Genetic Profiling of Plasmodium falciparum Antigenic Biomarkers among Asymptomatic Pregnant Women on Intermittent Preventive Treatment with Sulfadoxine-Pyrimethamine from Southwest Nigeria

Abstract

Abstract Background The genetic complexity of Plasmodium falciparum is a contributory factor to the emergence of drug-resistant parasites. The WHO recommends intermittent preventive treatment of malaria in pregnancy with sulfadoxine-pyrimethamine (IPTp-SP) in malaria endemic settings. This study evaluated the prevalence of the Plasmodium falciparum multidrug resistance-1 gene (mdr-1), genetic diversity of merozoite surface proteins (msp-1, msp-2) and glutamate-rich protein (glurp) among pregnant women from southwest Nigeria. Methods One hundred PCR-confirmed Plasmodium falciparum isolates, comprising visit 1 (V1) (n = 52), delivery (n = 31) and cord blood (n = 17), were randomly selected for analysis. The mdr-1 haplotypes were evaluated using restriction fragment length polymorphism (RLFP), while the msp-1, msp-2 and glurp genes were genotyped using nested PCR. Allelic frequencies, proportions and multiplicity of infection were calculated, and the p value was considered ≤ 0.05. Results The mdr-1 (N86/N86Y) combination was detected in 11.8% (V1), 61.3% (delivery) and 58.8% (cord blood) from the isolates (p ≤ 0.05). The mutant (N86Y) haplotype was detected only in cord isolates (5.9%). The allelic frequency distribution for msp-1 was 245 (K1 = 81, MAD20 = 85 and RO33 = 79), and that for msp-2 was 110, representing 43.6% (FC27) and 56.4% (3D7), respectively. While glurp expressed the least allelic frequency of 25, 84% (V1), 12% (delivery) and 4% (cord), respectively (p ≤ 0.05). msp-1 and msp-2 recorded higher MOIs than glurp. Conclusion Antigenic falciparum strains with N86Y Pfmdr-1, msp-1, msp-2, and glurp may compromise the effectiveness of IPTp-SP in southwest Nigeria. The search for newer drug formulations for IPTp may be needed.