1
|
Guémas E, Coppée R, Ménard S, du Manoir M, Nsango S, Makaba Mvumbi D, Nakoune E, Eboumbou Moukoko CE, Bouyou Akotet MK, Mirabeau TY, Manguin S, Malekita Yobi D, Akiana J, Kouna LC, Mawili Mboumba DP, Voumbo-Matoumona DF, Otam AL, Rubbo PA, Lombart JP, Kwanai E, Cohen O, Iriart X, Ayong L, Lekana-Douki JB, Ariey F, Berry A. Evolution and spread of Plasmodium falciparum mutations associated with resistance to sulfadoxine-pyrimethamine in central Africa: a cross-sectional study. Lancet Microbe 2023; 4:e983-e993. [PMID: 37865113 DOI: 10.1016/s2666-5247(23)00211-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 06/26/2023] [Accepted: 06/28/2023] [Indexed: 10/23/2023]
Abstract
BACKGROUND Efficacy of sulfadoxine-pyrimethamine, the malaria chemoprophylaxis used in pregnant women, and in children when combined with amodiaquine, is threatened by the accumulation of mutations in the Plasmodium falciparum dihydropteroate synthase (pfdhps) and dihydrofolate reductase (pfdhfr) genes. Data on the prevalence of resistant alleles in central Africa and the new pfdhps I431V mutation, particularly associated with other mutations to form the pfdhps vagKgs allele, are scarce. We explored the frequency and geographical distribution of pfdhps and pfdhfr mutations in central Africa in 2014-18, and assessed the evolutionary origin of the vagKgs allele. METHODS Samples were collected at 18 health-care centres in seven countries (Angola, Cameroon, Central African Republic, Democratic Republic of the Congo, Gabon, Nigeria, and Republic of the Congo) from patients who showed possible symptoms of malaria between March 1, 2014, and Oct 31, 2018. Samples that were positive for P falciparum were transported to a laboratory in Toulouse, France, and genotyped. The frequency of pfdhfr and pfdhps mutations was studied in 1749 samples. Microsatellites in pfdhps flanking regions and whole-genome analysis compared with parasite genomes from the data-sharing network MalariaGEN were performed on samples carrying the vagKgs allele. FINDINGS Mapping of the prevalence of single nucleotide polymorphisms and corresponding alleles of pfdhfr and pfdhps showed a substantial spread of alleles associated with sulfadoxine-pyrimethamine resistance in central Africa during the 2014-18 period, especially an increase going west to east in pfdhps alleles carrying the K540E and A581G mutations. A high prevalence of the pfdhps I431V mutation was observed in Cameroon (exceeding 50% in the northern region) and Nigeria. Genomic analysis showed a recent African emergence and a clonal expansion of the most frequent pfdhps vagKgs allele. INTERPRETATION Reduced sulfadoxine-pyrimethamine efficacy due to increased resistance is a worrying situation, especially because the malaria transmission level is high in central Africa. Although the resistance phenotype remains to be confirmed, the emergence and spread of the vagKgs allele in west and central Africa could challenge the use of sulfadoxine-pyrimethamine. FUNDING Toulouse Institute for Infectious and Inflammatory Diseases.
Collapse
Affiliation(s)
- Emilie Guémas
- Institut Toulousain des Maladies Infectieuses et Inflammatoires (Infinity), Université de Toulouse, CNRS UMR5051, INSERM UMR 1291, UPS, Toulouse, France; Département de Parasitologie et Mycologie, CHU Toulouse, Toulouse, France; LAAS-CNRS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Romain Coppée
- Université Paris Cité and Sorbonne Paris Nord, INSERM, IAME, Paris, France
| | - Sandie Ménard
- Institut Toulousain des Maladies Infectieuses et Inflammatoires (Infinity), Université de Toulouse, CNRS UMR5051, INSERM UMR 1291, UPS, Toulouse, France
| | - Milena du Manoir
- Institut Toulousain des Maladies Infectieuses et Inflammatoires (Infinity), Université de Toulouse, CNRS UMR5051, INSERM UMR 1291, UPS, Toulouse, France
| | - Sandrine Nsango
- Faculté de Médecine et des Sciences Pharmaceutiques, Université de Douala, Douala, Cameroon; Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroon
| | - Dieudonné Makaba Mvumbi
- Department of Basic Sciences, Faculty of Medicine, University of Kinshasa, Kinshasa, Democratic Republic of the Congo; Institute for Medical Immunology, Université Libre de Bruxelles, Brussells, Belgium
| | | | - Carole Else Eboumbou Moukoko
- Faculté de Médecine et des Sciences Pharmaceutiques, Université de Douala, Douala, Cameroon; Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroon
| | - Marielle Karine Bouyou Akotet
- Département de Parasitologie Mycologie Médecine Tropicale, Faculté de Médecine de l'Université des Sciences de la Santé, Libreville, Gabon; Centre de Recherche Biomédicale en Pathogènes Infectieux et Pathologies Associées, CREIPA, Université des Sciences de la Santé, Libreville, Gabon
| | - Tatfeng Youtchou Mirabeau
- Department of Medical Laboratory Science, Faculty of Basic Medical Sciences, College of Health Sciences, Niger Delta University, Wilberforce Island, Nigeria
| | - Sylvie Manguin
- Hydro Sciences Montpellier, Université de Montpellier, CNRS, IRD, Montpellier, France
| | - Doudou Malekita Yobi
- Department of Basic Sciences, Faculty of Medicine, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Jean Akiana
- Laboratoire National de Santé Publique, Université Marien Ngouabi, Brazzaville, Republic of the Congo
| | - Lady Charlène Kouna
- Unité d'Evolution Epidémiologie et Résistances Parasitaires, Centre Interdisciplinaire de Recherches Médicales de Franceville, Franceville, Gabon; Département de Parasitologie-Mycologie, Université des Sciences de la Santé, Libreville, Gabon
| | - Denise Patricia Mawili Mboumba
- Département de Parasitologie Mycologie Médecine Tropicale, Faculté de Médecine de l'Université des Sciences de la Santé, Libreville, Gabon; Centre de Recherche Biomédicale en Pathogènes Infectieux et Pathologies Associées, CREIPA, Université des Sciences de la Santé, Libreville, Gabon
| | - Dominique Fatima Voumbo-Matoumona
- Laboratoire National de Santé Publique, Université Marien Ngouabi, Brazzaville, Republic of the Congo; Unité d'Evolution Epidémiologie et Résistances Parasitaires, Centre Interdisciplinaire de Recherches Médicales de Franceville, Franceville, Gabon; Département de Parasitologie-Mycologie, Université des Sciences de la Santé, Libreville, Gabon
| | - Alliance-Laure Otam
- Institut Toulousain des Maladies Infectieuses et Inflammatoires (Infinity), Université de Toulouse, CNRS UMR5051, INSERM UMR 1291, UPS, Toulouse, France
| | | | | | - Elisabeth Kwanai
- Coordination diocésaine de la Santé, Diocèse de Maroua-Mokolo, Maroua, Cameroon
| | - Olivia Cohen
- Institut Toulousain des Maladies Infectieuses et Inflammatoires (Infinity), Université de Toulouse, CNRS UMR5051, INSERM UMR 1291, UPS, Toulouse, France
| | - Xavier Iriart
- Institut Toulousain des Maladies Infectieuses et Inflammatoires (Infinity), Université de Toulouse, CNRS UMR5051, INSERM UMR 1291, UPS, Toulouse, France; Département de Parasitologie et Mycologie, CHU Toulouse, Toulouse, France
| | - Lawrence Ayong
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroon
| | - Jean Bernard Lekana-Douki
- Unité d'Evolution Epidémiologie et Résistances Parasitaires, Centre Interdisciplinaire de Recherches Médicales de Franceville, Franceville, Gabon; Département de Parasitologie-Mycologie, Université des Sciences de la Santé, Libreville, Gabon
| | - Frédéric Ariey
- INSERM U1016, Institut Cochin, Laboratoire de Parasitologie-Mycologie, Hôpital Cochin, AP-HP, Université Paris Cité, Paris, France
| | - Antoine Berry
- Institut Toulousain des Maladies Infectieuses et Inflammatoires (Infinity), Université de Toulouse, CNRS UMR5051, INSERM UMR 1291, UPS, Toulouse, France; Département de Parasitologie et Mycologie, CHU Toulouse, Toulouse, France.
| |
Collapse
|
2
|
Shintouo CM, Shey RA, Yengo BN, Yaah NE, Teh RN, Ngwese RA, Ayong L, Vanhamme L, Souopgui J, Ghogomu SM, Njemini R. Effects of the suspension of mass drug administration during the COVID-19 pandemic on onchocerciasis prevalence in the Bandjoun and Massangam health districts, West Region of Cameroon. Acta Trop 2023; 246:106999. [PMID: 37549841 DOI: 10.1016/j.actatropica.2023.106999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 07/26/2023] [Accepted: 08/04/2023] [Indexed: 08/09/2023]
Abstract
Onchocerciasis is an infectious disease of public health and socio-economic importance in most parts of Sub-Saharan Africa. The objective of this study was to evaluate the effects of the suspension of implementation activities towards combating onchocerciasis in the Bandjoun and Massangam health districts in the West Region of Cameroon as a consequence of the COVID-19 pandemic. Data on socio-demographic and clinical characteristics were obtained using a structured questionnaire. All participants in both health districts were examined for the presence of clinical manifestations of onchocerciasis. In addition, two skin snips were obtained from the knee of each participant and examined for the presence of microfilaria. All data were categorized, coded, entered in a database, and analysed using SPSS version 23.0. A total of 229 participants in the Bandjoun health district and 378 in the Massangam health district were recruited for the study. In both health districts, there was no significant difference between male and female participants in terms of the clinical manifestations of onchocerciasis. The prevalence of nodules was 8.7% in the Bandjoun health district and 20.6% in the Massangam health district while the prevalence of microfilaria carriers in Bandjoun and Massangam health districts was 3.5% and 3.7%, respectively. Except for the Tsesse and Lemgo communities in the Bandjoun health district, there was a reduction in the prevalence of microfilaria in the communities that were studied when compared to previous data obtained before the disruption of control programmes activities. Overall, in both health districts, elderly individuals bear the largest burden of onchocerciasis. Based on the results obtained, we conclude that the temporary suspension of Neglected Tropical Disease control programme activities by the World Head Organization as a result of COVID-19 may have resulted to recrudescence of O. volvulus transmission in hypoendemic communities in the Bandjoun health district.
Collapse
Affiliation(s)
- Cabirou Mounchili Shintouo
- Department of Gerontology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels, Belgium; Frailty in Ageing Research Group, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels, Belgium; Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, P.O. Box 63 Buea, Cameroon
| | - Robert Adamu Shey
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, P.O. Box 63 Buea, Cameroon; Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies Campus, 126040 Gosselies, Belgium
| | - Bernis Neneyoh Yengo
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, P.O. Box 63 Buea, Cameroon
| | - Ntang Emmaculate Yaah
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, P.O. Box 63 Buea, Cameroon
| | - Rene Ning Teh
- Department of Zoology and Animal Physiology, University of Buea, Buea, Cameroon
| | - Roland Akwelle Ngwese
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, P.O. Box 63 Buea, Cameroon
| | - Lawrence Ayong
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde´, Cameroon
| | - Luc Vanhamme
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies Campus, 126040 Gosselies, Belgium
| | - Jacob Souopgui
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies Campus, 126040 Gosselies, Belgium.
| | - Stephen Mbigha Ghogomu
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, P.O. Box 63 Buea, Cameroon.
| | - Rose Njemini
- Department of Gerontology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels, Belgium; Frailty in Ageing Research Group, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels, Belgium.
| |
Collapse
|
3
|
Biabi MFAB, Fogang B, Essangui E, Maloba F, Donkeu C, Keumoe R, Cheteug G, Magoudjou N, Slam C, Kemleu S, Efange N, Perraut R, Nsango SE, Eboumbou Moukoko CE, Assam JPA, Etoa FX, Lamb T, Ayong L. High Prevalence of Polyclonal Plasmodium falciparum Infections and Association with Poor IgG Antibody Responses in a Hyper-Endemic Area in Cameroon. Trop Med Infect Dis 2023; 8:390. [PMID: 37624328 PMCID: PMC10459087 DOI: 10.3390/tropicalmed8080390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 06/29/2023] [Accepted: 06/30/2023] [Indexed: 08/26/2023] Open
Abstract
Malaria remains a major public health problem worldwide, with eradication efforts thwarted by drug and insecticide resistance and the lack of a broadly effective malaria vaccine. In continuously exposed communities, polyclonal infections are thought to reduce the risk of severe disease and promote the establishment of asymptomatic infections. We sought to investigate the relationship between the complexity of P. falciparum infection and underlying host adaptive immune responses in an area with a high prevalence of asymptomatic parasitaemia in Cameroon. A cross-sectional study of 353 individuals aged 2 to 86 years (median age = 16 years) was conducted in five villages in the Centre Region of Cameroon. Plasmodium falciparum infection was detected by multiplex nested PCR in 316 samples, of which 278 were successfully genotyped. Of these, 60.1% (167/278) were polyclonal infections, the majority (80.2%) of which were from asymptomatic carriers. Host-parasite factors associated with polyclonal infection in the study population included peripheral blood parasite density, participant age and village of residence. The number of parasite clones per infected sample increased significantly with parasite density (r = 0.3912, p < 0.0001) but decreased with participant age (r = -0.4860, p < 0.0001). Parasitaemia and the number of clones per sample correlated negatively with total plasma levels of IgG antibodies to three highly reactive P. falciparum antigens (MSP-1p19, MSP-3 and EBA175) and two soluble antigen extracts (merozoite and mixed stage antigens). Surprisingly, we observed no association between the frequency of polyclonal infection and susceptibility to clinical disease as assessed by the recent occurrence of malarial symptoms or duration since the previous fever episode. Overall, the data indicate that in areas with the high perennial transmission of P. falciparum, parasite polyclonality is dependent on underlying host antibody responses, with the majority of polyclonal infections occurring in persons with low levels of protective anti-plasmodial antibodies.
Collapse
Affiliation(s)
- Marie Florence A Bite Biabi
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon; (M.F.A.B.B.); (B.F.); (E.E.); (F.M.); (C.D.); (R.K.); (G.C.); (N.M.); (S.K.); (N.E.); (S.E.N.); (C.E.E.M.)
- Department of Biochemistry, Faculty of Science, University of Douala, Douala BP 2701, Cameroon
| | - Balotin Fogang
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon; (M.F.A.B.B.); (B.F.); (E.E.); (F.M.); (C.D.); (R.K.); (G.C.); (N.M.); (S.K.); (N.E.); (S.E.N.); (C.E.E.M.)
- Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde I, Yaounde BP 812, Cameroon
| | - Estelle Essangui
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon; (M.F.A.B.B.); (B.F.); (E.E.); (F.M.); (C.D.); (R.K.); (G.C.); (N.M.); (S.K.); (N.E.); (S.E.N.); (C.E.E.M.)
- Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala BP 2701, Cameroon
| | - Franklin Maloba
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon; (M.F.A.B.B.); (B.F.); (E.E.); (F.M.); (C.D.); (R.K.); (G.C.); (N.M.); (S.K.); (N.E.); (S.E.N.); (C.E.E.M.)
| | - Christiane Donkeu
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon; (M.F.A.B.B.); (B.F.); (E.E.); (F.M.); (C.D.); (R.K.); (G.C.); (N.M.); (S.K.); (N.E.); (S.E.N.); (C.E.E.M.)
- Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde I, Yaounde BP 812, Cameroon
| | - Rodrigue Keumoe
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon; (M.F.A.B.B.); (B.F.); (E.E.); (F.M.); (C.D.); (R.K.); (G.C.); (N.M.); (S.K.); (N.E.); (S.E.N.); (C.E.E.M.)
- Department of Biochemistry, Faculty of Science, University of Yaounde I, Yaounde BP 812, Cameroon
| | - Glwadys Cheteug
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon; (M.F.A.B.B.); (B.F.); (E.E.); (F.M.); (C.D.); (R.K.); (G.C.); (N.M.); (S.K.); (N.E.); (S.E.N.); (C.E.E.M.)
- Department of Medical Laboratory Sciences, Faculty of Science, University of Buea, Buea BP 63, Cameroon
| | - Nina Magoudjou
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon; (M.F.A.B.B.); (B.F.); (E.E.); (F.M.); (C.D.); (R.K.); (G.C.); (N.M.); (S.K.); (N.E.); (S.E.N.); (C.E.E.M.)
- Department of Biochemistry, Faculty of Science, University of Yaounde I, Yaounde BP 812, Cameroon
| | - Celine Slam
- Department of Pathology, School of Medicine, University of Utah, 15 N Medical Drive, Salt Lake City, UT 84112, USA;
| | - Sylvie Kemleu
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon; (M.F.A.B.B.); (B.F.); (E.E.); (F.M.); (C.D.); (R.K.); (G.C.); (N.M.); (S.K.); (N.E.); (S.E.N.); (C.E.E.M.)
| | - Noella Efange
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon; (M.F.A.B.B.); (B.F.); (E.E.); (F.M.); (C.D.); (R.K.); (G.C.); (N.M.); (S.K.); (N.E.); (S.E.N.); (C.E.E.M.)
- Department of Biochemistry, Faculty of Science, University of Buea, Buea BP 63, Cameroon
| | - Ronald Perraut
- Centre Pasteur du Cameroun Annex, Garoua BP 921, Cameroon;
| | - Sandrine Eveline Nsango
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon; (M.F.A.B.B.); (B.F.); (E.E.); (F.M.); (C.D.); (R.K.); (G.C.); (N.M.); (S.K.); (N.E.); (S.E.N.); (C.E.E.M.)
- Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala BP 2701, Cameroon
| | - Carole Else Eboumbou Moukoko
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon; (M.F.A.B.B.); (B.F.); (E.E.); (F.M.); (C.D.); (R.K.); (G.C.); (N.M.); (S.K.); (N.E.); (S.E.N.); (C.E.E.M.)
- Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala BP 2701, Cameroon
| | - Jean Paul Assam Assam
- Department of Microbiology, Faculty of Science, University of Yaounde I, Yaounde BP 812, Cameroon; (J.P.A.A.); (F.-X.E.)
| | - François-Xavier Etoa
- Department of Microbiology, Faculty of Science, University of Yaounde I, Yaounde BP 812, Cameroon; (J.P.A.A.); (F.-X.E.)
| | - Tracey Lamb
- Department of Pathology, School of Medicine, University of Utah, 15 N Medical Drive, Salt Lake City, UT 84112, USA;
| | - Lawrence Ayong
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon; (M.F.A.B.B.); (B.F.); (E.E.); (F.M.); (C.D.); (R.K.); (G.C.); (N.M.); (S.K.); (N.E.); (S.E.N.); (C.E.E.M.)
| |
Collapse
|
4
|
Vandermosten L, Prenen F, Fogang B, Dagneau de Richecour P, Knoops S, Donkeu CJ, Nguefack CDP, Taguebue JV, Ndombo PK, Ghesquière B, Ayong L, Van den Steen PE. Glucocorticoid dysfunction in children with severe malaria. Front Immunol 2023; 14:1187196. [PMID: 37492570 PMCID: PMC10364055 DOI: 10.3389/fimmu.2023.1187196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 06/23/2023] [Indexed: 07/27/2023] Open
Abstract
Introduction Malaria remains a widespread health problem with a huge burden. Severe or complicated malaria is highly lethal and encompasses a variety of pathological processes, including immune activation, inflammation, and dysmetabolism. Previously, we showed that adrenal hormones, in particular glucocorticoids (GCs), play critical roles to maintain disease tolerance during Plasmodium infection in mice. Here, GC responses were studied in Cameroon in children with uncomplicated malaria (UM), severe malaria (SM) and asymptomatic controls (AC). Methods To determine the sensitivity of leukocytes to GC signaling on a transcriptional level, we measured the ex vivo induction of glucocorticoid induced leucine zipper (GILZ) and FK506-binding protein 5 (FKBP5) by GCs in human and murine leukocytes. Targeted tracer metabolomics on peripheral blood mononuclear cells (PBMCs) was performed to detect metabolic changes induced by GCs. Results Total cortisol levels increased in patients with clinical malaria compared to AC and were higher in the SM versus UM group, while cortisol binding globulin levels were unchanged and adrenocorticotropic hormone (ACTH) levels were heterogeneous. Induction of both GILZ and FKBP5 by GCs was significantly reduced in patients with clinical malaria compared to AC and in malaria-infected mice compared to uninfected controls. Increased activity in the pentose phosphate pathway was found in the patients, but this was not affected by ex vivo stimulation with physiological levels of hydrocortisone. Interestingly, hydrocortisone induced increased levels of cAMP in AC, but not in clinical malaria patients. Discussion Altogether, this study shows that patients with SM have increased cortisol levels, but also a decreased sensitivity to GCs, which may clearly contribute to the severity of disease.
Collapse
Affiliation(s)
- Leen Vandermosten
- Laboratory of Immunoparasitology, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
| | - Fran Prenen
- Laboratory of Immunoparasitology, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
| | - Balotin Fogang
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroon
| | - Pauline Dagneau de Richecour
- Laboratory of Immunoparasitology, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
| | - Sofie Knoops
- Laboratory of Immunoparasitology, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
| | | | | | | | - Paul Koki Ndombo
- Mother and Child Center, Chantal Biya Foundation, Yaoundé, Cameroon
| | - Bart Ghesquière
- Metabolomics Expertise Center, Center for Cancer Biology, VIB Center for Cancer Biology, Leuven, Belgium
- Metabolomics Expertise Center, Department of Oncology, KU Leuven, Leuven, Belgium
| | - Lawrence Ayong
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroon
| | - Philippe E. Van den Steen
- Laboratory of Immunoparasitology, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
| |
Collapse
|
5
|
Eboumbou Moukoko CE, Kojom Foko LP, Ayina A, Tornyigah B, Epote AR, Penda IC, Epee Eboumbou P, Ebong SB, Texier G, Nsango SE, Ayong L, Tuikue Ndam N, Same Ekobo A. Effectiveness of Intermittent Preventive Treatment with Sulfadoxine-Pyrimethamine in Pregnancy: Low Coverage and High Prevalence of Plasmodium falciparum dhfr-dhps Quintuple Mutants as Major Challenges in Douala, an Urban Setting in Cameroon. Pathogens 2023; 12:844. [PMID: 37375534 DOI: 10.3390/pathogens12060844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 06/02/2023] [Accepted: 06/17/2023] [Indexed: 06/29/2023] Open
Abstract
Intermittent preventive treatment in pregnancy with sulfadoxine and pyrimethamine (IPTp-SP) is a key component in the malaria control strategy implemented in Africa. The aim of this study was to determine IPTp-SP adherence and coverage, and the impact on maternal infection and birth outcomes in the context of widespread SP resistance in the city of Douala, Cameroon. Clinical and demographic information were documented among 888 pregnant women attending 3 health facilities, from the antenatal care visit to delivery. Positive samples were genotyped for P. falciparum gene (dhfr, dhps, and k13) mutations. The overall IPTp-SP coverage (≥three doses) was 17.5%, and 5.1% received no dose. P. falciparum prevalence was 16%, with a predominance of submicroscopic infections (89.3%). Malaria infection was significantly associated with locality and history of malaria, and it was reduced among women using indoor residual spraying. Optimal doses of IPTp-SP were significantly associated with reduced infection among newborns and women (secundiparous and multiparous), but there was no impact of IPTp-SP on the newborn bodyweight. Pfdhfr-Pfdhps quintuple mutants were over-represented (IRNI-FGKAA, IRNI-AGKAA), and sextuple mutants (IRNI-AGKAS, IRNI-FGEAA, IRNI-AGKGS) were also reported. The Pfk13 gene mutations associated with artemisinin resistance were not detected. This study highlights the role of ANC in achieving optimal SP coverage in pregnant women, the mitigated impact of IPTp-SP on malaria outcomes, and the high prevalence of multiple SP-resistant P. falciparum parasites in the city of Douala that could compromise the efficacy of IPTp-SP.
Collapse
Affiliation(s)
- Carole Else Eboumbou Moukoko
- Malaria Research Unit, Centre Pasteur Cameroon, Yaoundé P.O. Box 1274, Cameroon
- Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, The University of Douala, Douala P.O. Box 24157, Cameroon
- Laboratory of Parasitology, Mycology and Virology, Postgraduate Training Unit for Health Sciences, Postgraduate School for Pure and Applied Sciences, The University of Douala, Douala P.O. Box 24157, Cameroon
| | | | - Angèle Ayina
- Malaria Research Unit, Centre Pasteur Cameroon, Yaoundé P.O. Box 1274, Cameroon
- Pharmaceutical Sciences Department, Faculty of Medicine and Pharmaceutical Sciences, The University of Douala, Douala P.O. Box 24157, Cameroon
| | - Bernard Tornyigah
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Accra P.O. Box 1181, Ghana
- UMR 261 MERIT, Institut de Recherche pour le Développement (IRD), Université de Paris, 75006 Paris, France
| | - Annie Rachel Epote
- Haematology Laboratory, Centre Pasteur Cameroon, Yaoundé P.O. Box 1274, Cameroon
| | - Ida Calixte Penda
- Clinical Sciences Department, Faculty of Medicine and Pharmaceutical Sciences, The University of Douala, Douala P.O. Box 24157, Cameroon
| | - Patricia Epee Eboumbou
- Clinical Sciences Department, Faculty of Medicine and Pharmaceutical Sciences, The University of Douala, Douala P.O. Box 24157, Cameroon
- Pediatric Wards, Bonassama Hospital, Douala P.O. Box 9023, Cameroon
| | - Serge Bruno Ebong
- Animal Organisms Biology and Physiology Department, Faculty of Sciences, The University of Douala, Douala P.O. Box 24157, Cameroon
| | - Gaetan Texier
- UMR 257-Vecteurs, Infections Tropicales et Méditerranéennes-VITROME-IRD/SSA/AP-HM, Aix-Marseille University, 13005 Marseille, France
| | - Sandrine Eveline Nsango
- Malaria Research Unit, Centre Pasteur Cameroon, Yaoundé P.O. Box 1274, Cameroon
- Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, The University of Douala, Douala P.O. Box 24157, Cameroon
| | - Lawrence Ayong
- Malaria Research Unit, Centre Pasteur Cameroon, Yaoundé P.O. Box 1274, Cameroon
| | - Nicaise Tuikue Ndam
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Accra P.O. Box 1181, Ghana
- UMR 261 MERIT, Institut de Recherche pour le Développement (IRD), Université de Paris, 75006 Paris, France
| | - Albert Same Ekobo
- Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, The University of Douala, Douala P.O. Box 24157, Cameroon
| |
Collapse
|
6
|
Sandie AB, Ngo Sack F, Medi Sike CI, Mendimi Nkodo J, Ngegni H, Ateba Mimfoumou HG, Lobe SA, Choualeu Noumbissi D, Tchuensou Mfoubi F, Tagnouokam Ngoupo PA, Ayong L, Njouom R, Tejiokem MC. Spread of SARS-CoV-2 Infection in Adult Populations in Cameroon: A Repeated Cross-Sectional Study Among Blood Donors in the Cities of Yaoundé and Douala. J Epidemiol Glob Health 2023; 13:266-278. [PMID: 37129837 PMCID: PMC10152017 DOI: 10.1007/s44197-023-00102-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 04/11/2023] [Indexed: 05/03/2023] Open
Abstract
Over a period of about 9 months, we conducted three serosurveys in the two major cities of Cameroon to determine the prevalence of SARS-COV-2 antibodies and to identify factors associated with seropositivity in each survey. We conducted three independent cross-sectional serosurveys of adult blood donors at the Central Hospital in Yaoundé (CHY), the Jamot Hospital in Yaoundé (JHY) and at the Laquintinie Hospital in Douala (LHD) who consented in writing to participate. Before blood sampling, a short questionnaire was administered to participants to collect their sociodemographic and clinical characteristics. We included a total of 743, 1202, and 1501 participants in the first (January 25-February 15, 2021), second (May 03-28, 2021), and third (November 29-December 31, 2021) surveys, respectively. The adjusted seroprevalence increased from 66.3% (95% CrI 61.1-71.3) in the first survey to 87.2% (95% CrI 84.0-90.0) in the second survey, and 98.4% (95% CrI 96.8-99.7) in the third survey. In the first survey, study site, participant occupation, and comorbid conditions were associated with SARS-CoV-2 seropositivity, whereas only study site remained associated in the second survey. None of the factors studied was significantly associated with seropositivity in the third survey. Together, the data suggest a rapid initial spread of SARS-CoV-2 in the study population, independent of the sociodemographic parameters assessed.
Collapse
Affiliation(s)
- Arsène Brunelle Sandie
- Service d’épidémiologie Et de Santé Publique, Centre Pasteur du Cameroun, 451, Street 2005, Yaounde 2, P.O. Box: 1274, Yaoundé, Cameroon
- African Population and Health Research Center, Dakar, Senegal
| | | | | | | | | | | | | | - Diane Choualeu Noumbissi
- Service d’épidémiologie Et de Santé Publique, Centre Pasteur du Cameroun, 451, Street 2005, Yaounde 2, P.O. Box: 1274, Yaoundé, Cameroon
| | - Fabrice Tchuensou Mfoubi
- Service d’épidémiologie Et de Santé Publique, Centre Pasteur du Cameroun, 451, Street 2005, Yaounde 2, P.O. Box: 1274, Yaoundé, Cameroon
| | | | - Lawrence Ayong
- Service de Paludisme, Centre Pasteur du Cameroun, Yaoundé, Cameroon
| | - Richard Njouom
- Service de Virologie, Centre Pasteur du Cameroun, Yaoundé, Cameroon
| | - Mathurin Cyrille Tejiokem
- Service d’épidémiologie Et de Santé Publique, Centre Pasteur du Cameroun, 451, Street 2005, Yaounde 2, P.O. Box: 1274, Yaoundé, Cameroon
| |
Collapse
|
7
|
Akeumbiwo Tchumkam C, Kojom Foko LP, Ndo C, Essangui Same E, Cheteug Nguetsa G, Eya'Ane Meva F, Ayong L, Eboumbou Moukoko CE. Chemical composition and repellent activity of essential oils of Tithonia diversifolia (Asteraceae) leaves against the bites of Anopheles coluzzii. Sci Rep 2023; 13:6001. [PMID: 37045885 PMCID: PMC10097857 DOI: 10.1038/s41598-023-31791-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 03/17/2023] [Indexed: 04/14/2023] Open
Abstract
Tithonia diversifolia is widely used in African traditional medicine for the treatment of a large number of ailments and disorders, including malaria. In the present study, we evaluated the repellent activity of essential oils (EO) of this plant against Anopheles coluzzii, a major vector of malaria in Africa. Fresh leaves of T. diversifolia were used to extract EO, which were used to perform repellency assays in the laboratory and in the field using commercially available N,N-Diethyl-meta-toluamide (DEET) and Cymbopogon (C.) citratus EO as positive controls and vaseline as negative control. The repellency rates and durations of protection of the human volunteers involved were used as measures of repellent activity. Chemical composition of the T. diversifolia EO was established further by gas chromatography coupled with mass spectrometry. The moisture content and oil yield were 81% and 0.02% respectively. A total of 29 compounds in the T. diversifolia EO was identified, with D-limonene (20.1%), α-Copaene (10.3%) and o-Cymene (10.0%) as the most represented. In field studies, the mean time of protection against mosquito bites was significantly lower in T. diversifolia EO-treated volunteers compared to treatments with C. citratus EO (71 min versus 125 min, p = 0.04), but significantly higher when compared with the non-treated volunteers (71 min vs 0.5 min, p = 0.03). The same pattern was found in laboratory repellency assays against A. coluzzii. In contrast, repulsion rates were statistically similar between T. diversifolia EO and positive controls. In conclusion, the study suggests promising repellent potential of leaves of T. diversifolia EO against A. coluzzii.
Collapse
Affiliation(s)
- Cédric Akeumbiwo Tchumkam
- Department of Pharmaceutical Sciences, Inorganic Chemistry Lab, Faculty of Medicine and Pharmaceutical Sciences, The University of Douala, P.O. Box 2701, Douala, Cameroon
| | - Loick Pradel Kojom Foko
- Department of Animal Biology, Faculty of Science, The University of Douala, P.O. Box 24157, Douala, Cameroon
| | - Cyrille Ndo
- Department of Biological Sciences, Parasitology Lab, Faculty of Medicine and Pharmaceutical Sciences, The University of Douala, P.O. Box 2701, Douala, Cameroon
- Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), Research Institut of Yaoundé, 288, Yaoundé, Cameroon
| | - Estelle Essangui Same
- Department of Animal Biology, Faculty of Science, The University of Douala, P.O. Box 24157, Douala, Cameroon
| | | | - François Eya'Ane Meva
- Department of Pharmaceutical Sciences, Inorganic Chemistry Lab, Faculty of Medicine and Pharmaceutical Sciences, The University of Douala, P.O. Box 2701, Douala, Cameroon
| | - Lawrence Ayong
- Malaria Research Unit, Centre Pasteur Cameroon, P.O. Box 1274, Yaoundé, Cameroon
| | - Carole Else Eboumbou Moukoko
- Department of Biological Sciences, Parasitology Lab, Faculty of Medicine and Pharmaceutical Sciences, The University of Douala, P.O. Box 2701, Douala, Cameroon.
- Malaria Research Unit, Centre Pasteur Cameroon, P.O. Box 1274, Yaoundé, Cameroon.
- Laboratory of Parasitology, Mycology and Virology, Postgraduate Training Unit for Health Sciences, Postgraduate School for Pure and Applied Sciences, University of Douala, P.O Box 24157, Douala, Cameroon.
| |
Collapse
|
8
|
Djoumessi AK, Nono RN, Neumann B, Stammler HG, Bitchagno GTM, Efange NM, Nkenfou CN, Ayong L, Lenta BN, Sewald N, Nkeng-Efouet-Alango P, Chouna JR. Constituents of the Stem Bark of Trichilia monadelpha (Thonn.) J. J. De Wilde (Meliaceae) and Their Antibacterial and Antiplasmodial Activities. Metabolites 2023; 13:metabo13020298. [PMID: 36837917 PMCID: PMC9966138 DOI: 10.3390/metabo13020298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 01/31/2023] [Accepted: 02/04/2023] [Indexed: 02/19/2023] Open
Abstract
The chemical investigation of the EtOH extract from the stem bark of Trichilia monadelpha (Thonn.) J. J. De Wilde afforded two new limonoids (1 and 2): 24-acetoxy-21,25-dihydroxy-21,23-epoxytirucall-7-en-3-one (1) and (6R)-1-O-deacetylkhayanolide E (2), together with eleven known compounds (3-13), including additional limonoids, flavonoids, triterpenoids, steroids, and fatty acid. Their structures were determined using 1D- and 2D-NMR experiments, ESI mass spectrometry, and single crystal X-ray diffraction analysis. The antibacterial and antiplasmodial activities of the extracts, sub-extracts, fractions, and some of the isolated compounds were evaluated in known pathogenic strains, including Staphylococcus aureus and Plasmodium falciparum. Fraction E (n-Hex/EtOAc 30:70, v/v) showed significant activity against S. aureus ATCC 25923 with a MIC value of 3.90 µg/mL, while one of its constituents (epicatechin (9)) exhibited significant activity with MIC values of 7.80 µg/mL. Interestingly, grandifotane A (6) (IC50 = 1.37 µM) and khayanolide D (5) (IC50 = 1.68 µM) were highly active against the chloroquine-sensitive/sulfadoxine-resistant plasmodium falciparum 3D7 strain, unlike their corresponding plant extract and fractions.
Collapse
Affiliation(s)
| | - Raymond Ngansop Nono
- Department of Chemistry, Faculty of Science, University of Dschang, Dschang P.O. Box 67, Cameroon
| | - Beate Neumann
- Department of Chemistry, Inorganic and Structural Chemistry, Bielefeld University, P.O. Box 100131, 33501 Bielefeld, Germany
| | - Hans-Georg Stammler
- Department of Chemistry, Inorganic and Structural Chemistry, Bielefeld University, P.O. Box 100131, 33501 Bielefeld, Germany
| | | | | | - Celine Nguefeu Nkenfou
- Department of Biology, Higher Teacher Training College, University of Yaoundé 1, Yaoundé P.O. Box 47, Cameroon
- Molecular Biology Center, Yaoundé P.O. Box 14475, Cameroon
| | - Lawrence Ayong
- Centre Pasteur du Cameroun, Yaounde P.O. Box 1274, Cameroon
| | - Bruno Ndjakou Lenta
- Department of Chemistry, Higher Teacher Training College, University of Yaoundé 1, Yaoundé P.O. Box 47, Cameroon
| | - Norbert Sewald
- Department of Chemistry, Organic and Bioorganic Chemistry-OC3, Bielefeld University, P.O. Box 100131, 33501 Bielefeld, Germany
- Correspondence: (N.S.); (J.R.C.)
| | | | - Jean Rodolphe Chouna
- Department of Chemistry, Faculty of Science, University of Dschang, Dschang P.O. Box 67, Cameroon
- Correspondence: (N.S.); (J.R.C.)
| |
Collapse
|
9
|
Megnekou R, Nana CMM, Djontu JC, Bitye BMZ, Nana BC, Zangue BKT, Donkeu CJ, Essangui E, Salawiss RM, Seumko’o RNM, Ayong L, Leke RGF. Chemokine modulation in microscopic and submicroscopic Plasmodium falciparum malaria infection in women at delivery in Yaoundé, Cameroon. PLoS One 2023; 18:e0280615. [PMID: 36689438 PMCID: PMC9870109 DOI: 10.1371/journal.pone.0280615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 01/04/2023] [Indexed: 01/24/2023] Open
Abstract
In pregnancy-associated malaria, chemokines such as CXCL-4, CXCL-13, CXCL-16, and CCL-24 play critical roles in leucocyte trafficking to tissue sites in the infected placenta where inflammatory reactions are active. However, how plasma levels of these chemokines associate with Plasmodium falciparum placental malaria and pregnancy outcomes remains not well understood. The present study analyzed the plasma levels of CXCL-4, CXCL-13, CXCL-16, and CCL-24 chemokines in matched peripheral, placental and cord blood in relation with placental malaria (PM), and with submicroscopic parasitaemia. This was a retrospective case-control study (1:3 ratio) involving samples from 134 women (34 PM+ and 100 PM-) enrolled at delivery at the Marie Reine Health Center in Yaoundé, Cameroon between June 2013 and October 2018. Samples were collected just after delivery and used to diagnose microscopic and submicroscopic Plasmodium falciparum infections. Submicroscopic infections were detected by reverse transcription LAMP whereas chemokine levels were determined by Magnetic Luminex Screening Assay. Overall, PM was associated with increased plasma levels of CXCL-13 and CXCL-16 and low levels of CXCL-4 and CCL-24 in both peripheral and placental blood (0.0002 ≤ p ≤ 0.042). Similarly, CCL-24 levels in peripheral and placental blood samples were significantly lower in submicroscopically infected women compared to healthy controls (p = 0.04 and 0.02, respectively). Maternal hemoglobin levels increased with peripheral plasma levels of CXCL-4 (p = 0.005), CXCL-16 (p = 0.03), and CCL-24 (p = 0.002) while birth weight was lower for babies born from women with high levels of peripheral CXCL-13 (p = 0.0006) and low levels of cord CXCL-4 and CCL-24 (p = 0.02 and 0.08, respectively). Together the data suggest that low levels of CXCL-4 and CCL-24 coupled with high plasma levels of CXCL-13 and for a lesser extend CXCL-16 represent signatures of PM in the study population. These findings are relevant for understanding the immunopathogenesis of PM and developing new therapeutic or preventive strategies against severe PM outcomes.
Collapse
Affiliation(s)
- Rosette Megnekou
- Department of Animal Biology and Physiology of the Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon
- The Immunology Laboratory of the Biotechnology Center, University of Yaoundé I, Yaoundé, Cameroon
| | - Chris Marco Mbianda Nana
- Department of Animal Biology and Physiology of the Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon
- The Immunology Laboratory of the Biotechnology Center, University of Yaoundé I, Yaoundé, Cameroon
| | - Jean Claude Djontu
- The Immunology Laboratory of the Biotechnology Center, University of Yaoundé I, Yaoundé, Cameroon
| | - Bernard Marie Zambo Bitye
- Department of Animal Biology and Physiology of the Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon
- The Immunology Laboratory of the Biotechnology Center, University of Yaoundé I, Yaoundé, Cameroon
| | - Benderli Christine Nana
- Department of Animal Biology and Physiology of the Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon
- The Immunology Laboratory of the Biotechnology Center, University of Yaoundé I, Yaoundé, Cameroon
| | - Berenice Kenfack Tekougang Zangue
- Department of Animal Biology and Physiology of the Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon
- The Immunology Laboratory of the Biotechnology Center, University of Yaoundé I, Yaoundé, Cameroon
| | | | - Estelle Essangui
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroon
| | - Rodrigue Mbea Salawiss
- Department of Animal Biology and Physiology of the Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon
- The Immunology Laboratory of the Biotechnology Center, University of Yaoundé I, Yaoundé, Cameroon
| | - Reine Ndeumou Medouen Seumko’o
- Department of Animal Biology and Physiology of the Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon
- The Immunology Laboratory of the Biotechnology Center, University of Yaoundé I, Yaoundé, Cameroon
| | - Lawrence Ayong
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroon
| | - Rose Gana Fomban Leke
- The Immunology Laboratory of the Biotechnology Center, University of Yaoundé I, Yaoundé, Cameroon
| |
Collapse
|
10
|
Shey RA, Ghogomu SM, Nebangwa DN, Shintouo CM, Yaah NE, Yengo BN, Nkemngo FN, Esoh KK, Tchatchoua NMT, Mbachick TT, Dede AF, Lemoge AA, Ngwese RA, Asa BF, Ayong L, Njemini R, Vanhamme L, Souopgui J. Rational design of a novel multi-epitope peptide-based vaccine against Onchocerca volvulus using transmembrane proteins. Front Trop Dis 2022. [DOI: 10.3389/fitd.2022.1046522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Almost a decade ago, it was recognized that the global elimination of onchocerciasis by 2030 will not be feasible without, at least, an effective prophylactic and/or therapeutic vaccine to complement chemotherapy and vector control strategies. Recent advances in computational immunology (immunoinformatics) have seen the design of novel multi-epitope onchocerciasis vaccine candidates which are however yet to be evaluated in clinical settings. Still, continued research to increase the pool of vaccine candidates, and therefore the chance of success in a clinical trial remains imperative. Here, we designed a multi-epitope vaccine candidate by assembling peptides from 14 O. volvulus (Ov) proteins using an immunoinformatics approach. An initial 126 Ov proteins, retrieved from the Wormbase database, and at least 90% similar to orthologs in related nematode species of economic importance, were screened for localization, presence of transmembrane domain, and antigenicity using different web servers. From the 14 proteins retained after the screening, 26 MHC-1 and MHC-II (T-cell) epitopes, and linear B-lymphocytes epitopes were predicted and merged using suitable linkers. The Mycobacterium tuberculosis Resuscitation-promoting factor E (RPFE_MYCTU), which is an agonist of TLR4, was then added to the N-terminal of the vaccine candidate as a built-in adjuvant. Immune simulation analyses predicted strong B-cell and IFN-γ based immune responses which are necessary for protection against O. volvulus infection. Protein-protein docking and molecular dynamic simulation predicted stable interactions between the 3D structure of the vaccine candidate and human TLR4. These results show that the designed vaccine candidate has the potential to stimulate both humoral and cellular immune responses and should therefore be subject to further laboratory investigation.
Collapse
|
11
|
Yengo BN, Shintouo CM, Hotterbeekx A, Yaah NE, Shey RA, Quanico J, Baggerman G, Ayong L, Vanhamme L, Njemini R, Souopgui J, Colebunders R, Ghogomu SM. Immunoinformatics Design and Assessment of a Multiepitope Antigen (OvMCBL02) for Onchocerciasis Diagnosis and Monitoring. Diagnostics (Basel) 2022; 12:diagnostics12061440. [PMID: 35741250 PMCID: PMC9221995 DOI: 10.3390/diagnostics12061440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 05/28/2022] [Accepted: 06/09/2022] [Indexed: 11/23/2022] Open
Abstract
Onchocerciasis is a Neglected Tropical Disease that has a significant socioeconomic impact, especially in Sub-Saharan Africa. Numerous reports indicate that the Expanded Special Project for the Elimination of Neglected Tropical Diseases needs novel diagnostic tools before achieving its goal of successful elimination of onchocerciasis in Africa. The current diagnostic tests are either invasive, insensitive, or not applicable in the field and about 25% of persons infected cannot mount immune responses against the single antigen used in the only approved Ov-16 serological test. In the quest to identify novel biomarkers that can be used to certify that a patient is free from the disease, evaluate the progress of elimination programmes, and conduct post elimination surveillances, mass spectrometric analysis of Onchocerca volvulus crude extract revealed that 1392 proteins are expressed in the adult and microfilariae stages of the parasite. Computational analysis predicted six of the proteins as O. volvulus potential diagnostic targets. Linear B-epitopes were predicted from the six proteins and used to construct a multiepitope antigen (OvMCBL02). Serological analysis revealed that the OvMCBL02 test significantly differentiated between serum samples of onchocerciasis patients from the Kombone Health Area in the South West Region of Cameroon (n = 63) and control serum samples from Rwanda (n = 29) and Europe (n = 26) as well as between serum samples from the onchocerciasis hyperendemic region of Kombone Health Area (n = 63) and the hypoendemic region of Bandjoun Health District (n = 54). Interestingly, the test did not cross-react with serum samples from patients suffering from related nematode infections, thereby suggesting that further characterization of the OvMCBL02 multiepitope antigen will render it an additional member of the diagnostic toolbox for the elimination of onchocerciasis.
Collapse
Affiliation(s)
- Bernis Neneyoh Yengo
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea P.O. Box 63, Cameroon; (B.N.Y.); (C.M.S.); (N.E.Y.); (R.A.S.)
| | - Cabirou Mounchili Shintouo
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea P.O. Box 63, Cameroon; (B.N.Y.); (C.M.S.); (N.E.Y.); (R.A.S.)
- Department of Gerontology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium;
- Frailty in Ageing Research Group, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium
| | - An Hotterbeekx
- Global Health Institute, University of Antwerp, 2610 Antwerp, Belgium; (A.H.); (R.C.)
- Molecular Pathology Group, Laboratory of Cell biology and Histology, University of Antwerp, 2610 Antwerp, Belgium
| | - Ntang Emmaculate Yaah
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea P.O. Box 63, Cameroon; (B.N.Y.); (C.M.S.); (N.E.Y.); (R.A.S.)
| | - Robert Adamu Shey
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea P.O. Box 63, Cameroon; (B.N.Y.); (C.M.S.); (N.E.Y.); (R.A.S.)
| | - Jusal Quanico
- Center for Proteomics, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium; (J.Q.); (G.B.)
| | - Geert Baggerman
- Center for Proteomics, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium; (J.Q.); (G.B.)
| | - Lawrence Ayong
- Malaria Research Unit, Centre Pasteur Cameroon, Yaoundé P.O. Box 1274, Cameroon;
| | - Luc Vanhamme
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Gosselies Campus, Université Libre de Bruxelles, 1070 Brussels, Belgium; (L.V.); (J.S.)
| | - Rose Njemini
- Department of Gerontology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium;
- Frailty in Ageing Research Group, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium
| | - Jacob Souopgui
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Gosselies Campus, Université Libre de Bruxelles, 1070 Brussels, Belgium; (L.V.); (J.S.)
| | - Robert Colebunders
- Global Health Institute, University of Antwerp, 2610 Antwerp, Belgium; (A.H.); (R.C.)
| | - Stephen Mbigha Ghogomu
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea P.O. Box 63, Cameroon; (B.N.Y.); (C.M.S.); (N.E.Y.); (R.A.S.)
- Correspondence: ; Tel.: +237-6-7845-5646
| |
Collapse
|
12
|
Fogang B, Biabi MF, Megnekou R, Maloba FM, Essangui E, Donkeu C, Cheteug G, Kapen M, Keumoe R, Kemleu S, Nsango S, Eboumbou C, Lamb TJ, Ayong L. High Prevalence of Asymptomatic Malarial Anemia and Association with Early Conversion from Asymptomatic to Symptomatic Infection in a Plasmodium falciparum Hyperendemic Setting in Cameroon. Am J Trop Med Hyg 2022; 106:293-302. [PMID: 34724628 PMCID: PMC8733519 DOI: 10.4269/ajtmh.21-0316] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 05/30/2021] [Indexed: 01/03/2023] Open
Abstract
Asymptomatic malarial parasitemia is highly prevalent in Plasmodium falciparum endemic areas and often associated with increased prevalence of mild to moderate anemia. The aim of this study was to assess the prevalence of anemia during asymptomatic malaria parasitemia and its interplay with persistent infection in highly exposed individuals. A household-based longitudinal survey was undertaken in a malaria hyperendemic area in Cameroon using multiplex nested polymerase chain reaction to detect plasmodial infections. Residents with P. falciparum asymptomatic parasitemia were monitored over a 3-week period with the aid of structured questionnaires and weekly measurements of axillary temperatures. Of the 353 individuals included (median age: 26 years, range 2-86 years, male/female sex ratio 0.9), 328 (92.9%) were positive for malaria parasitemia of whom 266 (81.1%) were asymptomatic carriers. The prevalence of anemia in the study population was 38.6%, of which 69.2% were asymptomatic. Multivariate analyses identified high parasitemia (> 327 parasites/µL) and female gender as associated risk factors of asymptomatic malarial anemia in the population. Furthermore, risk analyses revealed female gender and anemia at the time of enrolment as key predictors of early development of febrile illness (< 3 weeks post enrolment) among the asymptomatic individuals. Together, the data reveal an extremely high prevalence of asymptomatic malaria parasitemia and anemia in the study area, unveiling for the first time the association of asymptomatic malarial anemia with early clinical conversion from asymptomatic to symptomatic infection. Furthermore, these findings underscore the negative impact of asymptomatic malaria parasitemia on individual health, necessitating the development of appropriate control and preventive measures.
Collapse
Affiliation(s)
- Balotin Fogang
- Molecular Parasitology Laboratory, Centre Pasteur du Cameroun, Yaounde, Cameroon;,Department of Animal Biology and Physiology of the University of Yaoundé I, Yaounde, Cameroon
| | - Marie Florence Biabi
- Molecular Parasitology Laboratory, Centre Pasteur du Cameroun, Yaounde, Cameroon;,Department of Biochemistry, University of Douala, Douala, Cameroon
| | - Rosette Megnekou
- Department of Animal Biology and Physiology of the University of Yaoundé I, Yaounde, Cameroon
| | - Franklin M. Maloba
- Molecular Parasitology Laboratory, Centre Pasteur du Cameroun, Yaounde, Cameroon;,Department of Pathology, University of Utah, Salt Lake City, Utah
| | - Estelle Essangui
- Molecular Parasitology Laboratory, Centre Pasteur du Cameroun, Yaounde, Cameroon
| | - Christiane Donkeu
- Molecular Parasitology Laboratory, Centre Pasteur du Cameroun, Yaounde, Cameroon;,Department of Animal Biology and Physiology of the University of Yaoundé I, Yaounde, Cameroon
| | - Glwadys Cheteug
- Molecular Parasitology Laboratory, Centre Pasteur du Cameroun, Yaounde, Cameroon;,Department of Medical Laboratory Sciences, University of Buea, Buea, Cameroon
| | - Marie Kapen
- Molecular Parasitology Laboratory, Centre Pasteur du Cameroun, Yaounde, Cameroon
| | - Rodrigue Keumoe
- Molecular Parasitology Laboratory, Centre Pasteur du Cameroun, Yaounde, Cameroon
| | - Sylvie Kemleu
- Molecular Parasitology Laboratory, Centre Pasteur du Cameroun, Yaounde, Cameroon;,Department of Medical Laboratory Sciences, University of Buea, Buea, Cameroon
| | - Sandrine Nsango
- Molecular Parasitology Laboratory, Centre Pasteur du Cameroun, Yaounde, Cameroon
| | - Carole Eboumbou
- Molecular Parasitology Laboratory, Centre Pasteur du Cameroun, Yaounde, Cameroon
| | - Tracey J. Lamb
- Department of Pathology, University of Utah, Salt Lake City, Utah
| | - Lawrence Ayong
- Molecular Parasitology Laboratory, Centre Pasteur du Cameroun, Yaounde, Cameroon;,Address correspondence to Lawrence Ayong, Molecular Parasitology Laboratory, Centre Pasteur du Cameroun, BP 1274 Yaounde, Cameroon. E-mail:
| |
Collapse
|
13
|
Mairet-Khedim M, Nsango S, Ngou C, Menard S, Roesch C, Khim N, Srun S, Iriart X, Lanot T, Otam L, Abega F, Ayong L, Morlais I, Gandia P, Witkowski B, Berry A. Efficacy of dihydroartemisinin/piperaquine in patients with non-complicated Plasmodium falciparum malaria in Yaoundé, Cameroon. J Antimicrob Chemother 2021; 76:3037-3044. [PMID: 34453535 DOI: 10.1093/jac/dkab281] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 07/12/2021] [Indexed: 11/13/2022] Open
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.
Collapse
Affiliation(s)
- Mélissa Mairet-Khedim
- Malaria Translational Research Unit, Pasteur International Unit, Pasteur International Network, Phnom Penh, Cambodia and Paris, France.,Institut Toulousain des Maladies Infectieuses et Inflammatoires (Infinity), Université Toulouse, CNRS UMR5051, INSERM UMR1291, UPS, Toulouse, France.,Structural Microbiology Unit, Institut Pasteur, CNRS UMR 3528, 25 rue du Docteur Roux, 75724 Paris 15, France
| | - Sandrine Nsango
- Department of Biological Sciences, Faculté de Médecine et des Sciences Pharmaceutiques, Université de Douala, Douala, Cameroon.,Malaria Research Unit, Centre Pasteur du Cameroon, Yaoundé, Cameroon
| | - Christelle Ngou
- Malaria Research Unit, Centre Pasteur du Cameroon, Yaoundé, Cameroon.,MIVEGEC, IRD, CNRS, Univ. Montpellier, Montpellier, France
| | - Sandie Menard
- Institut Toulousain des Maladies Infectieuses et Inflammatoires (Infinity), Université Toulouse, CNRS UMR5051, INSERM UMR1291, UPS, Toulouse, France
| | - Camille Roesch
- Malaria Translational Research Unit, Pasteur International Unit, Pasteur International Network, Phnom Penh, Cambodia and Paris, France.,Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Nimol Khim
- Malaria Translational Research Unit, Pasteur International Unit, Pasteur International Network, Phnom Penh, Cambodia and Paris, France.,Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Sreynet Srun
- Malaria Translational Research Unit, Pasteur International Unit, Pasteur International Network, Phnom Penh, Cambodia and Paris, France.,Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Xavier Iriart
- Institut Toulousain des Maladies Infectieuses et Inflammatoires (Infinity), Université Toulouse, CNRS UMR5051, INSERM UMR1291, UPS, Toulouse, France.,Service de Parasitologie-Mycologie, Centre Hospitalier Universitaire de Toulouse, Hôpital Purpan, Toulouse F-31300, France
| | - Thomas Lanot
- Laboratoire de Pharmacocinétique et Toxicologie, Centre Hospitalier Universitaire de Toulouse, Hôpital Purpan, Toulouse F-31300, France
| | - Laure Otam
- Institut Toulousain des Maladies Infectieuses et Inflammatoires (Infinity), Université Toulouse, CNRS UMR5051, INSERM UMR1291, UPS, Toulouse, France.,Département des Sciences Biomédicales, Faculté des Sciences, Université de Ngaoundéré, Ngaoundéré, Cameroon
| | | | - Lawrence Ayong
- Malaria Research Unit, Centre Pasteur du Cameroon, Yaoundé, Cameroon
| | | | - Peggy Gandia
- Laboratoire de Pharmacocinétique et Toxicologie, Centre Hospitalier Universitaire de Toulouse, Hôpital Purpan, Toulouse F-31300, France.,INTHERES, Université de Toulouse, INRA, ENVT, BP 87614, 31076 Toulouse Cedex 3, France
| | - Benoit Witkowski
- Malaria Translational Research Unit, Pasteur International Unit, Pasteur International Network, Phnom Penh, Cambodia and Paris, France.,Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Antoine Berry
- Institut Toulousain des Maladies Infectieuses et Inflammatoires (Infinity), Université Toulouse, CNRS UMR5051, INSERM UMR1291, UPS, Toulouse, France.,Service de Parasitologie-Mycologie, Centre Hospitalier Universitaire de Toulouse, Hôpital Purpan, Toulouse F-31300, France
| |
Collapse
|
14
|
Li ZH, King TP, Ayong L, Asady B, Cai X, Rahman T, Vella SA, Coppens I, Patel S, Moreno SNJ. A plastid two-pore channel essential for inter-organelle communication and growth of Toxoplasma gondii. Nat Commun 2021; 12:5802. [PMID: 34608145 PMCID: PMC8490419 DOI: 10.1038/s41467-021-25987-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 09/06/2021] [Indexed: 01/04/2023] Open
Abstract
Two-pore channels (TPCs) are a ubiquitous family of cation channels that localize to acidic organelles in animals and plants to regulate numerous Ca2+-dependent events. Little is known about TPCs in unicellular organisms despite their ancient origins. Here, we characterize a TPC from Toxoplasma gondii, the causative agent of toxoplasmosis. TgTPC is a member of a novel clad of TPCs in Apicomplexa, distinct from previously identified TPCs and only present in coccidians. We show that TgTPC localizes not to acidic organelles but to the apicoplast, a non-photosynthetic plastid found in most apicomplexan parasites. Conditional silencing of TgTPC resulted in progressive loss of apicoplast integrity, severely affecting growth and the lytic cycle. Isolation of TPC null mutants revealed a selective role for TPCs in replication independent of apicoplast loss that required conserved residues within the pore-lining region. Using a genetically-encoded Ca2+ indicator targeted to the apicoplast, we show that Ca2+ signals deriving from the ER but not from the extracellular space are selectively transmitted to the lumen. Deletion of the TgTPC gene caused reduced apicoplast Ca2+ uptake and membrane contact site formation between the apicoplast and the ER. Fundamental roles for TPCs in maintaining organelle integrity, inter-organelle communication and growth emerge.
Collapse
Affiliation(s)
- Zhu-Hong Li
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, 30602, USA
| | - Thayer P King
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, 30602, USA
| | - Lawrence Ayong
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, 30602, USA
| | - Beejan Asady
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Heath, Baltimore, MD, 21205, USA
| | - Xinjiang Cai
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Taufiq Rahman
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD, USA
| | - Stephen A Vella
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, 30602, USA
| | - Isabelle Coppens
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Heath, Baltimore, MD, 21205, USA
| | - Sandip Patel
- Department of Cell and Developmental Biology, University College London, London, WC1E 6BT, UK
| | - Silvia N J Moreno
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, 30602, USA. .,Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA.
| |
Collapse
|
15
|
Feufack-Donfack LB, Sarah-Matio EM, Abate LM, Tuedom AGB, Bayibéki AN, Ngou CM, Toto JC, Sandeu MM, Moukoko CEE, Ayong L, Awono-Ambene P, Morlais I, Nsango SE. Correction to: Epidemiological and entomological studies of malaria transmission in Tibati, Adamawa region of Cameroon 6 years following the introduction of long-lasting insecticide nets. Parasit Vectors 2021; 14:512. [PMID: 34607611 PMCID: PMC8491378 DOI: 10.1186/s13071-021-04912-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Lionel Brice Feufack-Donfack
- Service de Paludisme du Centre Pasteur Cameroun, BP 1274, Yaounde, Cameroon.,CNRS UPR 9022, Inserm U 963, Université de Strasbourg, 2, allée Konrad Roentgen, 67084, Strasbourg Cedex, France
| | - Elangwe Milo Sarah-Matio
- Service de Paludisme du Centre Pasteur Cameroun, BP 1274, Yaounde, Cameroon.,UMR MIVEGEC, Institut de Recherche Pour Le Développement, IRD, CNRS, Université de Montpellier, 911 avenue Agropolis, 34394, Montpellier, France
| | - Luc Marcel Abate
- UMR MIVEGEC, Institut de Recherche Pour Le Développement, IRD, CNRS, Université de Montpellier, 911 avenue Agropolis, 34394, Montpellier, France
| | - Aline Gaelle Bouopda Tuedom
- Service de Paludisme du Centre Pasteur Cameroun, BP 1274, Yaounde, Cameroon.,Faculté de Médecine Et Des Sciences Pharmaceutiques de L'Université de Douala (FMSP-UD), BP 2701, Douala, Cameroon
| | - Albert Ngano Bayibéki
- Université Catholique D'Afrique Centrale, Yaoundé-Campus Messa, BP 1110, Yaounde, Cameroon
| | - Christelle Mafo Ngou
- Service de Paludisme du Centre Pasteur Cameroun, BP 1274, Yaounde, Cameroon.,UMR MIVEGEC, Institut de Recherche Pour Le Développement, IRD, CNRS, Université de Montpellier, 911 avenue Agropolis, 34394, Montpellier, France
| | - Jean-Claude Toto
- Laboratoire de Recherche Sur Le Paludisme, Organisation de Coordination Pour La Lutte Contre Les Endémies en Afrique Centrale, BP 288, Yaounde, Cameroon
| | - Maurice Marcel Sandeu
- Department of Medical Entomology, Centre for Research in Infectious Diseases, Yaounde, 13591, Cameroon.,Department of Microbiology and Infectious Diseases, School of Veterinary Medicine and Sciences, University of Ngaoundere, PO Box 454, Ngaoundere, Cameroon
| | - Carole Else Eboumbou Moukoko
- Service de Paludisme du Centre Pasteur Cameroun, BP 1274, Yaounde, Cameroon.,Faculté de Médecine Et Des Sciences Pharmaceutiques de L'Université de Douala (FMSP-UD), BP 2701, Douala, Cameroon
| | - Lawrence Ayong
- Service de Paludisme du Centre Pasteur Cameroun, BP 1274, Yaounde, Cameroon
| | - Parfait Awono-Ambene
- Laboratoire de Recherche Sur Le Paludisme, Organisation de Coordination Pour La Lutte Contre Les Endémies en Afrique Centrale, BP 288, Yaounde, Cameroon
| | - Isabelle Morlais
- Service de Paludisme du Centre Pasteur Cameroun, BP 1274, Yaounde, Cameroon.,UMR MIVEGEC, Institut de Recherche Pour Le Développement, IRD, CNRS, Université de Montpellier, 911 avenue Agropolis, 34394, Montpellier, France
| | - Sandrine Eveline Nsango
- Service de Paludisme du Centre Pasteur Cameroun, BP 1274, Yaounde, Cameroon. .,Faculté de Médecine Et Des Sciences Pharmaceutiques de L'Université de Douala (FMSP-UD), BP 2701, Douala, Cameroon.
| |
Collapse
|
16
|
Tuedom AGB, Sarah-Matio EM, Moukoko CEE, Feufack-Donfack BL, Maffo CN, Bayibeki AN, Awono-Ambene HP, Ayong L, Berry A, Abate L, Morlais I, Nsango SE. Antimalarial drug resistance in the Central and Adamawa regions of Cameroon: Prevalence of mutations in P. falciparum crt, Pfmdr1, Pfdhfr and Pfdhps genes. PLoS One 2021; 16:e0256343. [PMID: 34411157 PMCID: PMC8376100 DOI: 10.1371/journal.pone.0256343] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 08/05/2021] [Indexed: 11/19/2022] Open
Abstract
The spread of Plasmodium falciparum resistant parasites remains one of the major challenges for malaria control and elimination in Sub Saharan Africa. Monitoring of molecular markers conferring resistance to different antimalarials is important to track the spread of resistant parasites and to optimize the therapeutic lifespan of current drugs. This study aimed to evaluate the prevalence of known mutations in the drug resistance genes Pfcrt, Pfmdr1, Pfdhfr and Pfdhps in two different epidemiological settings in Cameroon. Dried blood spots collected in 2018 and 2019 from asymptomatic individuals were used for DNA extraction and then the Plasmodium infection status was determined byPCR. Detection of SNPs was performed by nested PCR followed by allele-specific restriction analysis (ASRA). The prevalence of each genotype was compared between sites using the Chi square and Fisher’s exact tests. A high prevalence of the Pfcrt K76 wild type allele was found in both sites (88.5 and 62.29% respectively; P< 0,0001). The prevalence of Pfmdr1 mutations 86Y and 1246Y was respectively 55.83 and 1.45% in Mfou and 45.87 and 5.97% in Tibati, with significant difference between the studied areas (P<0.0001). Overall, the Pfdhfr triple-mutant genotype (51I/59R/108N) was highly prevalent (> 96%), however no SNP was detected at codon 164. In Pfdhps, the prevalence of the 437G mutation reached (90%) and was at higher frequency in Mfou (P< 0.0001). Overall, the Pfdhps mutations 540E and 581G were less common (0.33 and 3.26%, respectively). The quadruple resistant genotype (Pfdhfr 51I/59R/108N+Pfdhp437G) was found almost 90% of the samples. The wild-type genotype (Pfdhfr N51/C59/S108/164I+Pfdhps A437/K540/A581) was never identified and the sextuple mutant (Pfdhfr 51I/59R/108N+Pfdhp437G/540E/581G), kwon as super resistant appeared in two samples from Tibati. These findings demonstrate declining trends in the prevalence of mutations conferring resistance to 4-aminoquinolines, especially to chloroquine. However, a high level of mutations in P. falciparum genes related to SP resistance was detected and this raises concerns about the future efficacy of IPTp-SP and SMC in Cameroon.
Collapse
Affiliation(s)
- Aline Gaelle Bouopda Tuedom
- Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroun
| | - Elangwe Milo Sarah-Matio
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroun
- UMR MIVEGEC, IRD, CNRS, Institut de Recherche pour le Développement, Université Montpellier, Montpellier Cedex, France
| | - Carole Else Eboumbou Moukoko
- Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroun
| | - Brice Lionel Feufack-Donfack
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroun
- CNRS UPR9022, INSERM U963, Strasbourg, France
| | - Christelle Ngou Maffo
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroun
- UMR MIVEGEC, IRD, CNRS, Institut de Recherche pour le Développement, Université Montpellier, Montpellier Cedex, France
| | - Albert Ngano Bayibeki
- Université Catholique d’Afrique Centrale, Yaoundé-Campus Messa Cameroun, Yaoundé, Cameroun
| | - Hermann Parfait Awono-Ambene
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), Yaoundé, Cameroun
| | - Lawrence Ayong
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroun
| | - Antoine Berry
- Service de Parasitologie-Mycologie, Centre Hospitalier Universitaire de Toulouse et UMR152 UPS-IRD, Université de Toulouse, Toulouse, France
| | - Luc Abate
- UMR MIVEGEC, IRD, CNRS, Institut de Recherche pour le Développement, Université Montpellier, Montpellier Cedex, France
| | - Isabelle Morlais
- UMR MIVEGEC, IRD, CNRS, Institut de Recherche pour le Développement, Université Montpellier, Montpellier Cedex, France
| | - Sandrine Eveline Nsango
- Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroun
- * E-mail: ,
| |
Collapse
|
17
|
W Akazong E, Tume C, Ayong L, Njouom R, Kenmoe S, Njankouo R, Kuiate JR. Cross-sectional hospital-based study on the seroprevalence of hepatitis B virus markers among healthcare workers, NWR, Cameroon. BMJ Open 2021; 11:e045716. [PMID: 34210724 PMCID: PMC8252875 DOI: 10.1136/bmjopen-2020-045716] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Hepatitis B virus (HBV) infection is a major public health issue worldwide, with about 257 million people reported to be chronic carriers by the WHO fact sheet updated in 2018. HBV can be contracted via direct contact with infected body fluid and infection is almost always asymptomatic. Although healthcare workers (HCWs) are at high risk of HBV infection, little is known about the prevalence of the various HBV markers among HCWs in Cameroon. The present study was taken to evaluate the prevalence of different HBV serological markers among HCWs in the North-West Region of Cameroon. METHODS This cross-sectional hospital-based study was carried out between April and September 2017 during which 395 HCWs were recruited. The serum of the HCWs were tested for the presence of HBV core antibody, hepatitis B surface antibody, hepatitis B e antibody and hepatitis B surface antigen using Monalisa ELISA kits produced by BIO-RAD laboratories. Data were analysed using SPSS V.20.0. RESULTS Among the 395 participants, 270 (68.4%) of them were females, 187 (47.3%) had been exposed to HBV, 145 (36.7%) had resolved the infection, 42 (10.6%) were current HBV carriers, 10 (2.5%) were infective, 36 (9.1%) were vaccinated and 172 (43.5%) were still susceptible. Exposure to HBV, past infection and susceptibility were significantly associated with age while the rate of vaccination was significantly associated with the job of the HCW in the health facilities. CONCLUSION The prevalence of HBV exposure and infection among HCWs obtained in this study was high while the level of vaccination in this at-risk population was low. Adequate steps should be taken to sensitise this population on HBV and the vaccination procedure.
Collapse
Affiliation(s)
- Etheline W Akazong
- Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
| | - Christopher Tume
- Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
- Department of Biochemistry, University of Bamenda, Bambili, Cameroon
| | - Lawrence Ayong
- Malaria Unit, Centre Pasteur Cameroun, Yaounde, Cameroon
| | - Richard Njouom
- Department of Virology, Centre Pasteur of Cameroon, Yaounde, Cameroon
| | - Sebastien Kenmoe
- Department of Virology, Centre Pasteur of Cameroon, Yaounde, Cameroon
| | - Ripa Njankouo
- Department of Virology, Centre Pasteur of Cameroon, Yaounde, Cameroon
| | - Jules-Roger Kuiate
- Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
| |
Collapse
|
18
|
Keumoe R, Koffi JG, Dize D, Fokou PVT, Tchamgoue J, Ayong L, Ndjakou BL, Sewald N, Ngameni B, Boyom FF. Identification of 3,3'-O-dimethylellagic acid and apigenin as the main antiplasmodial constituents of Endodesmia calophylloides Benth and Hymenostegia afzelii (Oliver.) Harms. BMC Complement Med Ther 2021; 21:180. [PMID: 34187456 PMCID: PMC8243547 DOI: 10.1186/s12906-021-03352-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 06/11/2021] [Indexed: 11/17/2022] Open
Abstract
Background Endodesmia calophylloides and Hymenostegia afzelii belong to the Guttiferae and Caesalpiniaceae plant families with known uses in African ethno-medicine to treat malaria and several other diseases. This study aimed at identifying antiplasmodial natural products from selected crude extracts from H. afzelii and E. calophylloides and to assess their cytotoxicity. Methods The extracts from H. afzelii and E. calophylloides were subjected to bioassay-guided fractionation to identify antiplasmodial compounds. The hydroethanol and methanol stem bark crude extracts, fractions and isolated compounds were assessed for antiplasmodial activity against the chloroquine-sensitive 3D7 and multi-drug resistant Dd2 strains of Plasmodium falciparum using the SYBR green I fluorescence-based microdilution assay. Cytotoxicity of active extracts, fractions and compounds was determined on African green monkey normal kidney Vero and murine macrophage Raw 264.7 cell lines using the Resazurin-based viability assay. Results The hydroethanolic extract of H. afzelii stem bark (HasbHE) and the methanolic extract of E. calophylloides stem bark (EcsbM) exhibited the highest potency against both Pf3D7 (EC50 values of 3.32 ± 0.15 μg/mL and 7.40 ± 0.19 μg/mL, respectively) and PfDd2 (EC50 of 3.08 ± 0.21 μg/mL and 7.48 ± 0.07 μg/mL, respectively) strains. Both extracts showed high selectivity toward Plasmodium parasites (SI > 13). The biological activity-guided fractionation led to the identification of five compounds (Compounds 1–5) from HasbHE and one compound (Compound 6) from EcsbM. Of these, Compound 1 corresponding to apigenin (EC50Pf3D7, of 19.01 ± 0.72 μM and EC50PfDd2 of 16.39 ± 0.52 μM), and Compound 6 corresponding to 3,3′-O-dimethylellagic acid (EC50Pf3D7 of 4.27 ± 0.05 μM and EC50PfDd2 of 1.36 ± 0.47 μM) displayed the highest antiplasmodial activities. Interestingly, both compounds exhibited negligible cytotoxicity against both Vero and Raw 264.7 cell lines with selectivity indices greater than 9. Conclusions This study led to the identification of two potent antiplasmodial natural compounds, 3,3′-O-dimethylellagic acid and apigenin that could serve as starting points for further antimalarial drug discovery. Supplementary Information The online version contains supplementary material available at 10.1186/s12906-021-03352-9.
Collapse
Affiliation(s)
- Rodrigue Keumoe
- Antimicrobial and Biocontrol Agents Unit (AmBcAU), Laboratory for Phytobiochemistry and Medicinal Plants Studies, Department of Biochemistry, Faculty of Science, University of Yaoundé I, P.O. Box 812, Yaoundé, Cameroon.,Malaria Research Unit, Centre Pasteur du Cameroun, P.O. Box 1274, Yaoundé, Cameroon
| | - Jean Garba Koffi
- Higher Teachers Training College, University of Yaoundé I, P.O Box 47, Yaounde, Cameroon
| | - Darline Dize
- Antimicrobial and Biocontrol Agents Unit (AmBcAU), Laboratory for Phytobiochemistry and Medicinal Plants Studies, Department of Biochemistry, Faculty of Science, University of Yaoundé I, P.O. Box 812, Yaoundé, Cameroon
| | - Patrick Valère Tsouh Fokou
- Antimicrobial and Biocontrol Agents Unit (AmBcAU), Laboratory for Phytobiochemistry and Medicinal Plants Studies, Department of Biochemistry, Faculty of Science, University of Yaoundé I, P.O. Box 812, Yaoundé, Cameroon
| | - Joseph Tchamgoue
- Higher Teachers Training College, University of Yaoundé I, P.O Box 47, Yaounde, Cameroon
| | - Lawrence Ayong
- Malaria Research Unit, Centre Pasteur du Cameroun, P.O. Box 1274, Yaoundé, Cameroon
| | - Bruno Lenta Ndjakou
- Higher Teachers Training College, University of Yaoundé I, P.O Box 47, Yaounde, Cameroon
| | - Norbert Sewald
- Organic and Bioorganic Chemistry, Faculty of Chemistry, Bielefeld University, D-33501, Bielefeld, Germany
| | - Bathelemy Ngameni
- Laboratory of Pharmacognosy and Pharmaceutical Chemistry, Faculty of Medicine and Biomedical Sciences, University of Yaounde I, P.O Box 1364, Yaounde, Cameroon
| | - Fabrice Fekam Boyom
- Antimicrobial and Biocontrol Agents Unit (AmBcAU), Laboratory for Phytobiochemistry and Medicinal Plants Studies, Department of Biochemistry, Faculty of Science, University of Yaoundé I, P.O. Box 812, Yaoundé, Cameroon.
| |
Collapse
|
19
|
Feufack-Donfack LB, Sarah-Matio EM, Abate LM, Bouopda Tuedom AG, Ngano Bayibéki A, Maffo Ngou C, Toto JC, Sandeu MM, Eboumbou Moukoko CE, Ayong L, Awono-Ambene P, Morlais I, Nsango SE. Epidemiological and entomological studies of malaria transmission in Tibati, Adamawa region of Cameroon 6 years following the introduction of long-lasting insecticide nets. Parasit Vectors 2021; 14:247. [PMID: 33964974 PMCID: PMC8106832 DOI: 10.1186/s13071-021-04745-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 04/23/2021] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND Malaria remains a serious public health problem in Cameroon. Implementation of control interventions requires prior knowledge of the local epidemiological situation. Here we report the results of epidemiological and entomological surveys carried out in Tibati, Adamawa Region, Cameroon, an area where malaria transmission is seasonal, 6 years after the introduction of long-lasting insecticidal bed nets. METHODS Cross-sectional studies were carried out in July 2015 and 2017 in Tibati. Thick blood smears and dried blood spots were collected from asymptomatic and symptomatic individuals in the community and at health centers, respectively, and used for the molecular diagnosis of Plasmodium species. Adult mosquitoes were collected by indoor residual spraying and identified morphologically and molecularly. The infection status of Plasmodium spp. was determined by quantitative PCR, and positivity of PCR-positive samples was confirmed by Sanger sequencing. RESULTS Overall malaria prevalence in our study population was 55.0% (752/1367) and Plasmodium falciparum was the most prevalent parasite species (94.3%), followed by P. malariae (17.7%) and P. ovale (0.8%); 92 (12.7%) infections were mixed infections. Infection parameters varied according to clinical status (symptomatic/asymptomatic) and age of the sampled population and the collection sites. Infection prevalence was higher in asymptomatic carriers (60.8%), but asexual and sexual parasite densities were lower. Prevalence and intensity of infection decreased with age in both the symptomatic and asymptomatic groups. Heterogeneity in infections was observed at the neighborhood level, revealing hotspots of transmission. Among the 592 Anopheles mosquitoes collected, 212 (35.8%) were An. gambiae, 172 (29.1%) were An. coluzzii and 208 (35.1%) were An. funestus (s.s.). A total of 26 (4.39%) mosquito specimens were infected by Plasmodium sp. and the three Anopheles mosquitoes transmitted Plasmodium at equal efficiency. Surprisingly, we found an An. coluzzii specimen infected by Plasmodium vivax, which confirms circulation of this species in Cameroon. The positivity of all 26 PCR-positive Plasmodium-infected mosquitoes was successively confirmed by sequencing analysis. CONCLUSION Our study presents the baseline malaria parasite burden in Tibati, Adamawa Region, Cameroon. Our results highlight the high malaria endemicity in the area, and hotspots of disease transmission are identified. Parasitological indices suggest low bednet usage and that implementation of control interventions in the area is needed to reduce malaria burden. We also report for the first time a mosquito vector with naturally acquired P. vivax infection in Cameroon.
Collapse
Affiliation(s)
- Lionel Brice Feufack-Donfack
- Service de Paludisme du Centre Pasteur Cameroun, BP 1274, Yaounde, Cameroon
- CNRS UPR 9022, Inserm U 963, Université de Strasbourg, 2, allée Konrad Roentgen, 67084 Strasbourg Cedex, France
| | - Elangwe Milo Sarah-Matio
- Service de Paludisme du Centre Pasteur Cameroun, BP 1274, Yaounde, Cameroon
- UMR MIVEGEC, IRD, CNRS, Université de Montpellier, Institut de Recherche pour le Développement, 911 avenue Agropolis, 34394 Montpellier, France
| | - Luc Marcel Abate
- UMR MIVEGEC, IRD, CNRS, Université de Montpellier, Institut de Recherche pour le Développement, 911 avenue Agropolis, 34394 Montpellier, France
| | - Aline Gaelle Bouopda Tuedom
- Service de Paludisme du Centre Pasteur Cameroun, BP 1274, Yaounde, Cameroon
- Faculté de Médecine et des Sciences Pharmaceutiques de l’Université de Douala (FMSP–UD), BP 2701 Douala, Cameroon
| | - Albert Ngano Bayibéki
- Université Catholique d’Afrique Centrale, Yaoundé-Campus Messa, BP 1110, Yaounde, Cameroon
| | - Christelle Maffo Ngou
- Service de Paludisme du Centre Pasteur Cameroun, BP 1274, Yaounde, Cameroon
- UMR MIVEGEC, IRD, CNRS, Université de Montpellier, Institut de Recherche pour le Développement, 911 avenue Agropolis, 34394 Montpellier, France
| | - Jean-Claude Toto
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale, BP 288, Yaounde, Cameroon
| | - Maurice Marcel Sandeu
- Department of Medical Entomology, Centre for Research in Infectious Diseases, Yaounde, 13591 Cameroon
- Department of Microbiology and Infectious Diseases, School of Veterinary Medicine and Sciences, University of Ngaoundere, PO Box 454, Ngaoundere, Cameroon
| | - Carole Else Eboumbou Moukoko
- Service de Paludisme du Centre Pasteur Cameroun, BP 1274, Yaounde, Cameroon
- Faculté de Médecine et des Sciences Pharmaceutiques de l’Université de Douala (FMSP–UD), BP 2701 Douala, Cameroon
| | - Lawrence Ayong
- Service de Paludisme du Centre Pasteur Cameroun, BP 1274, Yaounde, Cameroon
| | - Parfait Awono-Ambene
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale, BP 288, Yaounde, Cameroon
| | - Isabelle Morlais
- Service de Paludisme du Centre Pasteur Cameroun, BP 1274, Yaounde, Cameroon
- UMR MIVEGEC, IRD, CNRS, Université de Montpellier, Institut de Recherche pour le Développement, 911 avenue Agropolis, 34394 Montpellier, France
| | - Sandrine Eveline Nsango
- Service de Paludisme du Centre Pasteur Cameroun, BP 1274, Yaounde, Cameroon
- Faculté de Médecine et des Sciences Pharmaceutiques de l’Université de Douala (FMSP–UD), BP 2701 Douala, Cameroon
| |
Collapse
|
20
|
Tiam ER, Bikobo DSN, Ndassa IM, Nyemeck Ii NM, A Zintchem AA, Ayong L, Diboué PHB, Ndjakou BL, Mbing JN, Pegnyemb DE. Experimental and computational studies of an antiplasmodial derivative of allantoin; antimycobacterial essential oil from Cordia batesii WERNHAM (Boraginaceae). BMC Chem 2021; 15:15. [PMID: 33673871 PMCID: PMC7934435 DOI: 10.1186/s13065-021-00742-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 02/22/2021] [Indexed: 11/13/2022] Open
Abstract
Background Chemical and pharmacological investigations were performed on the stems of Cordia batesii (Boraginaeae); chemical studies included quantum calculations applied on a newly described compound. Results A new derivative of allantoin (1) named batesiin (2) was characterized. Thirteen other known compounds involving allantoin (1) were either isolated or identified. GC–MS enabled the identification of six compounds from a fraction containing essential oil. MeOH extract and some isolated compounds were tested in vitro against Pf7G8 CQS and Pf Dd2 CQR strains of Plasmodium falciparum; extract disclosed a moderate antiplasmodial activity (IC50 = 50 μg mL−1). Meantime, the CH2Cl2 extract and essential oil fraction were tested on a resistant mycobacterial strain of Mycobacterium tuberculosis; a potent antimycobacterial activity with a MIC = 9.52 μg mL−1 was deduced from essential oil. Density functional theory (DFT) calculations were carried on batesiin (2). Calculated chemical shifts at B3LYP/6-31G(d,p) and MPW1PW91/6-31G+(d,p) showed much better correlations with the experimental data. Time dependent DFT at B3LYP/6-31G+(d,p) displayed a major absorption band 3.01 nm higher than the experimental value. Conclusion Cordia batesii can be considered as promising in search of compounds with antimalarial and antitubercular properties. DFT studies are very helpful when trying to learn more about the spectroscopic insights of a derivative of allantoin (1).
Collapse
Affiliation(s)
- Eric Robert Tiam
- Department of Organic Chemistry, Faculty of Science, University of Yaoundé I, P.O Box 812, Yaounde, Cameroon
| | | | - Ibrahim Mbouombouo Ndassa
- Department of Inorganic Chemistry, Faculty of Science, University of Yaoundé I, P.O Box 812, Yaounde, Cameroon.,Department of Chemistry, Higher Training College, University of Yaoundé I, P.O Box 47, Yaounde, Cameroon
| | - Norbert Mbabi Nyemeck Ii
- Department of Organic Chemistry, Faculty of Science, University of Yaoundé I, P.O Box 812, Yaounde, Cameroon
| | - Auguste Abouem A Zintchem
- Department of Organic Chemistry, Faculty of Science, University of Yaoundé I, P.O Box 812, Yaounde, Cameroon. .,Department of Chemistry, Higher Training College, University of Yaoundé I, P.O Box 47, Yaounde, Cameroon.
| | | | - Patrick Hervé Betote Diboué
- Centre for Research on Medicinal Plants and Traditional Medicine, Institute of Medical Research and Medicinal Plants Studies, Yaounde, Cameroon
| | - Bruno Lenta Ndjakou
- Department of Organic Chemistry, Faculty of Science, University of Yaoundé I, P.O Box 812, Yaounde, Cameroon.,Department of Chemistry, Higher Training College, University of Yaoundé I, P.O Box 47, Yaounde, Cameroon
| | - Joséphine Ngo Mbing
- Department of Organic Chemistry, Faculty of Science, University of Yaoundé I, P.O Box 812, Yaounde, Cameroon
| | - Dieudonné Emmanuel Pegnyemb
- Department of Organic Chemistry, Faculty of Science, University of Yaoundé I, P.O Box 812, Yaounde, Cameroon
| |
Collapse
|
21
|
Zebaze Temgoua Kemleu SG, Ngando L, Nguekeng E, Fogang B, Mafo Kapen M, Fopa SI, Biabi MF, Essangui E, Assob Nguedia JC, Ayong L. Diagnostic performance of a rapid whole blood-based RT-LAMP method for malaria diagnosis among apparently healthy blood donors and febrile neonates in Cameroon. PLoS One 2021; 16:e0246205. [PMID: 33508016 PMCID: PMC7842973 DOI: 10.1371/journal.pone.0246205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 01/14/2021] [Indexed: 11/23/2022] Open
Abstract
Light microscopy and rapid diagnostic tests are the two commonly used methods for malaria diagnosis that rely on the direct use of unprocessed blood samples. However, both methods do not have the level of sensitivity required for malaria diagnosis in cases of low density parasitaemia. We report here the diagnostic performance of a whole blood-based reverse transcription loop-mediated isothermal amplification method for Plasmodium falciparum malaria diagnosis in apparently healthy blood donors and febrile neonates in Cameroon. The presence of malaria parasites in whole blood samples was determined by light microscopy, antigen-based rapid diagnostic test (RDT), and by RT-LAMP using a "lyse and amplify" experimental protocol. Of the 256 blood donors tested, 36 (14.1%) were positive for malaria parasites by light microscopy, 38 (14.8%) were positive by RDT whereas 78 (30.5%) were positive by RT-LAMP. Only light microscopy and RT-LAMP detected infection among the febrile neonates (279 neonates, median age: 2 days, range: 1-9 days), with positivity rates of 8.6% and 12.2%, respectively. The overall concordance between the three methods were 75.9% for RT-LAMP and light microscopy, 75.1% for RT-LAMP and RDT, and 83.9% for light microscopy and RDT. Blood parasite densities were significantly lower in the neonates (mean: 97.6, range: 61-192 parasites/μL) compared to the blood donors (mean: 447.8, range: 63-11 000 parasites/μL). Together, the study demonstrates the usefulness of whole blood RT-LAMP for use in rapid pre-screening of blood donors and suspected neonates to avert severe consequences of P. falciparum infections.
Collapse
Affiliation(s)
- Sylvie Georgette Zebaze Temgoua Kemleu
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde, Cameroon
- Department of Medical Laboratory Sciences, Faculty of Health Sciences, University of Buea, Buea, Cameroon
| | - Laure Ngando
- Bacteriology Unit, Centre Pasteur du Cameroun, Yaounde, Cameroon
| | | | - Balotin Fogang
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde, Cameroon
| | - Marie Mafo Kapen
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde, Cameroon
| | | | | | - Estelle Essangui
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde, Cameroon
| | - Jules Clement Assob Nguedia
- Department of Medical Laboratory Sciences, Faculty of Health Sciences, University of Buea, Buea, Cameroon
- Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon
| | - Lawrence Ayong
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde, Cameroon
| |
Collapse
|
22
|
Shey RA, Ghogomu SM, Shintouo CM, Nkemngo FN, Nebangwa DN, Esoh K, Yaah NE, Manka’aFri M, Nguve JE, Ngwese RA, Njume FN, Bertha FA, Ayong L, Njemini R, Vanhamme L, Souopgui J. Computational Design and Preliminary Serological Analysis of a Novel Multi-Epitope Vaccine Candidate against Onchocerciasis and Related Filarial Diseases. Pathogens 2021; 10:99. [PMID: 33494344 PMCID: PMC7912539 DOI: 10.3390/pathogens10020099] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 01/14/2021] [Accepted: 01/18/2021] [Indexed: 11/16/2022] Open
Abstract
: Onchocerciasis is a skin and eye disease that exerts a heavy socio-economic burden, particularly in sub-Saharan Africa, a region which harbours greater than 96% of either infected or at-risk populations. The elimination plan for the disease is currently challenged by many factors including amongst others; the potential emergence of resistance to the main chemotherapeutic agent, ivermectin (IVM). Novel tools, including preventative and therapeutic vaccines, could provide additional impetus to the disease elimination tool portfolio. Several observations in both humans and animals have provided evidence for the development of both natural and artificial acquired immunity. In this study, immuno-informatics tools were applied to design a filarial-conserved multi-epitope subunit vaccine candidate, (designated Ov-DKR-2) consisting of B-and T-lymphocyte epitopes of eight immunogenic antigens previously assessed in pre-clinical studies. The high-percentage conservation of the selected proteins and epitopes predicted in related nematode parasitic species hints that the generated chimera may be instrumental for cross-protection. Bioinformatics analyses were employed for the prediction, refinement, and validation of the 3D structure of the Ov-DKR-2 chimera. In-silico immune simulation projected significantly high levels of IgG1, T-helper, T-cytotoxic cells, INF-γ, and IL-2 responses. Preliminary immunological analyses revealed that the multi-epitope vaccine candidate reacted with antibodies in sera from both onchocerciasis-infected individuals, endemic normals as well as loiasis-infected persons but not with the control sera from European individuals. These results support the premise for further characterisation of the engineered protein as a vaccine candidate for onchocerciasis.
Collapse
Affiliation(s)
- Robert Adamu Shey
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea 99999, Cameroon; (R.A.S.); (S.M.G.); (C.M.S.); (D.N.N.); (N.E.Y.); (M.M.); (J.E.N.); (R.A.N.); (F.N.N.)
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies Campus, 6040 Gosselies, Belgium;
| | - Stephen Mbigha Ghogomu
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea 99999, Cameroon; (R.A.S.); (S.M.G.); (C.M.S.); (D.N.N.); (N.E.Y.); (M.M.); (J.E.N.); (R.A.N.); (F.N.N.)
| | - Cabirou Mounchili Shintouo
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea 99999, Cameroon; (R.A.S.); (S.M.G.); (C.M.S.); (D.N.N.); (N.E.Y.); (M.M.); (J.E.N.); (R.A.N.); (F.N.N.)
- Frailty in Ageing Research Group, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels, Belgium;
- Department of Gerontology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels, Belgium
| | - Francis Nongley Nkemngo
- Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea 99999, Cameroon;
- Centre for Research in Infectious Diseases (CRID), Department of Parasitology and Medical Entomology, Yaounde BP 13591, Cameroon
| | - Derrick Neba Nebangwa
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea 99999, Cameroon; (R.A.S.); (S.M.G.); (C.M.S.); (D.N.N.); (N.E.Y.); (M.M.); (J.E.N.); (R.A.N.); (F.N.N.)
| | - Kevin Esoh
- Division of Human Genetics, Health Sciences Campus, Department of Pathology, University of Cape Town, Anzio Rd, Observatory, Cape Town 7925, South Africa;
| | - Ntang Emmaculate Yaah
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea 99999, Cameroon; (R.A.S.); (S.M.G.); (C.M.S.); (D.N.N.); (N.E.Y.); (M.M.); (J.E.N.); (R.A.N.); (F.N.N.)
| | - Muyanui Manka’aFri
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea 99999, Cameroon; (R.A.S.); (S.M.G.); (C.M.S.); (D.N.N.); (N.E.Y.); (M.M.); (J.E.N.); (R.A.N.); (F.N.N.)
| | - Joel Ebai Nguve
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea 99999, Cameroon; (R.A.S.); (S.M.G.); (C.M.S.); (D.N.N.); (N.E.Y.); (M.M.); (J.E.N.); (R.A.N.); (F.N.N.)
| | - Roland Akwelle Ngwese
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea 99999, Cameroon; (R.A.S.); (S.M.G.); (C.M.S.); (D.N.N.); (N.E.Y.); (M.M.); (J.E.N.); (R.A.N.); (F.N.N.)
| | - Ferdinand Ngale Njume
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea 99999, Cameroon; (R.A.S.); (S.M.G.); (C.M.S.); (D.N.N.); (N.E.Y.); (M.M.); (J.E.N.); (R.A.N.); (F.N.N.)
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies Campus, 6040 Gosselies, Belgium;
| | - Fru Asa Bertha
- Department of Public Health and Hygiene, Faculty of Health Science, University of Buea, Buea 99999, Cameroon;
| | - Lawrence Ayong
- Malaria Research Unit, Centre Pasteur Cameroon, Yaoundé Rue 2005, Cameroon;
| | - Rose Njemini
- Frailty in Ageing Research Group, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels, Belgium;
- Department of Gerontology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels, Belgium
| | - Luc Vanhamme
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies Campus, 6040 Gosselies, Belgium;
| | - Jacob Souopgui
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies Campus, 6040 Gosselies, Belgium;
| |
Collapse
|
23
|
Cheteug G, Elanga-Ndille E, Donkeu C, Ekoko W, Oloume M, Essangui E, Nwane P, NSango SE, Etang J, Wanji S, Ayong L, Eboumbou Moukoko CE. Preliminary validation of the use of IgG antibody response to Anopheles gSG6-p1 salivary peptide to assess human exposure to malaria vector bites in two endemic areas of Cameroon in Central Africa. PLoS One 2020; 15:e0242510. [PMID: 33382730 PMCID: PMC7774847 DOI: 10.1371/journal.pone.0242510] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 11/03/2020] [Indexed: 11/25/2022] Open
Abstract
The specific immune response to the Anopheles salivary peptide could be a pertinent and complementary tool to assess the risk of malaria transmission and the effectiveness of vector control strategies. This study aimed to obtain first reliable data on the current state of the Anopheles gSG6-P1 biomarker for assess the level of exposure to Anopheles bites in high malaria endemic areas in Cameroon. Blood smears were collected from people living in the neighborhoods of Youpwe (suburban area, continental) and Manoka (rural area, Island), both areas in the coastal region of Cameroon. Malaria infection was determined using thick blood smear microscopy, whereas the level of specific IgG response to gSG-P1 peptide was assessed by enzyme-linked immunosorbent assay from the dried blood spots. Of 266 (153 from Youpwe, 113 from Manoka) malaria endemic residents (mean age: 22.8±19.8 years, age range: 6 months–94 years, male/female sex ratio: 1/1.2, with Manoka mean age: 23.71±20.53, male/female sex ratio:1/1.13 and Youpwe mean age: 22.12±19.22, male/female sex ratio 1/0.67) randomly included in the study, Plasmodium infection prevalence was significantly higher in Manoka than in Youpwe (64.6% vs 12,4%, p = 0.0001). The anti-gSG6-P1 IgG response showed a high inter-individual heterogeneity and was significantly higher among individuals from Manoka than those from Youpwe (p = 0.023). Malaria infected individuals presented a higher anti-gSG6-P1 IgG antibody response than non-infected (p = 0.0004). No significant difference in the level of specific IgG response to gSG-P1 was observed according to long lasting insecticidal nets use. Taken together, the data revealed that human IgG antibody response to Anopheles gSG-P1 salivary peptide could be also used to assess human exposure to malaria vectors in Central African region. This finding strengthens the relevance of this candidate biomarker to be used for measuring human exposure to malaria vectors worldwide.
Collapse
Affiliation(s)
- Glwadys Cheteug
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Department of Microbiology and Parasitology, Faculty of Sciences, University of Buea, Buea, Cameroon
| | | | - Christiane Donkeu
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Department of Animal Biology and Physiology, Faculty of Sciences, University of Yaounde, Yaounde, Cameroon
| | - Wolfgang Ekoko
- Parasitology and Entomology Research Unit, Department of Animal Biology and Organisms, Faculty of Sciences, University of Douala, Douala, Cameroon
| | - Martine Oloume
- Department of hematology, Centre Pasteur of Cameroon, Yaoundé, Cameroon
| | - Estelle Essangui
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Parasitology and Entomology Research Unit, Department of Animal Biology and Organisms, Faculty of Sciences, University of Douala, Douala, Cameroon
| | - Philippe Nwane
- Biological Sciences Department, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon
| | - Sandrine Eveline NSango
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Laboratory of Parasitology, Mycology and Virology, Postgraduate Training Unit for Health Sciences, Postgraduate School for Pure and Applied Sciences, University of Douala, Douala, Cameroon
| | - Josiane Etang
- Biological Sciences Department, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon
- Organisation de Coordination pour la Lutte contre les Endemies en Afrique Central, Yaounde, Cameroon
| | - Samuel Wanji
- Department of Microbiology and Parasitology, Faculty of Sciences, University of Buea, Buea, Cameroon
| | - Lawrence Ayong
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
| | - Carole Else Eboumbou Moukoko
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Biological Sciences Department, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon
- Laboratory of Parasitology, Mycology and Virology, Postgraduate Training Unit for Health Sciences, Postgraduate School for Pure and Applied Sciences, University of Douala, Douala, Cameroon
- * E-mail: ,
| |
Collapse
|
24
|
Efange NM, Lobe MMM, Keumoe R, Ayong L, Efange SMN. Spirofused tetrahydroisoquinoline-oxindole hybrids as a novel class of fast acting antimalarial agents with multiple modes of action. Sci Rep 2020; 10:17932. [PMID: 33087791 PMCID: PMC7578093 DOI: 10.1038/s41598-020-74824-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 10/07/2020] [Indexed: 11/15/2022] Open
Abstract
Molecular hybridization of privileged scaffolds may generate novel antiplasmodial chemotypes that display superior biological activity and delay drug resistance. In the present study, we describe the in vitro activities and mode of action of 3′,4′-dihydro-2′H-spiro[indoline-3,1′-isoquinolin]-2-ones, a novel class of spirofused tetrahydroisoquinoline–oxindole hybrids, as novel antimalarial agents. Whole cell phenotypic screening of these compounds identified (14b), subsequently named (±)-moxiquindole, as the most potent compound in the current series with equipotent antiplasmodial activity against both chloroquine sensitive and multidrug resistant parasite strains with good selectivity. The compound was active against all asexual stages of the parasite including inhibition of merozoite egress. Additionally, (±)-moxiquindole exhibited significant inhibitory effects on hemoglobin degradation, and disrupted vacuolar lipid dynamics. Taken together, our data confirm the antiplasmodial activity of (±)-moxiquindole, and identify 3′4′-dihydro-2′H-spiro[indoline-3,1′-isoquinolin]-2-ones as a novel class of antimalarial agents with multiple modes of action.
Collapse
Affiliation(s)
- Noella M Efange
- Department of Biochemistry and Molecular Biology, University of Buea, P.O. Box 63, Buea, Cameroon.,Centre Pasteur du Cameroon, Yaoundé, Cameroon
| | - Maloba M M Lobe
- Department of Chemistry, University of Buea, P.O. Box 63, Buea, Cameroon
| | | | | | - Simon M N Efange
- Department of Chemistry, University of Buea, P.O. Box 63, Buea, Cameroon.
| |
Collapse
|
25
|
Akazong W E, Tume C, Njouom R, Ayong L, Fondoh V, Kuiate JR. Knowledge, attitude and prevalence of hepatitis B virus among healthcare workers: a cross-sectional, hospital-based study in Bamenda Health District, NWR, Cameroon. BMJ Open 2020; 10:e031075. [PMID: 32193257 PMCID: PMC7150593 DOI: 10.1136/bmjopen-2019-031075] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
INTRODUCTION Hepatitis B virus (HBV) is a bloodborne virus which can be transmitted via percutaneous and mucocutaneous exposure to infected body fluid. Healthcare workers (HCWs) who are continuously exposed to different body fluids are at an increased risk of contracting and transmitting this virus. It is thus important to evaluate the knowledge and attitude of HCWs towards HBV and the prevalence of HBV infection among them. METHODS This cross-sectional study was carried out between April and September 2017. Overall, 398 HCWs were recruited for this study. Knowledge on the route of HBV transmission and attitude towards HBV were evaluated using a well-structured questionnaire. Hepatitis B surface antigen (HBsAg) positivity was obtained using the Monolisa HBsAg ULTRA kit (Bio-Rad). Data were analysed using SPSS V.20. RESULTS Among the HCWs who participated in this study, 338 (84.9%) had heard of HBV, and 269 (67.6%) of them had adequate knowledge on the route of HBV transmission. Medical doctors were the most knowledgeable among biomedical workers and students (76.5%). The rate of stigma was highest among nurses (87, 38.8%). The prevalence of HBsAg positivity was high (42, 10.6%) given that there is an efficient and available vaccine. Overall, over 70% of HCWs invited to participate in this study responded. CONCLUSION Knowledge on the route of HBV transmission was fair, and the level of stigmatisation of HBV-infected patients and the prevalence of HBV infection were high in this study. A sensitisation campaign should be carried out to educate HCWs on HBV, thus reducing the level of stigma associated with HBV as well as the probability of contracting HBV as a nosocomial infection.
Collapse
Affiliation(s)
- Etheline Akazong W
- Department of Biochemistry, University of Dschang Faculty of Sciences, Dschang, Cameroon
| | - Christopher Tume
- Department of Biochemistry, University of Dschang Faculty of Sciences, Dschang, Cameroon
- Department of Biochemistry, University of Bamenda, Bambili, Cameroon
| | - Richard Njouom
- Virology Unit, Centre Pasteur Cameroun, Yaounde, Cameroon
| | - Lawrence Ayong
- Malaria Unit, Centre Pasteur Cameroon, Yaounde, Centre Region, Cameroon
| | - Victor Fondoh
- Laboratory, Regional Hospital Bamenda, Bamenda, North West Region, Cameroon
| | - Jules-Roger Kuiate
- Department of Biochemistry, University of Dschang Faculty of Sciences, Dschang, Cameroon
| |
Collapse
|
26
|
Kojom Foko LP, Eya'ane Meva F, Eboumbou Moukoko CE, Ntoumba AA, Ngaha Njila MI, Belle Ebanda Kedi P, Ayong L, Lehman LG. A systematic review on anti-malarial drug discovery and antiplasmodial potential of green synthesis mediated metal nanoparticles: overview, challenges and future perspectives. Malar J 2019; 18:337. [PMID: 31581943 PMCID: PMC6775654 DOI: 10.1186/s12936-019-2974-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 09/24/2019] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND The recent emergence in Southeast Asia of artemisinin resistance poses major threats to malaria control and elimination globally. Green nanotechnologies can constitute interesting tools for discovering anti-malarial medicines. This systematic review focused on the green synthesis of metal nanoparticles as potential source of new antiplasmodial drugs. METHODS Seven electronic database were used following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. RESULTS A total of 17 papers were included in the systematic review. 82.4% of the studies used plant leaves to produce nanoparticles (NPs) while three studies used microorganisms, including bacteria and fungi. Silver was the main metal precursor for the synthesis of NPs. The majority of studies obtained nanoparticles spherical in shape, with sizes ranging between 4 and 65 nm, and reported no or little cytotoxic effect of the NPs. Results based on 50% inhibitory concentration (IC50) varied between studies but, in general, could be divided into three NP categories; (i) those more effective than positive controls, (ii) those more effective than corresponding plant extracts and, (iii) those less effective than the positive controls or plant extracts. CONCLUSIONS This study highlights the high antiplasmodial potential of green-synthesized metal nanoparticles thereby underscoring the possibility to find and develop new anti-malarial drugs based on green synthesis approaches. However, the review also highlights the need for extensive in vitro and in vivo studies to confirm their safety in humans and the elucidation of the mechanism of action.
Collapse
Affiliation(s)
- Loick P Kojom Foko
- Department of Animal Biology, Faculty of Science, The University of Douala, P.O. Box 24157, Douala, Cameroon
| | - Francois Eya'ane Meva
- Department of Pharmaceutical Sciences, Faculty of Medicine and Pharmaceutical Sciences, The University of Douala, P.O. Box 2701, Douala, Cameroon.
| | - Carole E Eboumbou Moukoko
- Malaria Research Unit, Centre Pasteur Cameroon, P.O. Box 1274, Yaoundé, Cameroon
- Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, The University of Douala, P.O. Box 2701, Douala, Cameroon
| | - Agnes A Ntoumba
- Department of Animal Biology, Faculty of Science, The University of Douala, P.O. Box 24157, Douala, Cameroon
| | - Marie I Ngaha Njila
- Department of Animal Biology, Faculty of Science, The University of Douala, P.O. Box 24157, Douala, Cameroon
| | - Philippe Belle Ebanda Kedi
- Department of Animal Biology, Faculty of Science, The University of Douala, P.O. Box 24157, Douala, Cameroon
| | - Lawrence Ayong
- Malaria Research Unit, Centre Pasteur Cameroon, P.O. Box 1274, Yaoundé, Cameroon
| | - Leopold G Lehman
- Department of Animal Biology, Faculty of Science, The University of Douala, P.O. Box 24157, Douala, Cameroon.
- Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, The University of Douala, P.O. Box 2701, Douala, Cameroon.
| |
Collapse
|
27
|
Eboumbou Moukoko CE, Huang F, Nsango SE, Kojom Foko LP, Ebong SB, Epee Eboumbou P, Yan H, Sitchueng L, Garke B, Ayong L. K-13 propeller gene polymorphisms isolated between 2014 and 2017 from Cameroonian Plasmodium falciparum malaria patients. PLoS One 2019; 14:e0221895. [PMID: 31479501 PMCID: PMC6719859 DOI: 10.1371/journal.pone.0221895] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 08/16/2019] [Indexed: 12/23/2022] Open
Abstract
The emergence of artemisinin-resistant parasites since the late 2000s at the border of Cambodia and Thailand poses serious threats to malaria control globally, particularly in Africa which bears the highest malaria transmission burden. This study aimed to obtain reliable data on the current state of the kelch13 molecular marker for artemisinin resistance in Plasmodium falciparum in Cameroon. DNA was extracted from the dried blood spots collected from epidemiologically distinct endemic areas in the Center, Littoral and North regions of Cameroon. Nested PCR products from the Kelch13-propeller gene were sequenced and analyzed on an ABI 3730XL automatic sequencer. Of 219 dried blood spots, 175 were sequenced successfully. We identified six K13 mutations in 2.9% (5/175) of samples, including 2 non-synonymous, the V589I allele had been reported in Africa already and one new allele E612K had not been reported yet. These two non-synonymous mutations were uniquely found in parasites from the Littoral region. One sample showed two synonymous mutations within the kelch13 gene. We also observed two infected samples with mixed K13 mutant and K13 wild-type infection. Taken together, our data suggested the circulation of the non-synonymous K13 mutations in Cameroon. Albeit no mutations known to be associated with parasite clearance delays in the study population, there is need for continuous surveillance for earlier detection of resistance as long as ACTs are used and scaled up in the community.
Collapse
Affiliation(s)
- Carole Else Eboumbou Moukoko
- Biological Sciences Department, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon
- Malaria Research Unit, Centre Pasteur Cameroon, Yaoundé, Cameroon
- * E-mail: , (CEEM); (FH)
| | - Fang Huang
- Malarial Department, National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China
- * E-mail: , (CEEM); (FH)
| | - Sandrine Eveline Nsango
- Biological Sciences Department, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon
- Malaria Research Unit, Centre Pasteur Cameroon, Yaoundé, Cameroon
| | - Loic Pradel Kojom Foko
- Parasitology and Entomology Research Unit, Department of Animal Organisms, Faculty of Science, University of Douala, Douala, Cameroon
| | - Serge Bruno Ebong
- Animal Organisms Biology and Physiology Department, Faculty of Sciences, University of Douala, Douala, Cameroon
| | | | - He Yan
- Malarial Department, National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China
| | - Livia Sitchueng
- Malaria Research Unit, Centre Pasteur Cameroon, Yaoundé, Cameroon
| | - Bouba Garke
- Centre Pasteur Cameroon, Garoua Center, Yaoundé, Cameroon
| | - Lawrence Ayong
- Malaria Research Unit, Centre Pasteur Cameroon, Yaoundé, Cameroon
| |
Collapse
|
28
|
Essangui E, Eboumbou Moukoko CE, Nguedia N, Tchokwansi M, Banlanjo U, Maloba F, Fogang B, Donkeu C, Biabi M, Cheteug G, Kemleu S, Elanga-Ndille E, Lehman L, Ayong L. Demographical, hematological and serological risk factors for Plasmodium falciparum gametocyte carriage in a high stable transmission zone in Cameroon. PLoS One 2019; 14:e0216133. [PMID: 31022294 PMCID: PMC6483257 DOI: 10.1371/journal.pone.0216133] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 04/15/2019] [Indexed: 01/22/2023] Open
Abstract
Presence of mature gametocyte forms of malaria parasites in peripheral blood is a key requirement for malaria transmission. Yet, studies conducted in most malaria transmission zones report the absence of gametocyte in the majority of patients. We therefore sought to determine the risk factors of both all-stage and mature gametocyte carriage in an area with high stable transmission of Plasmodium falciparum in Cameroon. Gametocyte positivity was determined using three complementary methods: thick blood smear microscopy, RT-PCR and RT-LAMP, whereas exposure to the infection was assessed by enzyme-linked immunosorbent assay. Of 361 malaria endemic residents randomly included in the study (mean age: 28±23 years, age range: 2–100 years, male/female sex ratio: 1.1), 87.8% were diagnosed with P. falciparum infection, of whom 45.7% presented with fever (axillary body temperature ≥37.5°C). Mature gametocyte positivity was 1.9% by thick blood smear microscopy and 8.9% by RT-PCR targeting the mature gametocyte transcript, Pfs25. The gametocyte positivity rate was 24.1% and 36.3% by RT-PCR or RT-LAMP, respectively, when targeting the sexual stage marker, Pfs16. Multivariate analyses revealed anemia as a common independent risk factor for both mature and all-stage gametocyte carriage, whereas fever and low anti-gametocyte antibody levels were independently associated with all-stage gametocyte carriage only. Taken together, the data suggest important differences in risk factors of gametocyte carriage depending on stage analyzed, with anemia, fever and low antiplasmodial plasma antibody levels representing the major contributing risk factors.
Collapse
Affiliation(s)
- Estelle Essangui
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Faculty of Sciences, University of Douala, Douala, Cameroon
| | - Carole Else Eboumbou Moukoko
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon
| | - Niels Nguedia
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
| | | | - Umaru Banlanjo
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
| | - Franklin Maloba
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Faculty of Sciences, University of Buea, Buea, Cameroon
| | - Balotin Fogang
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Faculty of Sciences, University of Yaounde, Yaounde, Cameroon
| | - Christiane Donkeu
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Faculty of Sciences, University of Yaounde, Yaounde, Cameroon
| | - Marie Biabi
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Faculty of Sciences, University of Douala, Douala, Cameroon
| | - Glwadys Cheteug
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Faculty of Sciences, University of Buea, Buea, Cameroon
| | - Sylvie Kemleu
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Faculty of Health Sciences, University of Buea, Buea, Cameroon
| | - Emmanuel Elanga-Ndille
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Centre for Research in Infectious Diseases, Yaounde, Cameroon
| | - Léopold Lehman
- Faculty of Sciences, University of Douala, Douala, Cameroon
| | - Lawrence Ayong
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- * E-mail:
| |
Collapse
|
29
|
Maffo CN, Berry A, Morlais I, B Feufack Donfack L, Bayibeki Ngano A, E Nsango S, Milo Sarah-Matio E, Ayong L. PO 8290 INFLUENCE OF THE SICKLE CELL TRAIT ON PLASMODIUM FALCIPARUM TRANSMISSION IN ASYMPTOMATIC CHILDREN. BMJ Glob Health 2019. [DOI: 10.1136/bmjgh-2019-edc.69] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
BackgroundThe sickle cell trait is associated with protection against severe malaria. Recently, it has been shown that the genetic protection conferred by the sickle cell trait has no effect on the transmission of Plasmodium species from humans to vectors. Our study aimed to investigate the putative association between the sickle cell trait AS and the susceptibility to malaria infection of both the human host and the insect vector.MethodsThe study was conducted from June to November 2017 among asymptomatic children living in Cameroon. The samples were collected on microscopy slides, Whatman FTA and grade 17 paper for the selection of gametocyte carriers by microscopy, the molecular diagnosis of Plasmodium species, and sickle cell trait (PCR- RFLP), respectively. Infectivity of the mosquito was measured by experimental infections on gametocyte-containing blood from naturally infected carrier. Genetic diversity was measured using microsatellite markers.ResultsA total of 1557 children were recruited; the prevalence of Plasmodium infection among this group was 58% and the AS sickle cell trait 20%. No significant difference in the prevalence of P. falciparum infection was observed according to the sickle cell trait carriage and this irrespective of the parasite stage (p>0.05). The level of infectivity of the mosquito was higher when feedings were performed on blood from HbAS genotypes compared to HbAA genotype blood, and the difference was even more significant when the blood pellet was resuspended with non-immune AB plasma (p<0.0001). No significant difference was observed in the infection complexity between HbAS and HbAA genotypes (p>0.05).ConclusionPlasmodium infection is not influenced by HbAS genotype regardless of parasite stage; the risk of anopheles infection is higher with blood from gametocyte carriers with sickle cell trait (HbAS). The sickle cell trait does not affect the multiplicity of infection.
Collapse
|
30
|
Fogang B, Djontu JC, Megnekou R, Ayong L. PO 8289 ASSOCIATION BETWEEN PLASMA LEVELS OF IL-27, IL-6 CYTOKINES AND P. FALCIPARUM INFECTION IN PREGNANT WOMEN LIVING IN MBALMAYO, CAMEROON. BMJ Glob Health 2019. [DOI: 10.1136/bmjgh-2019-edc.68] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
BackgroundThe appropriate balance between anti-inflammatory and pro-inflammatory cytokines is necessary for protection against pregnancy-associated malaria and poor pregnancy outcomes. This study therefore aims to investigate the relationship between plasma levels of some regulatory cytokines and P. falciparum infection in Cameroonian women during pregnancy.MethodsPeripheral blood was collected from 131 women during pregnancy and 27 non-pregnant women living in the Mbalmayo area between May and December 2014. Parasitaemia was determined by microscopy and haemoglobin level using a haematological counter. Plasma levels of IL-27 and IL-6 cytokines were measured using the Magnetic Luminex Screening Assay technique.ResultsParasitaemia associated negatively with haemoglobin level (rs=–0.43; p<0.001). The plasma level of IL-6 was higher in pregnant women than in non-pregnant women (p=0.05). Regarding parasitaemia, plasma level of IL-27 was significantly higher in non-infected than in infected women (p=0.028) while that of IL-6 was significantly higher in infected women (p<0.0001). Moreover, parasitaemia correlated negatively with the plasma level of IL-27 (p=0.034) and positively with that of IL-6 (p<0.0001). In addition, level of IL-6 was significantly higher in anaemia-positive than in anaemia-negative women (p=0.028). On the other hand, level of IL-27 negatively associated with the parity (p=0.022) and gestation age (p=0.014).ConclusionThese results show that in pregnant women, P. falciparum malaria infection is associated with high plasma level of IL-6 and low level of IL-27, suggesting that IL-27 could have a protective effect against pregnancy-associated malaria while IL-6 seem to be a potential biomarker of the disease.
Collapse
|
31
|
Kemleu S, Guelig D, Eboumbou Moukoko C, Essangui E, Diesburg S, Mouliom A, Melingui B, Manga J, Donkeu C, Epote A, Texier G, LaBarre P, Burton R, Ayong L. A Field-Tailored Reverse Transcription Loop-Mediated Isothermal Assay for High Sensitivity Detection of Plasmodium falciparum Infections. PLoS One 2016; 11:e0165506. [PMID: 27824866 PMCID: PMC5100904 DOI: 10.1371/journal.pone.0165506] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 10/13/2016] [Indexed: 11/19/2022] Open
Abstract
Highly sensitive and field deployable molecular diagnostic tools are critically needed for detecting submicroscopic, yet transmissible levels of malaria parasites prevalent in malaria endemic countries worldwide. A reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed and evaluated in comparison with thick blood smear microscopy, an antigen-based rapid diagnostic test (RDT), and an in-house RT-PCR targeting the same RT-LAMP transcript. The optimized assay detected Plasmodium falciparum infections in as little as 0.25ng of total parasite RNA, and exhibited a detection limit of 0.08 parasites/ μL when tested directly on infected whole blood lysates, or ~0.0008 parasites/ μL when using RNA extracts. Assay positivity was observed as early as eight minutes from initiation of the RT-LAMP and in most cases the reaction was complete before twenty minutes. Clinical evaluation of the assay on 132 suspected malaria cases resulted in a positivity rate of 90% for RT-LAMP using extracted RNA, and 85% when using whole blood lysates. The positivity rates were 70% for P. falciparum-specific RDT, 83% for RT-PCR, and 74% for thick blood smear microscopy (Mean parasite density = 36,986 parasites/ μL). Concordance rates between the developed RT-LAMP and comparator tests were greater than 75%, the lowest being with light microscopy (78%, McNemar's test: P = 0.0002), and the highest was with RT-PCR (87%, McNemar's test: P = 0.0523). Compared to reference RT-PCR, assay sensitivity was 90% for RT-LAMP on whole blood, and 96% for RT-LAMP using corresponding RNA extracts. Electricity-free heaters were further developed and evaluated in comparison with a battery-operated isothermal amplification machine for use with the developed test in resource-limited settings. Taken together, the data highlight the benefits of targeting high abundant RNA transcripts in molecular diagnosis, as well as the potential usefulness of the developed RT-LAMP-assay in malaria diagnosis in low to high parasite density settings.
Collapse
Affiliation(s)
- Sylvie Kemleu
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroon
| | - Dylan Guelig
- PATH, Seattle, Washington, United States of America
| | - Carole Eboumbou Moukoko
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroon
- Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon
| | - Estelle Essangui
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroon
- Faculty of Sciences, University of Douala, Douala, Cameroon
| | | | - Abas Mouliom
- Hematology Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroon
| | | | - Jeanne Manga
- Hematology Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroon
| | - Christiane Donkeu
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroon
| | - Annie Epote
- Hematology Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroon
| | - Gaëtan Texier
- Public Health & Epidemiology Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroon
| | - Paul LaBarre
- PATH, Seattle, Washington, United States of America
| | | | - Lawrence Ayong
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroon
- * E-mail:
| |
Collapse
|
32
|
Roberts BF, Iyamu ID, Lee S, Lee E, Ayong L, Kyle DE, Yuan Y, Manetsch R, Chakrabarti D. Spirocyclic chromanes exhibit antiplasmodial activities and inhibit all intraerythrocytic life cycle stages. Int J Parasitol Drugs Drug Resist 2016; 6:85-92. [PMID: 27054067 PMCID: PMC4805781 DOI: 10.1016/j.ijpddr.2016.02.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 01/28/2016] [Accepted: 02/09/2016] [Indexed: 11/27/2022]
Abstract
We screened a collection of synthetic compounds consisting of natural-product-like substructural motifs to identify a spirocyclic chromane as a novel antiplasmodial pharmacophore using an unbiased cell-based assay. The most active spirocyclic compound UCF 201 exhibits a 50% effective concentration (EC50) of 350 nM against the chloroquine-resistant Dd2 strain and a selectivity over 50 using human liver HepG2 cells. Our analyses of physicochemical properties of UCF 201 showed that it is in compliance with Lipinski's parameters and has an acceptable physicochemical profile. We have performed a limited structure-activity-relationship study with commercially available chromanes preserving the spirocyclic motif. Our evaluation of stage specificities of UCF 201 indicated that the compound is early-acting in blocking parasite development at ring, trophozoite and schizont stages of development as well as merozoite invasion. SPC is an attractive lead candidate scaffold because of its ability to act on all stages of parasite's aexual life cycle unlike current antimalarials. SPC is a novel antiplasmodial scaffold. SPC has an EC50 of 350 nM against chloroquine-resistant parasite and is selective. SPC inhibits all stages of parasite growth in erythrocytes.
Collapse
Affiliation(s)
- Bracken F Roberts
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, USA
| | - Iredia D Iyamu
- Department of Chemistry and Chemical Biology and Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, USA
| | - Sukjun Lee
- Institut Pasteur Korea, Seongnam-si, Gyeonggi-do, Republic of Korea
| | - Eunyoung Lee
- Institut Pasteur Korea, Seongnam-si, Gyeonggi-do, Republic of Korea
| | - Lawrence Ayong
- Institut Pasteur Korea, Seongnam-si, Gyeonggi-do, Republic of Korea
| | - Dennis E Kyle
- Department of Global Health, College of Public Health, University of South Florida, Tampa, FL, USA
| | - Yu Yuan
- Department of Chemistry, University of Central Florida, Orlando, FL, USA
| | - Roman Manetsch
- Department of Chemistry and Chemical Biology and Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, USA
| | - Debopam Chakrabarti
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, USA.
| |
Collapse
|
33
|
Lee S, Lim D, Lee E, Lee N, Lee HG, Cechetto J, Liuzzi M, Freitas-Junior LH, Song JS, Bae MA, Oh S, Ayong L, Park SB. Discovery of Carbohybrid-Based 2-Aminopyrimidine Analogues As a New Class of Rapid-Acting Antimalarial Agents Using Image-Based Cytological Profiling Assay. J Med Chem 2014; 57:7425-34. [DOI: 10.1021/jm5009693] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sukjun Lee
- Early
Discovery Program, Institut Pasteur Korea, Seongnam-si, Gyeonggi-do 463-400, Korea
| | - Donghyun Lim
- WCU
Department of Biophysics and Chemical Biology, Seoul National University, San 56-1, Shilim-dong, Gwanak-gu, Seoul 151-747, Korea
| | - Eunyoung Lee
- Early
Discovery Program, Institut Pasteur Korea, Seongnam-si, Gyeonggi-do 463-400, Korea
| | - Nakyung Lee
- Center
for Neglected Diseases Drug Discovery (CND3), Institut Pasteur Korea, Seongnam-si, Gyeonggi-do 463-400, Korea
| | - Hong-gun Lee
- Center
for Core Technologies, Institut Pasteur Korea, Seongnam-si, Gyeonggi-do 463-400, Korea
| | - Jonathan Cechetto
- Center
for Core Technologies, Institut Pasteur Korea, Seongnam-si, Gyeonggi-do 463-400, Korea
| | - Michel Liuzzi
- Early
Discovery Program, Institut Pasteur Korea, Seongnam-si, Gyeonggi-do 463-400, Korea
| | - Lucio H. Freitas-Junior
- Center
for Neglected Diseases Drug Discovery (CND3), Institut Pasteur Korea, Seongnam-si, Gyeonggi-do 463-400, Korea
| | - Jin Sook Song
- Drug
Discovery Platform Technology Group, Drug Discovery Division, Korea Research Institute of Chemical Technology, Daejeon 305-600, Korea
| | - Myung Ae Bae
- Drug
Discovery Platform Technology Group, Drug Discovery Division, Korea Research Institute of Chemical Technology, Daejeon 305-600, Korea
| | - Sangmi Oh
- Medicinal
Chemistry and Chemical Biology Group, Institut Pasteur Korea, Seongnam-si, Gyeonggi-do 463-400, Korea
| | - Lawrence Ayong
- Early
Discovery Program, Institut Pasteur Korea, Seongnam-si, Gyeonggi-do 463-400, Korea
| | - Seung Bum Park
- WCU
Department of Biophysics and Chemical Biology, Seoul National University, San 56-1, Shilim-dong, Gwanak-gu, Seoul 151-747, Korea
- Department
of Chemistry, Seoul National University, Seoul 151-747, Korea
| |
Collapse
|
34
|
Moon S, Lee S, Kim H, Freitas-Junior LH, Kang M, Ayong L, Hansen MAE. An image analysis algorithm for malaria parasite stage classification and viability quantification. PLoS One 2013; 8:e61812. [PMID: 23626733 PMCID: PMC3634010 DOI: 10.1371/journal.pone.0061812] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Accepted: 03/13/2013] [Indexed: 11/23/2022] Open
Abstract
With more than 40% of the world’s population at risk, 200–300 million infections each year, and an estimated 1.2 million deaths annually, malaria remains one of the most important public health problems of mankind today. With the propensity of malaria parasites to rapidly develop resistance to newly developed therapies, and the recent failures of artemisinin-based drugs in Southeast Asia, there is an urgent need for new antimalarial compounds with novel mechanisms of action to be developed against multidrug resistant malaria. We present here a novel image analysis algorithm for the quantitative detection and classification of Plasmodium lifecycle stages in culture as well as discriminating between viable and dead parasites in drug-treated samples. This new algorithm reliably estimates the number of red blood cells (isolated or clustered) per fluorescence image field, and accurately identifies parasitized erythrocytes on the basis of high intensity DAPI-stained parasite nuclei spots and Mitotracker-stained mitochondrial in viable parasites. We validated the performance of the algorithm by manual counting of the infected and non-infected red blood cells in multiple image fields, and the quantitative analyses of the different parasite stages (early rings, rings, trophozoites, schizonts) at various time-point post-merozoite invasion, in tightly synchronized cultures. Additionally, the developed algorithm provided parasitological effective concentration 50 (EC50) values for both chloroquine and artemisinin, that were similar to known growth inhibitory EC50 values for these compounds as determined using conventional SYBR Green I and lactate dehydrogenase-based assays.
Collapse
Affiliation(s)
- Seunghyun Moon
- Image Mining (IM) Group, Institut Pasteur Korea, Seongnam-si, Gyeonggi-do, South Korea
- Department of Mathematics, Seoul National University (SNU), Gwanak-Gu, Seoul, South Korea
| | - Sukjun Lee
- Malaria Drug Discovery (MRA) Unit, Institut Pasteur Korea, Seongnam-si, Gyeonggi-do, South Korea
| | - Heechang Kim
- Image Mining (IM) Group, Institut Pasteur Korea, Seongnam-si, Gyeonggi-do, South Korea
| | - Lucio H. Freitas-Junior
- Center for Neglected Diseases (CND3), Institut Pasteur Korea, Seongnam-si, Gyeonggi-do, South Korea
| | - Myungjoo Kang
- Department of Mathematics, Seoul National University (SNU), Gwanak-Gu, Seoul, South Korea
| | - Lawrence Ayong
- Malaria Drug Discovery (MRA) Unit, Institut Pasteur Korea, Seongnam-si, Gyeonggi-do, South Korea
| | - Michael A. E. Hansen
- Image Mining (IM) Group, Institut Pasteur Korea, Seongnam-si, Gyeonggi-do, South Korea
- * E-mail:
| |
Collapse
|
35
|
Zhang Y, Zhu W, Liu YL, Wang H, Wang K, Li K, No JH, Ayong L, Gulati A, Pang R, Freitas-Junior L, Morita CT, Oldfield E. Chemo-Immunotherapeutic Anti-Malarials Targeting Isoprenoid Biosynthesis. ACS Med Chem Lett 2013; 4:423-427. [PMID: 23610597 DOI: 10.1021/ml4000436] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
We synthesized 30 lipophilic bisphosphonates and tested them in malaria parasite killing (targeting parasite geranylgeranyl diphosphate synthase, GGPPS) as well in human γδ T cell activation (targeting human farnesyl diphosphate synthase, FPPS). Similar patterns of activity were seen in inhibiting human FPPS and Plasmodium GGPPS, with short to medium chain-length species having most activity. In cells, shorter chain-length species had low activity, due to poor membrane permeability, and longer chain length species were poor enzyme inhibitors. Optimal activity was thus seen with ~C10 side-chains, which have the best combination of enzyme inhibition and cell penetration. We also solved the crystal structure of one potent inhibitor, bound to FPPS. The results are of interest since they suggest the possibility of a combined chemo/immuno-therapeutic approach to anti-malarial development in which both direct parasite killing as well as γδ T cell activation can be achieved with a single compound.
Collapse
Affiliation(s)
- Yonghui Zhang
- PrenylX Research Institute, Zhangjiagang 215600, People’s Republic
of China
| | | | | | - Hong Wang
- Division of Immunology, Department
of Internal Medicine, the Interdisciplinary Graduate Program in Immunology, University of Iowa Carver College of Medicine, Veterans
Affairs Health Care System, Iowa City, Iowa 52242, United States
| | | | | | - Joo Hwan No
- Center for Neglected Diseases Drug
Discovery, Institute Pasteur Korea, Seongnam-si,
Gyeonggi-do 463-400, South Korea
| | - Lawrence Ayong
- Center for Neglected Diseases Drug
Discovery, Institute Pasteur Korea, Seongnam-si,
Gyeonggi-do 463-400, South Korea
| | | | | | - Lucio Freitas-Junior
- Center for Neglected Diseases Drug
Discovery, Institute Pasteur Korea, Seongnam-si,
Gyeonggi-do 463-400, South Korea
| | - Craig T. Morita
- Division of Immunology, Department
of Internal Medicine, the Interdisciplinary Graduate Program in Immunology, University of Iowa Carver College of Medicine, Veterans
Affairs Health Care System, Iowa City, Iowa 52242, United States
| | | |
Collapse
|
36
|
Ku MJ, Dossin FDM, Hansen MAE, Genovesio A, Ayong L, Freitas-Junior LH. An image-based drug susceptibility assay targeting the placental sequestration of Plasmodium falciparum-infected erythrocytes. PLoS One 2012; 7:e41765. [PMID: 22952585 PMCID: PMC3430655 DOI: 10.1371/journal.pone.0041765] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Accepted: 06/27/2012] [Indexed: 11/19/2022] Open
Abstract
Placental malaria is a significant cause of all malaria-related deaths globally for which no drugs have been developed to specifically disrupt its pathogenesis. To facilitate the discovery of antimalarial drugs targeting the cytoadherence process of Plasmodium-infected erythrocytes in the placenta microvasculature, we have developed an automated image-based assay for high-throughput screening for potent cytoadherence inhibitors in vitro. Parasitized erythrocytes were drug-treated for 24 h and then allowed to adhere on a monolayer of placental BeWo cells prior to red blood cell staining with glycophorin A antibodies. Upon image-acquisition, drug effects were quantified as the proportion of treated parasitized erythrocytes to BeWo cells compared to the binding of untreated iRBCs. We confirmed the reliability of this new assay by comparing the binding ratios of CSA- and CD36-panned parasites on the placental BeWo cells, and by quantifying the effects of chondroitin sulfate A, brefeldin A, and artemisinin on the binding. By simultaneously examining the drug effects on parasite viability, we could discriminate between cytoadherence-specific inhibitors and other schizonticidal compounds. Taken together, our data establish that the developed assay is highly suitable for drug studies targeting placental malaria, and will facilitate the discovery and rapid development of new therapies against malaria.
Collapse
Affiliation(s)
- Min-Je Ku
- Center for Neglected Diseases Drug Discovery (CND3), Institut Pasteur Korea, Seongnam-si, Gyeonggi-do, South Korea
| | - Fernando de M. Dossin
- Center for Neglected Diseases Drug Discovery (CND3), Institut Pasteur Korea, Seongnam-si, Gyeonggi-do, South Korea
| | - Michael A. E. Hansen
- Center for Core Technologies-Image Mining, Institut Pasteur Korea, Seongnam-si, Gyeonggi-do, South Korea
| | - Auguste Genovesio
- Center for Core Technologies-Image Mining, Institut Pasteur Korea, Seongnam-si, Gyeonggi-do, South Korea
| | - Lawrence Ayong
- Center for Neglected Diseases Drug Discovery (CND3), Institut Pasteur Korea, Seongnam-si, Gyeonggi-do, South Korea
| | - Lucio H. Freitas-Junior
- Center for Neglected Diseases Drug Discovery (CND3), Institut Pasteur Korea, Seongnam-si, Gyeonggi-do, South Korea
- * E-mail:
| |
Collapse
|
37
|
Ayong L, DaSilva T, Mauser J, Allen CM, Chakrabarti D. Evidence for prenylation-dependent targeting of a Ykt6 SNARE in Plasmodium falciparum. Mol Biochem Parasitol 2011; 175:162-8. [DOI: 10.1016/j.molbiopara.2010.11.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Revised: 11/01/2010] [Accepted: 11/05/2010] [Indexed: 10/18/2022]
|
38
|
Rooney PJ, Ayong L, Tobin CM, Moreno SNJ, Knoll LJ. TgVTC2 is involved in polyphosphate accumulation in Toxoplasma gondii. Mol Biochem Parasitol 2010; 176:121-6. [PMID: 21195114 DOI: 10.1016/j.molbiopara.2010.12.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2010] [Revised: 12/20/2010] [Accepted: 12/22/2010] [Indexed: 10/18/2022]
Abstract
Polyphosphate is found in every cell, having roles in diverse processes, including differentiation and response to stress. In this study, we characterize a Toxoplasma gondii mutant containing an insertion within the carboxy-terminal end of a homolog of Saccharomyces cerevisiae Vtc2p, a component of the polyphosphate synthetic machinery. Locus TgVTC2 encodes a 140kDa protein containing conserved SPX, VTC and transmembrane domains. TgVTC2 localizes in punctate spots within the cytoplasm that do not co-localize with known markers. The TgVTC2 mutant showed dramatically reduced polyphosphate accumulation, a defect restored by introduction of TgVTC2 to the mutant. Insertion within TgVTC2 resulted in increased transcript levels for two loci, including a putative FIKK kinase. These transcript levels were restored to wild-type levels upon complementation with the TgVTC2 locus. The TgVTC2 locus was refractory to knockout, and may be essential. Analysis of this TgVTC2 mutant will facilitate dissection of the T. gondii polyphosphate synthesis pathway.
Collapse
Affiliation(s)
- Peggy J Rooney
- Department of Medical Microbiology and Immunology, University of Wisconsin School of Medicine and Public Health, Microbial Sciences Building Room 3345, 1550 Linden Drive, Madison, WI 53706, USA
| | | | | | | | | |
Collapse
|
39
|
Ayong L, Pagnotti G, Tobon AB, Chakrabarti D. Identification of Plasmodium falciparum family of SNAREs. Mol Biochem Parasitol 2007; 152:113-22. [PMID: 17240462 DOI: 10.1016/j.molbiopara.2006.12.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2006] [Revised: 12/13/2006] [Accepted: 12/14/2006] [Indexed: 10/23/2022]
Abstract
SNARE proteins function as specificity determinants in all eukaryotic vesicle-mediated transport pathways. Although the intra-erythrocytic parasite Plasmodium falciparum is known to target nuclear-encoded proteins via transport vesicles to several destinations within and beyond its plasma membrane, little is known about the role of SNARE proteins in these unusual trafficking pathways. In this study, we identified and compared the subunit structure of P. falciparum homologues of SNAREs (PfSNAREs) with their complements in mammals, and determined the subcellular localizations of some family members. A comprehensive bioinformatics analysis of the P. falciparum genome revealed 18 SNARE-like proteins that could be classified into five main phylogenetic groups: membrin-like, Bet1-like, VAMP-like, syntaxin5-like, and a P. falciparum-specific syntaxin-like subfamily. Unique to some PfSNARE proteins were presence of atypical amino acid residues at the "0" layer position, presence of up to two transmembrane segments, and frequent occurrence of low-complexity regions. Subcellular distribution of green fluorescence protein (GFP)-tagged P. falciparum SNARE orthologues indicates that PfSyn5p and PfSec22p are partly associated to ER and Golgi compartments, and to other punctuated structures within the parasite plasma membrane. Our data confirms of a conserved SNARE-mediated anterograde transport system in the parasite and argues against any involvement of these two SNAREs in vesicular trafficking within the host cell compartment.
Collapse
Affiliation(s)
- Lawrence Ayong
- Department of Molecular Biology & Microbiology, University of Central Florida, Orlando, FL 32826, United States
| | | | | | | |
Collapse
|