Genomic miscellany and allelic frequencies of Plasmodium falciparum msp-1, msp-2 and glurp in parasite isolates

Abstract

Introduction The genomic miscellany of malaria parasites can help inform the intensity of malaria transmission and identify potential deficiencies in malaria control programs. This study was aimed at investigating the genomic miscellany, allele frequencies, and MOI of P. falciparum infection. Methods A total of 85 P. falciparum confirmed isolates out of 100 were included in this study that were collected from P. falciparum patients aged 4 months to 60 years in nine districts of Khyber Pakhtunkhwa Province. Parasite DNA was extracted from 200µL whole blood samples using the Qiagen DNA extraction kit following the manufacturer’s instructions. The polymorphic regions of msp-1, msp-2 and glurp loci were genotyped using nested PCR followed by gel electrophoresis for amplified fragments identification and subsequent data analysis. Results Out of 85 P. falciparum infections detected, 30 were msp-1 and 32 were msp-2 alleles specific. Successful amplification occurred in 88.23% (75/85) isolates for msp-1, 78.9% (67/85) for msp-2 and 70% (60/85) for glurp gene. In msp-1, the K1 allelic family was predominantly prevalent as 66.66% (50/75), followed by RO33 and MAD20. The frequency of samples with single infection having only K1, MAD20 and RO33 were 21.34% (16/75), 8% (6/75), and 10.67% (8/75), respectively. In msp-2, both the FC27 and 3D7 allelic families revealed almost the same frequencies as 70.14% (47/67) and 67.16% (45/67), respectively. Nine glurp RII region alleles were identified in 60 isolates. The overall mean multiplicity of infection for msp genes was 1.6 with 1.8 for msp-1 and 1.4 for msp-2, while for glurp the MOI was 1.03. There was no significant association between multiplicity of infection and age groups (Spearman’s rank coefficient = 0.050; P = 0.6) while MOI and parasite density correlated for only msp-2 allelic marker. Conclusions The study showed high genetic diversity and allelic frequency with multiple clones of msp-1, msp-2 and glurp in P. falciparum isolates in Khyber Pakhtunkhwa, Pakistan. In the present study the genotype data may provide valuable information essential for monitoring the impact of malaria eradication efforts in this region.