Genetic Insights into Plasmodium falciparum Resistance to Sulfadoxine-pyrimethamine through a Study of the 540-dihydropteroate Synthetase Gene Mutations in Jos, Nigeria

Aim: This study investigates mutations at codon 540 in the dihydropteroate synthetase (540dhps) gene that may confer resistance to sulfadoxine-pyrimethamine treatment by Plasmodium falciparum in Jos.

Study Design: The research employs a cross-sectional study design.

Place and Duration of Study: Samples were collected in Jos, Plateau State, Nigeria, from October 2019 to January 2021.

Methodology: One hundred malaria cases underwent assessment, and parasite DNA was extracted from whole blood samples using Zymo extraction kits. PCR and gel electrophoresis identified the Plasmodium genus and P. falciparum, along with the 540dhps gene. Sanger sequencing and bioinformatics analyses were performed.

Results: About 50% of the collected samples were positive for the Plasmodium genus, with P. falciparum in 96% of cases. About 16% of P. falciparum samples were successfully amplified for the 540dhps gene. A silent point mutation was discovered at position 10 of the nucleotide sequence of the 540dhps gene which did not result in amino acid changes.

Conclusion: The study highlights the predominant presence of Plasmodium falciparum in Jos, with a substantial 96% prevalence among malaria patients. Unlike the previously reported mutations at codon K540E on the 540dhps gene from other studies, the observed mutation on the nucleotide sequence did not affect the amino acid sequence. Thus, the observed mutation may not be associated with resistance to sulfadoxine-pyrimethamine drugs.