Status of Artemisinin Resistance in Malaria Parasite from Molecular Analyses of the Gene in Southwestern Nigeria.

Evolution and spread of malaria parasite capable of evading antimalarials are the prime concern to malaria control. The currently effective drug, artemisinin (ART), is under threat due to detection of ART-resistant parasites in the Southeast Asian countries. It has been shown that amino acid (AA) mutations at the () gene provide resistance to ART. Nigeria, a part of the Sub-Saharan Africa, is highly endemic to malaria, contributing quite significantly to malaria, and resistance to chloroquine (CQ) and sulfadoxine-pyrimethamine (SP) combination drugs has already been reported. Since artemisinin combined therapy (ACT) is the first-line drug for treatment of uncomplicated malaria in Nigeria and five amino acid mutations have been validated in the gene alongside with candidate mutations for ART resistance, we performed molecular surveillance for mutations (following PCR and DNA sequence analyses) in this gene from two southwestern states of Nigeria. Statistical analyses of DNA sequences were also performed following different evolutionary models. None of the different validated and candidate AA mutations of gene conferring resistance to ART could be detected in sampled in the two southwestern states of Nigeria. In addition, DNA sequencing and sequence analyses indicated neither evolutionary selection pressure on the gene nor association of mutations in gene with mutations of other three genes conferring resistance to CQ and SP. Therefore, based on the monomorphism at the gene and nonassociation of mutations of this gene with mutations in three other drug-resistant genes in malaria parasite , it can be proposed that malaria public health is not under immediate threat in southwestern Nigeria concerning ART resistance.