| identification and analysis of dihydrofolate reductase alleles from plasmodium falciparum present at low frequency in polyclonal patient samples. | as resistance to chloroquine spreads in sub-saharan africa, pyrimethamine plus sulfadoxine (psd) is increasingly used as a first-line treatment for falciparum malaria. populations of plasmodium falciparum (pf) resistant to psd have been selected quickly in other regions. the resistance is strongly correlated with point mutations in dihydrofolate reductase (dhfr) and dihydropteroate synthase (dhps), the two targets of the drug. it is critical to identify drug-resistant pf-dhfr alleles that are pr ... | 1999 | 10432070 |