Mepacrine- and Primaquine-resistant Strains of Plasmodium berghei, Vincke and Lips, 1948

Abstract

THE demonstration that the mechanism of pigment formation in the rodent malaria parasite, Plasmodium berghei, could be disturbed when the parasites became resistant to the antimalarial drug, chloroquine^1,2, has since been confirmed by Thompson et al.³. The same phenomenon has now been described by Jacobs in a quinine-resistant strain⁴. In continuation of our own investigations we have developed two further strains of P. berghei, one of which, the P strain, has a high level of primary resistance to the 8-aminoquinoline compound, primaquine, and the second, the M strain, a high level of primary resistance to the familiar 9-aminoacridine derivative, mepacrine. The methods followed for the induction of drug-resistance in these strains and their subsequent testing for sensitivity to various drugs are identical to those used with the chloroquine-resistant (RC) strain and have been described elsewhere⁵. Preliminary examination of the ultrastructure of parasites of the P and M strains has been made in association with Dr. W. Stäubli, following the techniques already published².