Cadernos de Saúde Pública
On-line version ISSN 1678-4464
Print version ISSN 0102-311X
VIANA, Giselle Maria Rachid; MACHADO, Ricardo Luís Dantas; CALVOSA, Vanja Sueli Pachiano and POVOA, Marinete Marins. Mutations in the pfmdr1, cg2, and pfcrt genes in Plasmodium falciparum samples from endemic malaria areas in Rondonia and Pará State, Brazilian Amazon Region. Cad. Saúde Pública [online]. 2006, vol.22, n.12, pp.2703-2711. ISSN 1678-4464. http://dx.doi.org/10.1590/S0102-311X2006001200019.
The objectives of this study were to investigate the molecular basis for Plasmodium falciparum resistance to chloroquine in isolates from the Brazilian Amazon and to identify polymorphisms in the pfmdr1 gene, codons 184, 1042, and 1246, the kappa and gamma regions of the cg2 gene, and the K76T mutation of the pfcrt gene, in order to calculate the distribution of polymorphism within each target gene, comparing samples from distinct geographic areas, using allele-specific polymerase chain reaction (PCR) for the pfmdr gene and PCR plus restriction fragment length polymorphism (RFLP) for the cg2 and pfcrt genes. The sample consisted of 40 human blood isolates, already collected and morphologically diagnosed as carriers of P. falciparum parasites, from four localities: Porto Velho in Rondonia State and Maraba, Itaituba, and Tailandia in Pará State. Distribution of P. falciparum in vitro chloroquine resistance in the isolates was 100% for pfmdr1, cg2 gamma region, and pfcrt, except for the polymorphism in the cg2 kappa region, which was not found.
Keywords : Plasmodium falciparum; Genetic Polymorphism; Chloroquine.