Abstract:

To develop a PCR-based detection of Plasmodium ovale infection, DNA was extracted from blood of a patient diagnosed as the first imported case of P. ovale infection in Guizhou province, two sets of PCR based on the Plasmodium ribosomal RNA small subunit (SSU rRNA) and mitochondrial cytochrome oxidase subunit 3 gene(cox3) were established. The genus, species-specific primers were designed accordingly, the specificity of Plasmodium species detection was performed using the designed primers and the amplified cox3 PCR products were sequenced. The obtained sequences were aligned with reference sequence of the P. ovale wallikeri subspecies(GenBank accession number: HQ712053.1)and the curtisi subspecies(GenBank accession number: HQ712052.1)using DNAMAN V6. A phylogenetic tree was constructed based on the Plasmodium cox3 gene using the neighbor-joining method and Mega 7.0.26 software. The PCR results showed that only a genus-specific band with 1 200 bp was obtained based on Plasmodium SSU rRNA and no species-specific bands were amplified. However, a PCR product with 880 bp was amplified from the patient sample based on Plasmodium cox3 gene. The Blast alignment showed that the obtained cox3 sequence shared 99.4% identity with P. ovale wallikeri subspecies and 97.4% with curtisi subspecies.

Key words: Imported ovale malaria, wallikeri, PCR identification