RESUMO
Anti-malarial resistance in Plasmodium falciparum remains an obstacle for malaria control. Resistance-associated genes were analysed in Brazilian samples over four decades to evaluate the impact of different treatment regimens on the parasite genetic profile. Methods: Samples were collected on filter paper from patients infected in the Amazon region from 1984 to 2011.DNA was extracted with Chelex® 100 and monoinfection confirmed by PCR. SNPs in the pfcrt, pfmdr1, pfdhfr and pfdhpsgenes were assessed by PCR-RFLP. The pfmdr1 copy number was estimated using real time quantitative PCR with SYBR®Green. Parasite response was assessed ex vivo with seven concentrations of each anti-malarial. Patients were treatedaccording to Brazilian guidelines: quinine plus tetracycline or mefloquine in period 1 and ACT in period 2...