Variant Plasmodium ovale isolated from a patient infected in Ghana

Abstract

Recent data have found that Plasmodium ovale can be separated in two distinct species: classic and variant P. ovale based on multilocus typing of different genes. This study presents a P. ovale isolate from a patient infected in Ghana together with an analysis of the small subunit RNA, cytochrome b, cytochrome c oxidase I, cysteine protease and lactate dehydrogenase genes, which show that the sample is a variant P. ovale and identical or highly similar to variant P. ovale isolated from humans in South-East Asia and Africa, and from a chimpanzee in Cameroon. The split between the variant and classic P. ovale is estimated to have occurred 1.7 million years ago.

Recent Advances in Detection of Plasmodium ovale: Implications of Separation into the Two Species Plasmodium ovale wallikeri and Plasmodium ovale curtisi

“…They reported a divergence of 12 bp in a 1,035-bp partial sequence. These results have been confirmed by several studies, one of which analyzed and compared 357-bp partial cytb sequences of P. ovale, clearly discriminating two mitochondrial cytb genotypes (3,11,14,15).…”

“…Dimorphisms have also been observed in genes encoding cytochrome c oxidase 1 (cox1; at least 12 loci); lactate dehydrogenase (ldh), ookinete surface antigens, P. ovale reticulate binding protein 2 (porbp2), P. ovale glyceraldehyde-3-phosphatase (pog3p), P. ovale dihydrofolate reductase-thymidylate synthase (podhfr-ts), P. ovale cysteine proteinase (pocysp), and P. ovale tryptophan-rich antigen (potra) (3,5,6,11,12,13,14,16,17).…”

“…The nuclear small subunit (SSU) rRNA genes are known to be highly conserved regions suitable not only for phylogenetic studies but also for the molecular detection of human malaria parasites (3,5,6,11,12,13). The copy numbers of this gene range from 4 to 8.…”

Prevalence of Plasmodium falciparum and non-P. falciparum infections in a highland district in Ghana, and the influence of HIV and sickle cell disease

“…Both P. ovale curtisi and P. ovale wallikeri have been found to circulate in the population in Ashanti region [10]; whilst P. ovale wallikeri was diagnosed in a foreign visitor to the country who visited different regions in the country [32]. Even though the occurrence of falciparum malaria was slightly lower than the Ghana national prevalence of 90–98% [4], P. malariae in this study was much higher at 12.7% compared to that of the national prevalence of 2–9% [4].…”

Malaria Diagnostics and Surveillance in the Post-Genomic Era

“…Current RDTs capture products such as the histidine-rich protein -2 (Pf HRP-2), which is P. falciparum -specific, or the aldolase and lactate dehydrogenase enzyme (LDH) which are genus-specific and are therefore capable of detecting all Plasmodia , but are not able to discriminate species. However, highly divergent species such as P. ovale can produce negative RDT results due to sequence variation [12]. In addition, the lack of the hrp-2 gene in some P. falciparum parasites in parts of South America and Africa [13,14] has raised some concerns about HRP-2-based RDT use due to the potential for false negative results.…”