Evidence map›Paper›PMID 40814090›Full record

ArticleMalaria journal2025

Measuring growth, resistance, and recovery after artemisinin treatment of Plasmodium falciparum in a single semi-high-throughput assay.

Mackenzie A C Sievert, Tarrick Qahash, Puspendra P Singh, Douglas A Shoue, Lisa A Checkley, Katelyn Vendrely Brenneman, Zione Cassady, Sudhir Kumar, Xue Li, François H Nosten and 4 more

Abstract read
In one paragraph

Article in Malaria journal, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

3 citing papers in PubMed.

  1. Article
  2. Functional validation of thebioRxiv : the preprint server for biology · 2026
    Article
  3. Article
4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

14 authors.

Mackenzie A C Sievert *Dept. of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA.
Tarrick Qahash *Dept. of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA.
Puspendra P SinghDept. of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA.
Douglas A ShoueDept. of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA.
Lisa A CheckleyDept. of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA.
Katelyn Vendrely BrennemanDept. of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA.
Zione CassadyDept. of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA.
Sudhir KumarCenter for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, USA.
Xue LiTexas Biomedical Research Institute, San Antonio, TX, USA.
François H NostenShoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Mae Sot, Thailand.
Timothy J C AndersonTexas Biomedical Research Institute, San Antonio, TX, USA.
Ashley M VaughanCenter for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, USA.
Jeanne Romero-SeversonDept. of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA.
Michael T FerdigDept. of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA. ferdig.1@nd.edu.

Funding

Systems genetics of artemisinin resistanceP01AI127338 · NIAID · UNIVERSITY OF NOTRE DAME · PI Michael T Ferdig, Ashley M Vaughan · 2017 to 2026
$21.3M
MAPPING DRUG RESISTANCE GENES IN PLASMODIUM FALCIPARUMR01AI048071 · NIAID · TEXAS BIOMEDICAL RESEARCH INSTITUTE · PI Tim J Anderson · 2000 to 2026
$8.4M
Mapping Drug Resistance Genes in Plasmodium falciparumR37AI048071 · NIAID · TEXAS BIOMEDICAL RESEARCH INSTITUTE · PI ANDERSON, TIM J · 2012 to 2021
$7.9M
NIAID NIH HHS P01 AI127338NIAID NIH HHS R01 AI048071NIAID NIH HHS R37 AI048071NIH HHS P01 AI127338NIH HHS R37 AI048071Wellcome Trust
6 · The paper itself

Abstract

backgroundArtemisinin partial resistance (ART-R) has spread throughout Southeast Asia and mutations in Pfkelch13, the molecular marker of resistance, are widely reported in East Africa. Effective in vitro assays and robust phenotypes are crucial for monitoring populations for the emergence and spread of resistance. The recently developed extended Recovery Ring-stage Survival Assay used a qPCR-based readout to reduce the labour intensiveness for in vitro phenotyping of ART-R and improved correlation with the clinical phenotype of ART-R. Here, the assay is extended and refined to include measurements of parasite growth and recovery after drug exposure. Clinical isolates and progeny from two genetic crosses were used to optimize and validate the reliability of a straight-from-blood, SYBR Green-based qPCR protocol in a 96-well plate format to accurately measure phenotypes with this new Growth, Resistance, and Recovery assay (GRRA).

resultsThe assay determined growth between 6 and 96 h, resistance at 120 h, and recovery from 120 to 192 h. Growth can be accurately captured by qPCR and is shown by reproduction of previous growth phenotypes from HB3 × Dd2. Resistance measured at 120 h continually shows the most consistent phenotype for ring stage susceptibility. Recovery identifies an additional response to drug in parasites that are determined sensitive by replicative viability at 120 h. Comparison of progeny phenotypes for Growth versus Resistance showed a minor but significant correlation, whereas Growth versus Recovery and Resistance versus Recovery showed no significant correlation. Additionally, dried blood spot (DBS) samples matched replicative viability measured from liquid samples demonstrating Resistance can be easily quantified using either storage method.

conclusionsThe direct-from-blood qPCR-based methodology provides the throughput needed to quickly measure large numbers of parasites for multiple relevant phenotypes. Growth can reveal fitness defects and illuminate relationships between proliferation rates and drug response. Recovery serves as a complementary phenotype to resistance that quantifies the ability of sensitive parasites to tolerate drug exposure. All three phenotypes offer a comprehensive assessment of parasite-drug interaction each with potential independent genetic determinants of main effect and overlapping secondary effects. By adapting the method to include DBS, readouts can be easily extended to ex vivo surveillance applications.

Indexed as

AntimalarialsArtemisininsDrug ResistanceHigh-Throughput Screening AssaysPlasmodium falciparumHumansParasitic Sensitivity TestsReal-Time Polymerase Chain ReactionAntimalarialsartemisininArtemisininsArtemisinin resistanceGenetic crossKelch13PhenotypesPlasmodium falciparumRing-stage survival assay

Identifiers

PMID40814090
PMCPMC12355871

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.