Genetic polymorphism of the thrombospondin-related apical merozoite protein (TRAMP) of Plasmodium knowlesi in Malaysia

Plasmodium knowlesi is a simian malaria parasite that causes significant zoonotic infections in Southeast Asia, particularly in Malaysia. The Plasmodium thrombospondin-related apical merozoite protein (TRAMP) plays an essential role in the invasion of the parasite into its host erythrocyte. The present study investigated the genetic polymorphism and natural selection of the full length PkTRAMP from P. knowlesi clinical isolates from Malaysia. Blood samples (n=40) were collected from P. knowlesi malaria patients from Peninsular Malaysia and Malaysian Borneo. The PkTRAMP gene was amplified using PCR, followed by cloning into a plasmid vector and sequenced. Results showed that the nucleotide diversity of PkTRAMP was low (pi: 0.009). Z-test results indicated negative (purifying) selection of PkTRAMP. The alignment of the deduced amino acid sequences of PkTRAMP of Peninsular Malaysia and Malaysian Borneo revealed 38 dimorphic sites. A total of 27 haplotypes were identified from the amino acid sequence alignment. Haplotype analysis revealed that there was no clustering of PkTRAMP from Peninsular Malaysia and Malaysian Borneo.

Automated summary

This study investigated the genetic polymorphism and natural selection of PkTRAMP from P. knowlesi clinical isolates in Malaysia. The nucleotide diversity of PkTRAMP was found to be low, indicating negative selection. Analysis of the amino acid sequences revealed 38 dimorphic sites and 27 haplotypes, with no clustering observed between samples from Peninsular Malaysia and Malaysian Borneo.