximum tolerated dose (MTD) chloroquine mice has been selected from pyrimethamine-resistant parent strain. Groups five or more were treated with varying doses drug for 3–4 days starting day after parasite inoculation. Subpassages made highest that allowed some development parasites. Resistance developed gradually during 37 successive chloroquine-treated passages over period about 44 weeks. In subsequent passages, was MTD (200 mg/kg/day). The suppressed by 99.9% on Day 7 5 mg/kg/day 4 days. Sixty percent 10 all 20 greater cured. Associated parasite's failure produce detectable pigment appearance multiple vacuoles. characterized slower developing, less fatal parasitemias while untreated fulminating infections often result death. This new chloroquine-resistant malaria may be value as laboratory model study acquired resistance.