Molecular Surveillance for Polymorphisms Associated with Artemisinin-Based Combination Therapy Resistance in Plasmodium falciparum Isolates Collected in the State of Roraima, Brazil

Abstract

Given that the C580Y polymorphism in the <i>Plasmodium falciparum</i> propeller domain of the <i>kelch 13</i> gene (<i>pfk13</i>) was documented in Guyana, monitoring for mutations associated with antimalarial resistance was undertaken in neighboring Roraima state in Brazil. Polymorphisms in the <i>pfmdr1</i> and <i>pfk13</i> genes were investigated in 275 <i>P. falciparum</i> samples. No <i>pfk13</i> mutations were observed. Triple mutants 184F, 1042D, and 1246Y were observed in 100% of the samples successfully sequenced for the <i>pfmdr1</i> gene, with 20.1% of these having an additional mutation at codon 1034C. Among them, 2.5% of samples harbored two copies of the <i>pfmdr1</i> gene. We found no evidence of the spread of C580Y parasites to Roraima state, Brazil. As previously observed, the 184F, 1042D, and 1246Y mutations in the <i>pfmdr1</i> gene appear to be fixed in this region. Continued molecular surveillance is essential to detect any potential migration or local emergence of artemisinin-resistant mutation.