Real-time PCR detection of mixed Plasmodium ovale curtisi and wallikeri infections in human and mosquito hosts.
Plasmodium ovale curtisi (Poc) and Plasmodium ovale wallikeri (Pow) represent distinct non-recombining Plasmodium 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...
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ftdoajarticles:oai:doaj.org/article:21e27b4171524e07bfd3e53cd491ce12 2024-02-04T09:58:37+01:00 Real-time PCR detection of mixed Plasmodium ovale curtisi and wallikeri infections in human and mosquito hosts. 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 Lin 2023-12-01T00:00:00Z https://doi.org/10.1371/journal.pntd.0011274 https://doaj.org/article/21e27b4171524e07bfd3e53cd491ce12 EN eng Public Library of Science (PLoS) https://doi.org/10.1371/journal.pntd.0011274 https://doaj.org/toc/1935-2727 https://doaj.org/toc/1935-2735 1935-2727 1935-2735 doi:10.1371/journal.pntd.0011274 https://doaj.org/article/21e27b4171524e07bfd3e53cd491ce12 PLoS Neglected Tropical Diseases, Vol 17, Iss 12, p e0011274 (2023) Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 article 2023 ftdoajarticles https://doi.org/10.1371/journal.pntd.0011274 2024-01-07T01:41:23Z Plasmodium ovale curtisi (Poc) and Plasmodium ovale wallikeri (Pow) represent distinct non-recombining Plasmodium 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 detect Poc and Pow 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) for Poc and 4.5 plasmid copies/μL (95% CI 2.7-18) for Pow, 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 mixed Poc/Pow infections that prevented false-positive detection while maintaining sensitive detection of the minority ovale species down to 100 copies/μL (<1 parasite/μL). When the modified real-time PCR assays were applied to field-collected blood samples from Tanzania and Cameroon, species identification by real-time PCR was concordant with nested PCR in 19 samples, but additionally detected two mixed Poc/Pow infections where nested PCR detected a single Po species. When real-time PCR was applied to oocyst-positive Anopheles midguts saved from mosquitoes fed on P. ovale-infected persons, mixed Poc/Pow infections were detected in 11/14 (79%). Based on these results, 8/9 P. ovale carriers transmitted both P. ovale species to mosquitoes, though both Po species could only be detected in the blood of two carriers. The described real-time PCR approach can be used to identify the natural occurrence of mixed Poc/Pow infections in human and mosquito hosts and reveals that such co-infections and co-transmission are likely more common than appreciated. Article in Journal/Newspaper Arctic Directory of Open Access Journals: DOAJ Articles Arctic PLOS Neglected Tropical Diseases 17 12 e0011274 |
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Open Polar |
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Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 |
spellingShingle |
Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 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 Lin Real-time PCR detection of mixed Plasmodium ovale curtisi and wallikeri infections in human and mosquito hosts. |
topic_facet |
Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 |
description |
Plasmodium ovale curtisi (Poc) and Plasmodium ovale wallikeri (Pow) represent distinct non-recombining Plasmodium 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 detect Poc and Pow 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) for Poc and 4.5 plasmid copies/μL (95% CI 2.7-18) for Pow, 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 mixed Poc/Pow infections that prevented false-positive detection while maintaining sensitive detection of the minority ovale species down to 100 copies/μL (<1 parasite/μL). When the modified real-time PCR assays were applied to field-collected blood samples from Tanzania and Cameroon, species identification by real-time PCR was concordant with nested PCR in 19 samples, but additionally detected two mixed Poc/Pow infections where nested PCR detected a single Po species. When real-time PCR was applied to oocyst-positive Anopheles midguts saved from mosquitoes fed on P. ovale-infected persons, mixed Poc/Pow infections were detected in 11/14 (79%). Based on these results, 8/9 P. ovale carriers transmitted both P. ovale species to mosquitoes, though both Po species could only be detected in the blood of two carriers. The described real-time PCR approach can be used to identify the natural occurrence of mixed Poc/Pow infections in human and mosquito hosts and reveals that such co-infections and co-transmission are likely more common than appreciated. |
format |
Article in Journal/Newspaper |
author |
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 Lin |
author_facet |
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 Lin |
author_sort |
Varun R Potlapalli |
title |
Real-time PCR detection of mixed Plasmodium ovale curtisi and wallikeri infections in human and mosquito hosts. |
title_short |
Real-time PCR detection of mixed Plasmodium ovale curtisi and wallikeri infections in human and mosquito hosts. |
title_full |
Real-time PCR detection of mixed Plasmodium ovale curtisi and wallikeri infections in human and mosquito hosts. |
title_fullStr |
Real-time PCR detection of mixed Plasmodium ovale curtisi and wallikeri infections in human and mosquito hosts. |
title_full_unstemmed |
Real-time PCR detection of mixed Plasmodium ovale curtisi and wallikeri infections in human and mosquito hosts. |
title_sort |
real-time pcr detection of mixed plasmodium ovale curtisi and wallikeri infections in human and mosquito hosts. |
publisher |
Public Library of Science (PLoS) |
publishDate |
2023 |
url |
https://doi.org/10.1371/journal.pntd.0011274 https://doaj.org/article/21e27b4171524e07bfd3e53cd491ce12 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
PLoS Neglected Tropical Diseases, Vol 17, Iss 12, p e0011274 (2023) |
op_relation |
https://doi.org/10.1371/journal.pntd.0011274 https://doaj.org/toc/1935-2727 https://doaj.org/toc/1935-2735 1935-2727 1935-2735 doi:10.1371/journal.pntd.0011274 https://doaj.org/article/21e27b4171524e07bfd3e53cd491ce12 |
op_doi |
https://doi.org/10.1371/journal.pntd.0011274 |
container_title |
PLOS Neglected Tropical Diseases |
container_volume |
17 |
container_issue |
12 |
container_start_page |
e0011274 |
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1789963072749699072 |