Are k13 and plasmepsin II genes, involved in Plasmodium falciparum resistance to artemisinin derivatives and piperaquine in Southeast Asia, reliable to monitor resistance surveillance in Africa?

Abstract Background: Over the last decade, Artemisinin-based Combination Therapies (ACT) have contributed substantially to the decrease in malaria-related morbidity and mortality. The emergence of Plasmodium falciparum parasites resistant to artemisinin derivatives in Southeast Asia and the risk of their spread or of local emergence in sub-Saharan Africa are a major threat to public health. This study thus set out to estimate the proportion of P. falciparum isolates, with PfKelch13 gene mutations associated with artemisinin resistance previously detected in Southeast Asia. Methods: Blood samples were collected in two sites of Bangui, the capital of the Central African Republic form 2017 to 2019. DNA was extracted and nested PCR were carried out to detect Plasmodium species and mutations in the propeller domain of the PfKelch13 gene. Results: A total of 255 P. falciparum isolates were analyzed. Among them, P. ovale DNA was found in four samples (1.57%, 4/255). Of 187 samples with interpretable PfKelch13 sequences, four isolates presented a mutation in the PfKelch13 gene (2.1%, 4/187), including one non-synonymous mutation (Y653N) (0.5%, 1/187). This mutation has never been described as associated with artemisinin resistance in Southeast Asia and its in vitro phenotype is unknown. Conclusion: This preliminary study indicates the need for a larger study on samples collected across the whole country along with the evaluation of in vitro and in vivo phenotype profiles of PfKelch13 mutant parasites to estimate the risk of artemisinin resistance in the CAR.

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Molecular assessment of kelch13 non-synonymous mutations in Plasmodium falciparum isolates from Central African Republic (2017–2019)

10.21203/rs.2.24742/v1 ◽

2020 ◽

Author(s):

Romaric Nzoumbou-Boko ◽

Chris-Boris Gildas Panté-Wockama ◽

Carine Ngoagoni ◽

Nathalie Petiot ◽

Eric Legrand ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Southeast Asia ◽

Central African Republic ◽

Artemisinin Resistance ◽

Plasmodium Species ◽

Sub Saharan Africa ◽

Artemisinin Derivatives ◽

Synonymous Mutations

Abstract Background: Over the last decade, Artemisinin-based Combination Therapies (ACT) have contributed substantially to the decrease in malaria-related morbidity and mortality. The emergence of Plasmodium falciparum parasites resistant to artemisinin derivatives in Southeast Asia and the risk of their spread or of local emergence in sub-Saharan Africa are a major threat to public health. This study thus set out to estimate the proportion of P. falciparum isolates, with PfKelch13 gene mutations associated with artemisinin resistance previously detected in Southeast Asia. Methods: Blood samples were collected in two sites of Bangui, the capital of the Central African Republic form 2017 to 2019. DNA was extracted and nested PCR were carried out to detect Plasmodium species and mutations in the propeller domain of the PfKelch13 gene. Results: A total of 255 P. falciparum isolates were analyzed. Among them, P. ovale DNA was found in four samples (1.57%, 4/255). Of 187 samples with interpretable PfKelch13 sequences, four isolates presented a mutation in the PfKelch13 gene (2.1%, 4/187), including one non-synonymous mutation (Y653N) (0.5%, 1/187). This mutation has never been described as associated with artemisinin resistance in Southeast Asia and its in vitro phenotype is unknown. Conclusion: This preliminary study indicates the need for a larger study on samples collected across the whole country along with the evaluation of in vitro and in vivo phenotype profiles of PfKelch13 mutant parasites to estimate the risk of artemisinin resistance in the CAR.

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Emergence and Spread of kelch13 Mutations Associated with Artemisinin Resistance in Plasmodium falciparum Parasites in 12 Thai Provinces from 2007 to 2016

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02141-17 ◽

2018 ◽

Vol 62 (4) ◽

Cited By ~ 10

Author(s):

Theerayot Kobasa ◽

Eldin Talundzic ◽

Rungniran Sug-aram ◽

Patcharida Boondat ◽

Ira F. Goldman ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Gene Mutations ◽

Artemisinin Resistance ◽

Parasite Clearance ◽

Resistance Mutations ◽

Content Type ◽

Artemisinin Derivatives ◽

Reduced Ring ◽

Control And Prevention ◽

Greater Mekong Subregion

ABSTRACT Artemisinin-based combination therapy (ACT) is the most effective and widely used treatment for uncomplicated Plasmodium falciparum malaria and is a cornerstone for malaria control and prevention globally. Resistance to artemisinin derivatives has been confirmed in the Greater Mekong Subregion (GMS) and manifests as slow parasite clearance in patients and reduced ring stage susceptibility to artemisinins in survival assays. The P. falciparum kelch13 gene mutations associated with artemisinin-resistant parasites are now widespread in the GMS. We genotyped 277 samples collected during an observational study from 2012 to 2016 from eight provinces in Thailand to identify P. falciparum kelch13 mutations. The results were combined with previously reported genotyping results from Thailand to construct a map illustrating the evolution of P. falciparum kelch13 mutations from 2007 to 2016 in that country. Different mutant alleles were found in strains with different geographical origins. The artemisinin resistance-conferring Y493H and R539T mutations were detected mainly in eastern Thailand (bordering Cambodia), while P574L was found only in western Thailand and R561H only in northwestern Thailand. The C580Y mutation was found across the entire country and was nearing fixation along the Thai-Cambodia border. Overall, the prevalence of artemisinin resistance mutations increased over the last 10 years across Thailand, especially along the Thai-Cambodia border. Molecular surveillance and therapeutic efficacy monitoring should be intensified in the region to further assess the extent and spread of artemisinin resistance.

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In Vitro Antimalarial Evaluation of Piperidine- and Piperazine-Based Chalcones: Inhibition of Falcipain-2 and Plasmepsin II Hemoglobinases Activities from Plasmodium falciparum

ChemistrySelect ◽

10.1002/slct.201701162 ◽

2017 ◽

Vol 2 (25) ◽

pp. 7684-7690 ◽

Cited By ~ 5

Author(s):

Hemandra Kumar Tiwari ◽

Prashant Kumar ◽

Nidhi Jatana ◽

Krishan Kumar ◽

Sandeep Garg ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Plasmepsin Ii

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Efficacy of dihydroartemisinin/piperaquine in patients with non-complicated Plasmodium falciparum malaria in Yaoundé, Cameroon

Journal of Antimicrobial Chemotherapy ◽

10.1093/jac/dkab281 ◽

2021 ◽

Author(s):

Mélissa Mairet-Khedim ◽

Sandrine Nsango ◽

Christelle Ngou ◽

Sandie Menard ◽

Camille Roesch ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Southeast Asia ◽

Falciparum Malaria ◽

Gene Polymorphisms ◽

Plasmodium Falciparum Malaria ◽

Molecular Profile ◽

Uncomplicated Plasmodium Falciparum Malaria ◽

In Vitro Survival ◽

Phenotypic Susceptibility

Abstract Background Dihydroartemisinin/piperaquine is increasingly used for the treatment of uncomplicated Plasmodium falciparum malaria in Africa. The efficacy of this combination in Cameroon is poorly documented, while resistance to dihydroartemisinin/piperaquine readily spreads in Southeast Asia. Objectives This study evaluated the clinical efficacy of dihydroartemisinin/piperaquine in Cameroon, as well as the molecular profile and phenotypic susceptibility of collected isolates to dihydroartemisinin and piperaquine. Patients and methods Dihydroartemisinin/piperaquine efficacy in 42 days was followed-up for 138 patients presenting non-complicated falciparum malaria. Piperaquine concentration was determined at day 7 for 124 patients. kelch13 gene polymorphisms (n = 150) and plasmepsin2 gene amplification (n = 148) were determined as molecular markers of resistance to dihydroartemisinin and piperaquine, respectively. Parasite susceptibility to dihydroartemisinin and piperaquine was determined using validated in vitro survival assays. Results The efficacy of dihydroartemisinin/piperaquine treatment was 100% after PCR correction. The reinfections were not associated with a variation of piperaquine concentration at day 7. Ninety-six percent (144/150) of the samples presented a WT allele of the kelch13 gene. Two percent (3/150) presented the non-synonymous mutation A578S, which is not associated with resistance to dihydroartemisinin. No duplication of the plasmepsin2 gene was observed (0/148). All the samples tested in vitro by survival assays (n = 87) were susceptible to dihydroartemisinin and piperaquine. Conclusions Dihydroartemisinin/piperaquine has demonstrated excellent therapeutic efficacy with no evidence of emerging artemisinin or piperaquine resistance in Yaoundé, Cameroon. This observation suggests that dihydroartemisinin/piperaquine could be a sustainable therapeutic solution for P. falciparum malaria if implemented in areas previously free of artemisinin- and piperaquine-resistant parasites, unlike Southeast Asia.

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Expansion of a Specific Plasmodium falciparum PfMDR1 Haplotype in Southeast Asia with Increased Substrate Transport

mBio ◽

10.1128/mbio.02093-20 ◽

2020 ◽

Vol 11 (6) ◽

Author(s):

Carla Calçada ◽

Miguel Silva ◽

Vitória Baptista ◽

Vandana Thathy ◽

Rita Silva-Pedrosa ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Multidrug Resistance ◽

Southeast Asia ◽

Gene Copy ◽

Multidrug Resistance Protein ◽

Combination Therapies ◽

Transport Capacity ◽

Multidrug Resistance Protein 1 ◽

Content Type ◽

Resistance Protein

ABSTRACT Artemisinin-based combination therapies (ACTs) have been vital in reducing malaria mortality rates since the 2000s. Their efficacy, however, is threatened by the emergence and spread of artemisinin resistance in Southeast Asia. The Plasmodium falciparum multidrug resistance protein 1 (PfMDR1) transporter plays a central role in parasite resistance to ACT partner drugs through gene copy number variations (CNV) and/or single nucleotide polymorphisms (SNPs). Using genomic epidemiology, we show that multiple pfmdr1 copies encoding the N86 and 184F haplotype are prevalent across Southeast Asia. Applying genome editing tools on the Southeast Asian Dd2 strain and using a surrogate assay to measure transporter activity in infected red blood cells, we demonstrate that parasites harboring multicopy N86/184F PfMDR1 have a higher Fluo-4 transport capacity compared with those expressing the wild-type N86/Y184 haplotype. Multicopy N86/184F PfMDR1 is also associated with decreased parasite susceptibility to lumefantrine. These findings provide evidence of the geographic selection and expansion of specific multicopy PfMDR1 haplotypes associated with multidrug resistance in Southeast Asia. IMPORTANCE Global efforts to eliminate malaria depend on the continued success of artemisinin-based combination therapies (ACTs) that target Plasmodium asexual blood-stage parasites. Resistance to ACTs, however, has emerged, creating the need to define the underlying mechanisms. Mutations in the P. falciparum multidrug resistance protein 1 (PfMDR1) transporter constitute an important determinant of resistance. Applying gene editing tools combined with an analysis of a public database containing thousands of parasite genomes, we show geographic selection and expansion of a pfmdr1 gene amplification encoding the N86/184F haplotype in Southeast Asia. Parasites expressing this PfMDR1 variant possess a higher transport capacity that modulates their responses to antimalarials. These data could help tailor and optimize antimalarial drug usage in different regions where malaria is endemic by taking into account the regional prevalence of pfmdr1 polymorphisms.

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Artemisone and Artemiside Are Potent Panreactive Antimalarial Agents That Also Synergize Redox Imbalance in Plasmodium falciparum Transmissible Gametocyte Stages

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02214-17 ◽

2018 ◽

Vol 62 (8) ◽

Cited By ~ 8

Author(s):

Dina Coertzen ◽

Janette Reader ◽

Mariëtte van der Watt ◽

Sindisiwe H. Nondaba ◽

Liezl Gibhard ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Malaria Control ◽

Malaria Parasite ◽

Redox Homeostasis ◽

New Drugs ◽

Content Type ◽

Artemisinin Derivatives ◽

Antimalarial Agents ◽

Redox Partner ◽

Emergence Of Resistance

ABSTRACT The emergence of resistance toward artemisinin combination therapies (ACTs) by the malaria parasite Plasmodium falciparum has the potential to severely compromise malaria control. Therefore, the development of new artemisinins in combination with new drugs that impart activities toward both intraerythrocytic proliferative asexual and transmissible gametocyte stages, in particular, those of resistant parasites, is urgently required. We define artemisinins as oxidant drugs through their ability to oxidize reduced flavin cofactors of flavin disulfide reductases critical for maintaining redox homeostasis in the malaria parasite. Here we compare the activities of 10-amino artemisinin derivatives toward the asexual and gametocyte stages of P. falciparum parasites. Of these, artemisone and artemiside inhibited asexual and gametocyte stages, particularly stage V gametocytes, in the low-nanomolar range. Further, treatment of both early and late gametocyte stages with artemisone or artemiside combined with the pro-oxidant redox partner methylene blue displayed notable synergism. These data suggest that modulation of redox homeostasis is likely an important druggable process, particularly in gametocytes, and this finding thereby enhances the prospect of using combinations of oxidant and redox drugs for malaria control.

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Distinctive Origin and Spread Route of Pyrimethamine-Resistant Plasmodium falciparum in Southern China

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00972-13 ◽

2013 ◽

Vol 58 (1) ◽

pp. 237-246 ◽

Cited By ~ 5

Author(s):

Yilong Zhang ◽

He Yan ◽

Guiying Wei ◽

Shitong Han ◽

Yufu Huang ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Southeast Asia ◽

Southern China ◽

Hainan Island ◽

Epidemiological Studies ◽

Single Nucleotide ◽

Evolutionary Pathway ◽

Content Type ◽

Genetic Linkages ◽

High Level

ABSTRACTSoutheast Asia (the Thailand-Cambodia border) has been considered the primal epicenter for most antimalarial drug resistance; however, numerous molecular epidemiological studies have successively reported multiple independent origins of sulfadoxine-pyrimethamine (SP) resistance-associatedPlasmodium falciparumdhfr(pfdhfr) andpfdhpsalleles in other areas. To better understand the origin and evolutionary pathway of the SP resistance in Southeast Asia, a total of 374P. falciparumfield isolates from the Yunnan-Burma border and Hainan Island in southern China have been collected for comprehensive investigations on the mutation patterns of thepfdhfr/pfdhpsgenes as well as their microsatellite haplotypes. By comparative analysis of single-nucleotide polymorphism (SNP) genotyping and flanking microsatellite haplotypes, we reveal a unique origin of pyrimethamine-resistant mutations inPfdhfrgene in Hainan Island and an oriented spread route of the pyrimethamine resistance from the Thailand-Cambodia border into the Hainan area, which reflects the geographical traits and SP administration histories in the two geographically independent areas. Moreover, genetic linkages between the high-level SP resistance-conferringpfdhfr/pfdhpsalleles have been established in the isolates from the Yunnan-Burma border, raising the concern of a genetic basis in adopting combination chemotherapies against falciparum malaria.

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