dna sequence polymorphism of the lactate dehydrogenase gene¬from iranian plasmodium vivax and plasmodium falcipa¬rum isolates

background: parasite lactate dehydrogenase ( p ldh) is extensively employed as malaria rapid diagnostic tests (rdts). moreover, it is a well-known drug target candidate. however, the genetic diversity of this gene might influence perfor­mance of rdt kits and its drug target candidacy. this study aimed to determine polymorphism of p ldh gene from iranian isolates of p. vivax and p. falciparum. methods: genomic dna was extracted from whole blood of microscopically confirmed p. vivax and p. falciparum infected patients. p ldh gene of p. falciparum and p. vivax was amplified using conventional pcr from 43 symptomatic malaria patients from sistan and baluchistan province, southeast iran from 2012 to 2013 . results: sequence analysis of 15 p. vivax ldh showed fourteen had 100% identity with p. vivax sal-1 and belem strains. two nucleotide substitutions were detected with only one resulted in amino acid change. analysis of p. falciparum ldh sequences showed six of the seven sequences had 100% homology with p. falciparum 3d7 and mzr-1. moreover, pf ldh displayed three nucleotide changes that resulted in changing only one amino acid. pv ldh and pf ldh showed 75%-76% nucleotide and 90.4%-90.76% amino acid homology. conclusion: p ldh gene from iranian p. falciparum and p. vivax isolates displayed 98.8-100% homology with 1-3 nucleotide substitutions. this indicated this gene was relatively conserved. additional studies can be done weather this genetic variation can influence the performance of p ldh based rdts or not.