Susceptibility studies of Malaysian Plasmodium falciparum clones to type II antifolate drugs after 3 years of continuous in vitro culture

Exposure of Plasmodium falciparum to increasing sublethal drug concentrations followed by drug treatment led to the development of many resistant parasites. Therefore, the susceptibility of these clones to the type II antifolate drugs, cycloguanil and pyrimethamine, before and after subculturing them in vitro for a period of 3 years, was studied.