Genetic diversity of Plasmodium falciparum isolates from Pahang, Malaysia based on MSP-1 and MSP-2 genes

Seventy-five P. falciparum isolates were genotyped by using nested-PCR of MSP-1 (block 2) and MSP-2 (block 3).MSP-1 and MSP-2 allelic families were identified in 65 blood samples. RO33 was the predominant MSP-1 allelic family identified in 80.0% (52/65) of the samples while K1 family had the least frequency. Of the MSP-2 allelic families, 3D7 showed higher frequency (76.0%) compared to FC27 (20.0%). The multiplicity of P. falciparum infection (MOI) was 1.37 and 1.20 for MSP-1 and MSP-2, respectively. A total of seven alleles were detected; of which three MSP-1 allelic families (RO33, MAD20 and K1) were monomorphic in terms of size while MSP-2 alleles were polymorphic (two 3D7 and two FC27). Heterozygosity (HE) was 0.57 and 0.55 for MSP-1 and MSP-2, respectively.The study showed that the MOI of P. falciparum is low, reflected the low intensity of malaria transmission in Pahang, Malaysia; RO33 and 3D7 were the most predominant circulating allelic families. The findings showed that P. falciparum has low allelic diversity with a high frequency of alleles. As a result, antimalarial drug efficacy trials based on MSP genotyping should be carefully interpreted.Malaria has been a global health problem threatening more than 40% of the world's population, and about 300-500 million cases of malaria infection are reported every year with approximately one million deaths, mostly among children and pregnant women [1]. Among the malarial parasites, Plasmodium falciparum, causes the most severe malarial attacks, is responsible for the high morbidity and mortality, frequent antimalarial drug resistance and aborted vaccines trials [2,3].Genetic diversity determines the intensity of malaria transmission, thus providing baseline data for any antimalarial drug efficacy trial and the possibility of implementing control strategies based on vaccines. Merozoite surface proteins 1 and 2 (MSP-1 and MSP-2) are widely used to study the allelic diversity and frequency of P. falciparum which are m