Development of nucleic acid aptamers against Plasmodium falciparum lactate dehydrogenase for improving the diagnosis of malaria

Abstract

Prompt confirmation of malaria infection by microscopy and/or rapid diagnostic tests (RDT) is critical to prevent the evolution of drug resistant Plasmodia strains, and also for effective use of artemesin-based combination therapies (ACT). However, malaria diagnosis remains a significant challenge as many malaria endemic regions have inadequate access to microscopy, and antibody-based RDTs are restricted by their poor stability under sustained tropical temperatures and by their cost. The development of nucleic acid aptamers against diagnostic markers for malaria may improve on conventional diagnostic approaches. In this study, DNA aptamers against the diagnostic marker, Plasmodium falciparum lactate dehydrogenase (PfLDH), were identified by Systematic Evolution of Ligands by Exponential Enrichment (SELEX). These DNA aptamers were observed to bind with nanomolar affinity and were highly specific to the Plasmodium LDH and did not bind to the human LDH. This work lays the foundation for further development of rapid diagnostic tests based on novel nucleic acid aptamers for robust and cost-effective malaria diagnosis.