Real-time PCR detection of mixed < i > Plasmodium ovale curtisi < /i > and < i > wallikeri < /i > infections in human and mosquito hosts

by Varun R. Potlapalli, Meredith S. Muller, Billy Ngasala, Innocent Mbulli Ali, Yu Bin Na, Danielle R. Williams, Oksana Kharabora, Srijana Chhetri, Mei S. Liu, Kelly Carey-Ewend, Feng-Chang Lin, Derrick Mathias, Brian B. Tarimo, Jonathan J. Juliano, Jonathan B. Parr, Jessica T. LinPlasmodium ovale curtisi (Poc) andPlasmodium ovale wallikeri (Pow) represent distinct non-recombiningPlasmodium species that are increasing in prevalence in sub-Saharan Africa. Though they circulate sympatrically, co-infection within human and mosquito hosts has rarely been described. Separate 18S rRNA real-time PCR assays that detectPoc andPow were modified to allow species determination in parallel under identical cycling conditions. The lower limit of detection was 0.6 plasmid copies/ μL (95% CI 0.4–1.6) forPoc and 4.5 plasmid copies/μL (95% CI 2.7 –18) forPow, or 0.1 and 0.8 parasites/ μL, respectively, assuming 6 copies of 18s rRNA per genome. However, the assays showed cross-reactivity at concentrations greater than 103 plasmid copies/ μL (roughly 200 parasites/μL). Mock mixtures were used to establish criteria for classifying mixedPoc/Pow infections that prevented false-positive detection while maintaining sensitive detection of the minority ovale species down to 100 copies/ μL (
Source: PLoS Neglected Tropical Diseases - Category: Tropical Medicine Authors: Source Type: research