Limited Polymorphism in Plasmodium falciparum Artemisinin Resistance Kelch13-Propeller Gene Among Clinical Isolates from Bushenyi District, Uganda

Maniga, Josephat Nyabayo; Akinola, Saheed Adekunle; Odoki, Martin; Odda, John; Adebayo, Ismail Abiola

doi:10.2147/idr.s341357

Cited by 4 publications

(4 citation statements)

References 36 publications

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“…Our study found a 24% microscopy positivity for P. falciparum on day three, which could indicate a possible emergence of partial artemisinin resistance (35,36). A similar finding on the persistence of P. falciparum has been reported previously in AL-treated malaria patients in Uganda (30,37–39). Whether this is attributed to the development of resistance, especially the K13 mutation, or lack of adherence to AL has not been fully established.…”

Section: Discussionsupporting

confidence: 90%

Day 3 parasitemia andPlasmodium falciparum Kelch 13mutations among uncomplicated malaria patients treated with artemether-lumefantrine in Adjumani district, Uganda

Angwe,

Mwebaza,

Nsobya

et al. 2024

Preprint

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Artemisinin resistance threatens malaria control and elimination efforts globally. Recent studies have reported the emergence of Plasmodium falciparum parasites tolerant to artemisinin agents in sub-Saharan Africa, including Uganda. The current study assessed the day 3 parasite clearance and its correlation with P. falciparum K13 propeller gene (pfkelch13) mutations in P. falciparum parasites isolated from patients with uncomplicated malaria under artemether-lumefantrine (AL) treatment. This study enrolled 100 P. falciparum-positive patients to whom AL was prescribed between 09/September/2022 and 06/November/2022. Blood samples were collected in EDTA tubes before treatment initiation (day 0) and on day 3. Parasitemia was assessed by microscopy from blood smears and quantitative polymerase chain reaction (qPCR) from the DNA extracted. The day 0 parasite K13 gene was sequenced using Sanger sequencing. Sequence data were analysed using MEGA version 11 software. The data were analysed using STATA version 15, and the Mann‒Whitney U test was used to compare PCR parasite clearance on day 3 using the comparative CT value method and pfkelch13 mutations. The prevalence of day 3 parasitaemia was 24% (24/100) by microscopy and 63% (63/100) by qPCR from the AL-treated patients. P. falciparum K13-propeller gene polymorphism was detected in 18.8% (15/80) of the day 0 DNA samples. The K13 mutations found were C469Y, 12.5% (10/80); A675V, 2.5% (2/80); A569S, 1.25%, (1/80), A578S, 1.25%, (1/80) and; F491S, 1.25%, (1/80) a new allele not reported anywhere. The C469Y mutation, compared to the wild-type, was associated with delayed parasite clearance p=0.0278, Hodges-Lehmann estimation 3.2108 on the log scale, (95%CI 1.7076, 4.4730). There was a high prevalence of day 3 P. falciparum among malaria patients treated using artemether-lumefantrine. We conclude that the K13 mutation associated with artemisinin resistance by P. falciparum is present in Adjumani district, Uganda. This necessitates regular surveillance of the effectiveness and efficacy of artemether-lumefantrine in the country.

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Section: Discussionsupporting

confidence: 90%

Day 3 parasitemia andPlasmodium falciparum Kelch 13mutations among uncomplicated malaria patients treated with artemether-lumefantrine in Adjumani district, Uganda

Angwe,

Mwebaza,

Nsobya

et al. 2024

Preprint

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“…Therefore, Further research and exploration into the specific mechanisms by which immunity may impact the dynamics of antimalarial drug response, especially in the context of delayed clearance, would provide valuable insights into the complexity of malaria resistance and treatment outcomes. The findings from the present study, which indicate a lack of mutation in the pfk13 propeller domain and limited polymorphism seen in [21] combined with observations from other studies in Kenya and Africa [25,26,27,28] revealing the majority of non-synonymous mutations which are not associated with delayed parasite clearance, collectively suggest that K13 may not be the most reliable predictive molecular marker for artemisinin resistance in Africa. These results emphasize the need for continued research to identify alternative molecular markers or factors that can better predict and understand the dynamics of artemisinin resistance in the African context.…”

Section: Discussioncontrasting

confidence: 57%

Slow parasite clearance, absent K13 gene polymorphisms and observation of amino-acids silent mutations among malaria non-responsive patients: A case study of Kisii County, Kenya.

BWOGO,

Mong’are,

Masai

et al. 2024

Preprint

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Malaria poses a substantial global health challenge, with the majority of instances concentrated in countries within Sub-Saharan Africa. A variety of antimalarial medications have been created to address the widespread occurrence of Plasmodium falciparum malaria. Since 2004, Artemisinin-based Combination Therapy (ACT) has been the primary treatment for uncomplicated malaria in Kenya. Nevertheless, there is a rising concern attributable to the increasing reports of ACT resistance, particularly in Southeast Asia, and its extension into Africa. In particular, mutations in the Kelch propeller domain on chromosome 13 (Pfk13) have been associated with resistance to ACT. However, our comprehension of mutation prevalence in Africa remains mostly unexplored, especially as slow parasite clearance becomes increasingly prevalent. In this study, we assess polymorphisms in the Plasmodium falciparum Kelch13 propeller gene among malaria non-responsive patients who attended selected hospitals in endemic regions of Kisii County, Kenya. The research found out that all participants experiencing delayed parasite clearance had low parasitemia levels (< 500) after completing the full dose of the ACT drug, as opposed to their parasitemia levels before taking the ACT drugs. The parasite density for all participants in the study who experienced delayed parasite clearance on the first day before taking the ACT drug showed a high mean ± SE of 13951.9 ± 3564.72. In contrast, during the third-day visit, the mean was notably lower at 327.90 ± 41.11, coinciding with their claim of not responding to the drug. Upon sequencing the K13-propeller gene of the isolates and conducting a search for synonymous and non-synonymous mutations in the propeller region of K13, no polymorphism was observed. Surprisingly, upon further investigation into the amino acids of the isolated samples, silent mutations were observed. Continued global surveillance of artemisinin resistance remains crucial, and our findings offer insights into the possible dissemination of resistant parasites in East Africa. These findings suggest that the detection of silent mutations particularly those associated with delayed parasite clearance following ACT, may imply a gradual emergence of ACT-resistant parasites. This warrants additional investigation through in-vitro assays to determine the functional significance of these findings.

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“…Other studies either reported lower prevalence or detected no PfK13 mutations in Ugandan parasite isolates [15][16][17][18][19][20][21]. Among the PfK13 mutations reported in previous studies in Uganda, the C469Y, A675V and P574L are both classified by the WHO as validated markers of partial artemisinin resistance.…”

Section: Introductionmentioning

confidence: 95%

Emerging threat of Partial Artemisinin Resistance Markers in P. falciparum Parasite Populations in multiple geographical locations in high Transmission Regions of Uganda

Agaba,

Travis,

Smith

et al. 2024

Preprint

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Background: Artemisinin-based combination therapies (ACTs) is the only recommended treatment option for uncomplicated malaria, however the emergency and spread of partial artemisinin resistance threatens their effectiveness for malaria treatment in sub-Saharan Africa where the burden of malaria is highest. Early detection and reporting of validated P. falciparum Kelch 13 (PfK13) mutation markers is useful for tracking the emergence and spread of artemisinin resistance to inform containment. Methods: Genomic surveillance was conducted at 50 sites across four regions of Uganda in Karamoja, Lango, Acholi and West Nile from June 2021 to August 2023 for assessing prevalence of pfhrp2/3 deletions and pfk13 mutations. Symptomatic malaria suspected patients were recruited and screened for presence of parasites. Out of 563 available dried blood spots (DBS), a random subset of 240 P. falciparum mono-infections, confirmed by a conventional multiplex PCR, were selected and used for detecting mutations in the propeller region of the pfk13 gene by Sanger sequencing using Big Dye Terminator method. Regional variations in the proportions of PfK13 mutations were assessed using the chi square or Fisher’s exact tests while Kruskal-Wallis test was used to compare absolute parasite DNA levels between wild type and mutants parasites. Results: Overall, 238/240 samples (99.2%) contained sufficient DNA and were successfully sequenced. Three mutations were identified within the sequenced samples; PfK13 C469Y in 32/238 (13.5%) samples, PfK13 A675V in 14/238 (5.9%) and PfK13 S522C in (1/238 (0.42%) samples across the four surveyed regions. The prevalence of PfK13 C469Y mutation was significantly higher in Karamoja region (23.3%) compared to other regions, P=0.007. Majority of parasite isolates circulating in West Nile are of wild type (100%), P=0.002. Relative parasite DNA quantity did not differ in samples carrying the wild type, C469Y and A675V alleles (Kruskal-Wallis test, p=0.6373). Conclusion: The prevalence of validated markers of artemisinin resistance PfK13 A675V and PfK13 C469Y in multiple geographical locations in this high transmission setting provides additional evidence for the emerging threat of artemisinin resistance in Uganda. In view of these findings, country-specific artemisinin resistance management strategy should be developed including periodic genomic surveillance to detect and monitor levels of PfK13 mutations in other regions in parallel with in-vivo therapeutic efficacy studies (TES) to assess potential implication on delayed parasite clearance and associated treatment failure in this setting.

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Limited Polymorphism in Plasmodium falciparum Artemisinin Resistance Kelch13-Propeller Gene Among Clinical Isolates from Bushenyi District, Uganda

Cited by 4 publications

References 36 publications

Day 3 parasitemia andPlasmodium falciparum Kelch 13mutations among uncomplicated malaria patients treated with artemether-lumefantrine in Adjumani district, Uganda

Day 3 parasitemia andPlasmodium falciparum Kelch 13mutations among uncomplicated malaria patients treated with artemether-lumefantrine in Adjumani district, Uganda

Slow parasite clearance, absent K13 gene polymorphisms and observation of amino-acids silent mutations among malaria non-responsive patients: A case study of Kisii County, Kenya.

Emerging threat of Partial Artemisinin Resistance Markers in P. falciparum Parasite Populations in multiple geographical locations in high Transmission Regions of Uganda

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