evaluation of dihydrofolate reductase (dhfr) gene, related to plasmodium falciparum pyrimethamine resistance in imported malaria cases in iran

Background: antimalarial drug resistance is one of the important challenges forgovernments in the fight against malaria. molecular surveillance of antimalarial drugresistance supports early detection of how the recommended treatments work. this allowsimmediate action to reduce any threat and prevent it from spreading. therefore, the aimof this study was to evaluate the frequency of dihydrofolate reductase (dhfr) mutants inplasmodium falciparum resistance to pyrimethamine in iranian malaria patients.materials and methods: in 2020, 27 patients (21 males and 5 females) with imported p.falciparum cases were studied. the nested-pcr technique first confirmed the species in allsamples and then amplification was done by the semi-nested-pcr method in order to detectsingle nucleotide polymorphisms (snps) in dhfr gene related to pyrimethamine resistance.results: all samples in the 18s rrna gene had species-specific bands for p. falciparumstrains. in the sequence analysis of pfdhfr gene amplification after comparison with thestandard strain (wild type), 21 patients had a double mutation (c59r+s108n) and sixpatients had a triple mutation (n51i+c59r+s108n) of pyrimethamine resistance.conclusion: the results of this study showed that the susceptibility of p. falciparum topyrimethamine in the treatment of malaria is significantly reducing. these findings canraise concerns about pyrimethamine resistance in p. falciparum. due to the high emergenceof double and triple mutants related to pyrimethamine resistance, the malaria surveillanceand treatment systems in iran, the use of pyrimethamine should be considered.