Molecular Characterisation of Plasmodium falciparum Drug Resistance Markers in Clinical Isolates from Enugu State, South East Nigeria

Antimalarial drug resistance driven by genetic mutations in Plasmodium falciparum continues to undermine malaria treatment efficacy in sub-Saharan Africa, necessitating ongoing molecular surveillance of resistance markers to preserve the clinical utility of artemisinin-based combination therapies. This study performs molecular characterisation of P. falciparum drug resistance markers in clinical isolates from Enugu State, South East Nigeria. A cross-sectional analytical design was employed, recruiting 250 malaria-positive patients from tertiary and secondary health facilities in Enugu, Awgu, and Oji-River Local Government Areas. Dried blood spots were collected on filter paper and transported to a molecular laboratory for DNA extraction using the Chelex method. Polymerase chain reaction and restriction fragment length polymorphism analyses were used to genotype mutations in the Pfkelch13, Pfdhfr, and Pfdhps genes associated with artemisinin, pyrimethamine, and sulfadoxine resistance respectively. Microsatellite genotyping was performed to assess parasite population structure. Evidence from 2020 to 2024 confirms the emergence of Pfkelch13 non-synonymous mutations in West African P. falciparum populations, raising concerns about emerging partial artemisinin resistance. This study fills a surveillance gap by providing state-level resistance marker data from southeastern Nigeria, informing national antimalarial policy review. Findings will be submitted to the National Malaria Elimination Programme and published in a peer-reviewed parasitology journal. Keywords: Plasmodium falciparum, drug resistance markers, molecular characterisation, Enugu State, artemisinin.