重庆市输入性卵形疟原虫curtisi和wallikeri亚种分子特征分析OA北大核心CSTPCD

This study was aimed at understanding the molecular characteristics of Plasmodium ovale curtisi and Plasmodi-um ovale wallikeri imported cases in Chongqing,to provide data to support monitoring and control efforts.In a retrospective analysis,26 Plasmodium ovale archival blood samples were characterized with respect to five molecular markers(Cox1,Cytb,Tra,Dhfr,and K13)from 2013 to 2023.PCR amplification of partial fragments of the Cox1,Cytb,and Tra genes of Plas-modium ovale was performed to distinguish the two subspecies.The drug-resistance Dhfr and K13 genes of Plasmodium ovale were amplified with PCR assays followed by DNA sequencing,and the sequences were aligned.The differentiation of 26 cases of Plasmodium ovale(14 cases of curtisi subspecies and 12 cases of wallikeri subspecies)according to ssrRNA was consistent with the classification results of Cox1,Cytb,and TRA genes.Thirteen single nucleotide dimorphism sites were identified in Cox 1,including the 145 and 153 loci,with only variations in amino acids M176I and I288V at loci 528 and 862,and N337H mutation in one sample.Twelve base substitutions were found among Cytb gene subspecies,with only the M248I mutation in amino acid 248.A total of 49 nucleotide dimorphism sites in Tra gene,resulting in 18 amino acid mutations,were identified be-tween the two subspecies.In the curtisi type sample,the poc1 type had more PINTINPINTIN and TITPIS amino acid units than the poc2 type.The mutation rate of the Dhfr gene was rel-atively high:25％of the samples showed S58R mutations.The K13 gene subspecies was not homozygous,and one sample was heterozygous.This study confirmed the dimorphism and mutation sites between Plasmodium ovale curtisi and wallikeri sub-species in Cox1,Cytb,Tra,Dhfr,and K13 gene fragments of imported Plasmodium ovale in Chongqing,thus enriching knowledge regarding gene polymorphisms in Plasmodium ovale curtisi and wallikeri imported cases.