Amplification of LDH gene from indian strains of Plasmodium vivax.

ABSTRACT

BACKGROUND & OBJECTIVES: Plasmodium vivax is geographically widespread and responsible for > 50% of malaria cases in India. Increased drug resistance of the parasite highlights the immediate requirement of early and accurate diagnosis as well as new therapeutics. In view of this, the present study was undertaken to amplify P. vivax (Indian strains) lactate dehydrogenase gene (PvLDH) which has been identified as a good target for antimalarials as well as diagnostics. METHODS: P. vivax infected clinical blood samples were collected from southern part of India and were tested with established diagnostic parameters (ICT, Giemsa staining). Total DNA was extracted from blood samples and subjected to PCR using two sets of primers, one for the amplification of full PvLDH gene (951 bp) and the other for a partial PvLDH gene fragment (422bp), covering a variable antigenic region (140aa) as compared to other plasmodial species. RESULTS & CONCLUSION: PCRs for both the full and partial gene targets were optimised and found to be consistent when tested on several P. vivax positive clinical samples. In addition, full gene PCR was found to specifically detect only P. vivax DNA and could be used as a specific molecular diagnostic tool. These amplified products can be cloned and expressed as a recombinant protein that might be useful for the development and screening of antimalarials as well as for diagnostic purposes.