Chloroquine and sulphadoxine-pyrimethamine sensitivity of Plasmodium falciparum parasites in a Brazilian endemic area

Background The goal of the present study was the characterization of Plasmodium falciparum genes associated to malaria drug resistance ( pfcrt , pfdhfr and pfdhps) , in samples from two Brazilian localities. Methods Parasites from 65 P. falciparum samples were genotyped using nested-PCR and direct DNA sequencing. Results Six resistant sulphadoxine-pyrimethamine (SP) pfdhfr genotypes and one haplotype associated to SP sensitivity were detected. For pfcrt gene, SVMNT chloroquine (CQ)-resistant genotype was detected as well as the CVMNK CQ-sensitive haplotype in the same sample from Paragominas, that showed a SP-sensitive genotype. Conclusion This study is the first to document the sensitivity of P. falciparum parasites to CQ and SP in Brazilian field samples. The importance of these findings is discussed.