11 results on '"Ndounga, Mathieu"'
Search Results
2. Plasmodium falciparum K13 mutations in Africa and Asia impact artemisinin resistance and parasite fitness
- Author
-
Stokes, Barbara H, primary, Dhingra, Satish K, additional, Rubiano, Kelly, additional, Mok, Sachel, additional, Straimer, Judith, additional, Gnädig, Nina F, additional, Deni, Ioanna, additional, Schindler, Kyra A, additional, Bath, Jade R, additional, Ward, Kurt E, additional, Striepen, Josefine, additional, Yeo, Tomas, additional, Ross, Leila S, additional, Legrand, Eric, additional, Ariey, Frédéric, additional, Cunningham, Clark H, additional, Souleymane, Issa M, additional, Gansané, Adama, additional, Nzoumbou-Boko, Romaric, additional, Ndayikunda, Claudette, additional, Kabanywanyi, Abdunoor M, additional, Uwimana, Aline, additional, Smith, Samuel J, additional, Kolley, Olimatou, additional, Ndounga, Mathieu, additional, Warsame, Marian, additional, Leang, Rithea, additional, Nosten, François, additional, Anderson, Timothy JC, additional, Rosenthal, Philip J, additional, Ménard, Didier, additional, and Fidock, David A, additional
- Published
- 2021
- Full Text
- View/download PDF
3. Author response: Plasmodium falciparum K13 mutations in Africa and Asia impact artemisinin resistance and parasite fitness
- Author
-
Stokes, Barbara H, primary, Dhingra, Satish K, additional, Rubiano, Kelly, additional, Mok, Sachel, additional, Straimer, Judith, additional, Gnädig, Nina F, additional, Deni, Ioanna, additional, Schindler, Kyra A, additional, Bath, Jade R, additional, Ward, Kurt E, additional, Striepen, Josefine, additional, Yeo, Tomas, additional, Ross, Leila S, additional, Legrand, Eric, additional, Ariey, Frédéric, additional, Cunningham, Clark H, additional, Souleymane, Issa M, additional, Gansané, Adama, additional, Nzoumbou-Boko, Romaric, additional, Ndayikunda, Claudette, additional, Kabanywanyi, Abdunoor M, additional, Uwimana, Aline, additional, Smith, Samuel J, additional, Kolley, Olimatou, additional, Ndounga, Mathieu, additional, Warsame, Marian, additional, Leang, Rithea, additional, Nosten, François, additional, Anderson, Timothy JC, additional, Rosenthal, Philip J, additional, Ménard, Didier, additional, and Fidock, David A, additional
- Published
- 2021
- Full Text
- View/download PDF
4. P. falciparum K13 mutations present varying degrees of artemisinin resistance and reduced fitness in African parasites
- Author
-
Stokes, Barbara H., primary, Rubiano, Kelly, additional, Dhingra, Satish K., additional, Mok, Sachel, additional, Straimer, Judith, additional, Gnädig, Nina F., additional, Bath, Jade R., additional, Deni, Ioanna, additional, Ward, Kurt E., additional, Striepen, Josefine, additional, Yeo, Tomas, additional, Ross, Leila S., additional, Legrand, Eric, additional, Ariey, Frédéric, additional, Cunningham, Clark H., additional, Souleymane, Issa M., additional, Gansané, Adama, additional, Nzoumbou-Boko, Romaric, additional, Ndayikunda, Claudette, additional, Kabanywanyi, Abdunoor M., additional, Uwimana, Aline, additional, Smith, Samuel J., additional, Kolley, Olimatou, additional, Ndounga, Mathieu, additional, Warsame, Marian, additional, Leang, Rithea, additional, Nosten, François, additional, Anderson, Timothy J.C., additional, Rosenthal, Philip J., additional, Ménard, Didier, additional, and Fidock, David A., additional
- Published
- 2021
- Full Text
- View/download PDF
5. Plasmodium falciparum K13 mutations in Africa and Asia present varying degrees of artemisinin resistance and an elevated fitness cost in African parasites
- Author
-
Stokes, Barbara H., primary, Rubiano, Kelly, additional, Dhingra, Satish K., additional, Mok, Sachel, additional, Straimer, Judith, additional, Gnädig, Nina F., additional, Bath, Jade R., additional, Deni, Ioanna, additional, Ward, Kurt E., additional, Striepen, Josefine, additional, Yeo, Tomas, additional, Ross, Leila S., additional, Legrand, Eric, additional, Ariey, Frédéric, additional, Cunningham, Clark H., additional, Souleymane, Issa M., additional, Gansané, Adama, additional, Nzoumbou-Boko, Romaric, additional, Ndayikunda, Claudette, additional, Kabanywanyi, Abdunoor M., additional, Uwimana, Aline, additional, Smith, Samuel J., additional, Kolley, Olimatou, additional, Ndounga, Mathieu, additional, Warsame, Marian, additional, Leang, Rithea, additional, Nosten, François, additional, Anderson, Timothy J.C., additional, Rosenthal, Philip J., additional, Ménard, Didier, additional, and Fidock, David A., additional
- Published
- 2021
- Full Text
- View/download PDF
6. Beyond genome-wide scan: Association of a cis-regulatory NCR3 variant with mild malaria in a population living in the Republic of Congo
- Author
-
Baaklini, Sabrina, Afridi, Sarwat, Nguyen, Thy Ngoc, Koukouikila-Koussounda, Felix, Ndounga, Mathieu, Imbert, Jean, Torres, Magali, Pradel, Lydie, Ntoumi, Francine, Rihet, Pascal, Technologies avancées pour le génôme et la clinique (TAGC), Aix Marseille Université (AMU)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Université Marien Ngouabi, Centre d’Etudes sur les Ressources Végétales, Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM), and Rihet, Pascal
- Subjects
Male ,Cytotoxicity ,lcsh:Medicine ,Gene Expression ,Artificial Gene Amplification and Extension ,NK cells ,Toxicology ,Pathology and Laboratory Medicine ,Biochemistry ,Polymerase Chain Reaction ,[SDV.MHEP.MI]Life Sciences [q-bio]/Human health and pathology/Infectious diseases ,Cellular types ,Medicine and Health Sciences ,Malaria, Falciparum ,lcsh:Science ,Promoter Regions, Genetic ,Protozoans ,Immune cells ,Malarial Parasites ,Eukaryota ,STAT4 Transcription Factor ,Enzymes ,Congo ,[SDV.MHEP.MI] Life Sciences [q-bio]/Human health and pathology/Infectious diseases ,White blood cells ,Female ,Oxidoreductases ,Luciferase ,Research Article ,Cell biology ,Blood cells ,Immunology ,[SDV.GEN.GH] Life Sciences [q-bio]/Genetics/Human genetics ,Research and Analysis Methods ,Polymorphism, Single Nucleotide ,parasitic diseases ,DNA-binding proteins ,Parasitic Diseases ,Genetics ,Humans ,Genetic Predisposition to Disease ,Gene Regulation ,Molecular Biology Techniques ,Molecular Biology ,Alleles ,Binding Sites ,Natural Cytotoxicity Triggering Receptor 3 ,Biology and life sciences ,lcsh:R ,Organisms ,Proteins ,Tropical Diseases ,Parasitic Protozoans ,Malaria ,Regulatory Proteins ,Core Binding Factor Alpha 3 Subunit ,HEK293 Cells ,[SDV.GEN.GH]Life Sciences [q-bio]/Genetics/Human genetics ,Animal cells ,Genetic Loci ,Enzymology ,lcsh:Q ,K562 Cells ,Transcription Factors - Abstract
International audience; Linkage studies have revealed a linkage of mild malaria to chromosome 6p21 that contains the NCR3 gene encoding a natural killer cell receptor, whereas NCR3-412G>C (rs2736191) located in its promoter region was found to be associated with malaria in Burkina Faso. Here we confirmed the association of rs2736191 with mild malaria in a Congolese cohort and investigated its potential cis-regulatory effect. Luciferase assay results indicated that rs2736191-G allele had a significantly increased promoter activity compared to rs2736191-C allele. Furthermore, EMSAs demonstrated an altered binding of two nuclear protein complexes to the rs2736191-C allele in comparison to rs2736191-G allele. Finally, after in silico identification of transcription factor candidates, pull-down western blot experiments confirmed that both STAT4 and RUNX3 bind the region encompassing rs2736191 with a higher affinity for the G allele. To our knowledge, this is the first report that explored the functional role of rs2736191. These results support the hypothesis that genetic variation within natural killer cell receptors alters malaria resistance in humans.
- Published
- 2017
7. Little Polymorphism at the K13 Propeller Locus in Worldwide Plasmodium falciparum Populations Prior to the Introduction of Artemisinin Combination Therapies
- Author
-
Mita, Toshihiro, primary, Culleton, Richard, additional, Takahashi, Nobuyuki, additional, Nakamura, Masatoshi, additional, Tsukahara, Takahiro, additional, Hunja, Carol W., additional, Win, Zin Zayar, additional, Htike, Wah Win, additional, Marma, Aung S., additional, Dysoley, Lek, additional, Ndounga, Mathieu, additional, Dzodzomenyo, Mawuli, additional, Akhwale, Willis S., additional, Kobayashi, Jun, additional, Uemura, Haruki, additional, Kaneko, Akira, additional, Hombhanje, Francis, additional, Ferreira, Marcelo U., additional, Björkman, Anders, additional, Endo, Hiroyoshi, additional, and Ohashi, Jun, additional
- Published
- 2016
- Full Text
- View/download PDF
8. Malaria burden and anti-malarial drug efficacy in Owando, northern Congo
- Author
-
Singana, Brice P., primary, Bogreau, Hervé, additional, Matondo, Brunelle D., additional, Dossou-Yovo, Louis R., additional, Casimiro, Prisca N., additional, Mbouka, Rigobert, additional, Ha Nguyen, Kim Yen, additional, Pradines, Bruno, additional, Basco, Leonardo K., additional, and Ndounga, Mathieu, additional
- Published
- 2016
- Full Text
- View/download PDF
9. Artesunate-amodiaquine versus artemether-lumefantrine for the treatment of acute uncomplicated malaria in Congolese children under 10 years old living in a suburban area: a randomized study.
- Author
-
Ndounga, Mathieu, Issamou Mayengue, Pembe, Casimiro, Prisca Nadine, Koukouikila-Koussounda, Félix, Bitemo, Michel, Diassivy Matondo, Brunelle, Ndounga Diakou, Lee Aymar, Basco, Leonardo K., and Ntoumi, Francine
- Subjects
- *
MALARIA treatment , *AMODIAQUINE , *JUVENILE diseases , *ARTEMISININ , *MALARIA prevention , *GOVERNMENT policy - Abstract
Background: The Republic of Congo adopted a new anti-malarial treatment policy in 2006, with artesunate-amodiaquine (ASAQ) and artemether-lumefantrine (AL) as the first- and second-line anti-malarial drugs, respectively. Only three clinical studies had been conducted before the policy change. A randomized study on these two artemisininbased combinations was conducted, and the effect that sickle cell trait may have on treatment outcomes was evaluated in children under 10 years old followed during 12 months in Brazzaville in 2010–2011. Methods: A cohort of 330 children under 10 years of age living in a suburban area in the south of Brazzaville were passively followed for registration of malaria episodes. Uncomplicated Plasmodium falciparum episodes were randomly treated with co-formulated ASAQ (Coarsucam®) or AL (Coartem®). Patients were followed according to the 2009 World Health Organization protocol for the evaluation of anti-malarial drug efficacy. Plasmodium falciparum recrudescent isolates were compared to pre-treatment isolates by polymerase chain reaction (PCR) to distinguish between re-infection and recrudescence. PCR-uncorrected and PCR-corrected responses to treatment were determined using per protocol analysis. Haemoglobin type (AA, AS, SS) was determined by PCR. Results: Of 282 clinical malaria episodes registered during 1-year follow-up period, 262 children with uncomplicated malaria were treated with ASAQ (129 patients) or AL (133 patients). The PCR-corrected efficacy, expressed as the percentage of adequate clinical and parasitological response, was 97.0 % for ASAQ and 96.4 % for AL. Among ASAQtreated patients, 112 (86.8 %) carried AA genotype and 17 (13.2 %) were AS carriers. The PCR-corrected efficacy was 96.4 % for AA-carriers and 100 % for AS-carriers treated with ASAQ [relative risk (RR) = 0.96; 95 % confidence interval, 0.93–1.00, p = 0.5]. Among 133 AL-treated children, 109 (82 %) carried AA, and 24 (18 %) AS genotypes. The PCR-corrected efficacy was 96.7 % among AA-carriers and 95.2 % among AS-carriers [RR = 1.01 (0.92–1.12), p = 0.6]. Nausea, jaundice, headache, dizziness, vomiting, pruritus, abdominal pain, and diarrhoea were registered as adverse events in both groups. ASAQ was associated with significantly more frequent adverse events (P < 0.05). Conclusion: This first randomized study in Brazzaville confirmed the excellent efficacy of these co-formulated antimalarial drugs in children. Sickle cell genotype did not influence the treatment efficacy of artemisinin-based combination therapy. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
10. Little Polymorphism at the K13 Propeller Locus in Worldwide Plasmodium falciparumPopulations Prior to the Introduction of Artemisinin Combination Therapies
- Author
-
Mita, Toshihiro, Culleton, Richard, Takahashi, Nobuyuki, Nakamura, Masatoshi, Tsukahara, Takahiro, Hunja, Carol W., Win, Zin Zayar, Htike, Wah Win, Marma, Aung S., Dysoley, Lek, Ndounga, Mathieu, Dzodzomenyo, Mawuli, Akhwale, Willis S., Kobayashi, Jun, Uemura, Haruki, Kaneko, Akira, Hombhanje, Francis, Ferreira, Marcelo U., Björkman, Anders, Endo, Hiroyoshi, and Ohashi, Jun
- Abstract
ABSTRACTThe emergence and spread of artemisinin-resistant Plasmodium falciparumis of huge concern for the global effort toward malaria control and elimination. Artemisinin resistance, defined as a delayed time to parasite clearance following administration of artemisinin, is associated with mutations in the Pfkelch13gene of resistant parasites. To date, as many as 60 nonsynonymous mutations have been identified in this gene, but whether these mutations have been selected by artemisinin usage or merely reflect natural polymorphism independent of selection is currently unknown. To clarify this, we sequenced the Pfkelch13propeller domain in 581 isolates collected before (420 isolates) and after (161 isolates) the implementation of artemisinin combination therapies (ACTs), from various regions of endemicity worldwide. Nonsynonymous mutations were observed in 1% of parasites isolated prior to the introduction of ACTs. Frequencies of mutant isolates, nucleotide diversity, and haplotype diversity were significantly higher in the parasites isolated from populations exposed to artemisinin than in those from populations that had not been exposed to the drug. In the artemisinin-exposed population, a significant excess of dN compared to dS was observed, suggesting the presence of positive selection. In contrast, pairwise comparison of dN and dS and the McDonald and Kreitman test indicate that purifying selection acts on the Pfkelch13propeller domain in populations not exposed to ACTs. These population genetic analyses reveal a low baseline of Pfkelch13polymorphism, probably due to purifying selection in the absence of artemisinin selection. In contrast, various Pfkelch13mutations have been selected under artemisinin pressure.
- Published
- 2016
- Full Text
- View/download PDF
11. Genetic diversity of Plasmodium falciparum infection among children with uncomplicated malaria living in Pointe-Noire, Republic of Congo.
- Author
-
Singana, Brice Pembet, Mayengue, Pembe Issamou, Niama, Roch Fabien, and Ndounga, Mathieu
- Subjects
- *
PLASMODIUM falciparum , *MALARIA , *PLASMODIUM , *NATURAL immunity , *INFECTION - Abstract
Introduction: Molecular characterization of malaria parasites from different localities is important to improve understanding of acquisition of natural immunity to Plasmodium falciparum, to assist in identifying the most appropriate strategies for control and to evaluate the impact of control interventions. This study aimed to determine the genetic diversity and the multiplicity of infection in Plasmodium falciparum isolates from Pointe- Noire, Republic of Congo. Methods: Plasmodium falciparum isolates were collected from 71 children with uncomplicated malaria; enrolled into the study for evaluating the therapeutic efficacy of artemether-lumefantrine combination. Both msp-1 and msp-2 genes were genotyped. Results: From 296 distinct fragments detected, 13 msp-1 and 27 msp-2 different alleles were identified. For msp-1, RO33 family was poorly polymorphic. The K1 family has shown the trend of predominance (41%), followed by Mad20 (35%). Comparatively to msp-2, 49.6% and 48.8% fragments belonged to 3D7 and FC27 respectively. Taking together msp-1 and msp-2 genes, the overall multiplicity of infection has been increased to 2.64 and 86% harbored more than one parasite genotype. Parasite density was not influenced by age as well as the multiplicity of infection which was not influenced neither by age nor by parasite density. Conclusion: Genetic diversity of Plasmodium falciparum in isolates from patients with uncomplicated malaria in Pointe-Noire is high and consisted mainly of multiple clones. The overall multiplicity of infection has been largely increased when considering msp-1 and msp-2 genes together. With the changes in malaria epidemiology, the use of both msp-1 and msp-2 genes in the characterization of Plasmodium falciparum infection is recommended. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.