The molecular characteristics of circumsporozoite protein gene subtypes from Plasmodium vivax isolates in Republic of Korea.

The circumsporozoite protein (CSP) of Plasmodium vivax has two sequence types, VK210 and VK247, each of which has a characteristic tandem amino acid repetition. Previous studies report that a resurgent Korean strain has unique amino acid sequences in tandem repeats and post-repeat areas compared to other strains of P. vivax. We have found another molecular subtype of the CSP gene from resurgent Korea isolates. New strains show a total of eighteen amino acid repeats and different amino acid repeat patterns compared with previous resurgent Korean isolates. In the post-repeat region, AGGNAANKKAEDAGGNA and three repeats of the sequence GGNA was found in all six isolates. These results of sequence comparison revealed that there are two types of isolates based on CSP in South Korea.