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A novel field-based molecular assay to detect validated artemisinin-resistant <italic>k13</italic> mutants.

Authors :
Vachot-Ganée, Laurence
Khim, Nimol
Iannello, Alexandra
Legrand, Eric
Kim, Saorin
Eam, Rotha
Khean, Chanra
Ken, Malen
Ashley, Elizabeth
Tun, Kyaw Myo
Dhorda, Mehul
Nosten, François
Souleymane, Issa Mahamat
Blein, Sophie
Pachot, Alexandre
Ariey, Frédéric
Kaiser, Karine
Ménard, Didier
Source :
Malaria Journal; 4/24/2018, Vol. 17 Issue 1, pN.PAG-N.PAG, 1p, 5 Charts, 3 Graphs
Publication Year :
2018

Abstract

Background: Given the risk of artemisinin resistance spreading from the Greater Mekong sub-region, prospective monitoring in sub-Saharan Africa should be expedited. Molecular biology techniques used for monitoring rely on the detection of &lt;italic&gt;k13&lt;/italic&gt; validated mutants by using PCR and Sanger sequencing approach, usually not available in malaria endemic areas. Methods: A semi-automated workflow based on the easyMAG&lt;superscript&gt;&#174;&lt;/superscript&gt; platform and the Argene Solution&lt;superscript&gt;&#174;&lt;/superscript&gt; (bioM&#233;rieux, Marcy l&#39;Etoile, France) as a field-based surveillance tool operable at national level was developed in four steps. Clinical and analytical performances of this tool detecting five of the most frequent and validated &lt;italic&gt;k13&lt;/italic&gt; mutants (Y493H, I543T, R539T, F446I and C580Y) from dried blood spots (DBS) were compared to the gold standard approach (PCR and Sanger sequencing). Results: By using the ARMS (amplification-refractory mutation system) strategy, the best multiplexing options were found in 3 separate real-time PCR duplexes (IC as internal control/I543T, C580Y/Y493H and F446I/R539T) with limits of detection ranging from 50 (C580Y) to 6.25 parasites/&#181;L (Y493H). In field conditions, using 642 clinical DBS (from symptomatic patients and asymptomatic individuals) collected from Cambodia, Myanmar and Africa (Chad), the overall sensitivity and specificity of the K13 bMx prototype assay developed by bioM&#233;rieux were ≥ 90%. Areas under the ROC curves were estimated to be &gt; 0.90 for all &lt;italic&gt;k13&lt;/italic&gt; mutants in samples from symptomatic patients. Conclusion: The K13 ready-to-use bMx prototype assay, considered by the end-users as a user-friendly assay to perform (in shorter time than the K13 reference assay) and easy to interpret, was found to require less budget planning and had fewer logistical constraints. Its excellent performance qualifies the prototype as a reliable screening tool usable in malaria endemic countries recognized to be at risk of emergence or spread of validated &lt;italic&gt;k13&lt;/italic&gt; mutants. Additional multi-site studies are needed to evaluate the performances of the K13 bMx prototype assay in different epidemiological contexts such as Africa, India, or South America. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
14752875
Volume :
17
Issue :
1
Database :
Complementary Index
Journal :
Malaria Journal
Publication Type :
Academic Journal
Accession number :
129271440