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Abera A, Mamecha T, Abose E, Bokicho B, Ashole A, Bishaw T, Mariyo A, Bogale B, Terefe H, Tadesse H, Belachew M, Difabachew H, Eukubay A, Kinde S, Ali A, Regasa F, Seife F, Kebede Z, Wossen M, Tollera G, Hailu M, Manaye N, Van Reet N, Priotto G, van Griensven J, Pareyn M, Tasew G. Reemergence of Human African Trypanosomiasis Caused by Trypanosoma brucei rhodesiense, Ethiopia. Emerg Infect Dis 2024; 30:125-128. [PMID: 37967521 PMCID: PMC10756368 DOI: 10.3201/eid3001.231319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2023] Open
Abstract
We report 4 cases of human African trypanosomiasis that occurred in Ethiopia in 2022, thirty years after the last previously reported case in the country. Two of 4 patients died before medicine became available. We identified the infecting parasite as Trypanosoma brucei rhodesiense. Those cases imply human African trypanosomiasis has reemerged.
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Morrison LJ, Steketee PC, Tettey MD, Matthews KR. Pathogenicity and virulence of African trypanosomes: From laboratory models to clinically relevant hosts. Virulence 2023; 14:2150445. [PMID: 36419235 DOI: 10.1080/21505594.2022.2150445] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
African trypanosomes are vector-borne protozoa, which cause significant human and animal disease across sub-Saharan Africa, and animal disease across Asia and South America. In humans, infection is caused by variants of Trypanosoma brucei, and is characterized by varying rate of progression to neurological disease, caused by parasites exiting the vasculature and entering the brain. Animal disease is caused by multiple species of trypanosome, primarily T. congolense, T. vivax, and T. brucei. These trypanosomes also infect multiple species of mammalian host, and this complexity of trypanosome and host diversity is reflected in the spectrum of severity of disease in animal trypanosomiasis, ranging from hyperacute infections associated with mortality to long-term chronic infections, and is also a main reason why designing interventions for animal trypanosomiasis is so challenging. In this review, we will provide an overview of the current understanding of trypanosome determinants of infection progression and severity, covering laboratory models of disease, as well as human and livestock disease. We will also highlight gaps in knowledge and capabilities, which represent opportunities to both further our fundamental understanding of how trypanosomes cause disease, as well as facilitating the development of the novel interventions that are so badly needed to reduce the burden of disease caused by these important pathogens.
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Affiliation(s)
- Liam J Morrison
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian, UK
| | - Pieter C Steketee
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian, UK
| | - Mabel D Tettey
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Keith R Matthews
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
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Possart K, Herrmann FC, Jose J, Schmidt TJ. In Silico and In Vitro Search for Dual Inhibitors of the Trypanosoma brucei and Leishmania major Pteridine Reductase 1 and Dihydrofolate Reductase. Molecules 2023; 28:7526. [PMID: 38005256 PMCID: PMC10673058 DOI: 10.3390/molecules28227526] [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: 09/27/2023] [Revised: 11/06/2023] [Accepted: 11/07/2023] [Indexed: 11/26/2023] Open
Abstract
The parasites Trypanosoma brucei (Tb) and Leishmania major (Lm) cause the tropical diseases sleeping sickness, nagana, and cutaneous leishmaniasis. Every year, millions of humans, as well as animals, living in tropical to subtropical climates fall victim to these illnesses' health threats. The parasites' frequent drug resistance and widely spread natural reservoirs heavily impede disease prevention and treatment. Due to pteridine auxotrophy, trypanosomatid parasites have developed a peculiar enzyme system consisting of dihydrofolate reductase-thymidylate synthase (DHFR-TS) and pteridine reductase 1 (PTR1) to support cell survival. Extending our previous studies, we conducted a comparative study of the T. brucei (TbDHFR, TbPTR1) and L. major (LmDHFR, LmPTR1) enzymes to identify lead structures with a dual inhibitory effect. A pharmacophore-based in silico screening of three natural product databases (approximately 4880 compounds) was performed to preselect possible inhibitors. Building on the in silico results, the inhibitory potential of promising compounds was verified in vitro against the recombinant DHFR and PTR1 of both parasites using spectrophotometric enzyme assays. Twelve compounds were identified as dual inhibitors against the Tb enzymes (0.2 μM < IC50 < 85.1 μM) and ten against the respective Lm enzymes (0.6 μM < IC50 < 84.5 μM). These highly promising results may represent the starting point for the future development of new leads and drugs utilizing the trypanosomatid pteridine metabolism as a target.
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Affiliation(s)
- Katharina Possart
- University of Muenster, Institute for Pharmaceutical Biology and Phytochemistry (IPBP), PharmaCampus, Corrensstrasse 48, D-48149 Muenster, Germany; (K.P.); (F.C.H.)
| | - Fabian C. Herrmann
- University of Muenster, Institute for Pharmaceutical Biology and Phytochemistry (IPBP), PharmaCampus, Corrensstrasse 48, D-48149 Muenster, Germany; (K.P.); (F.C.H.)
| | - Joachim Jose
- University of Muenster, Institute of Pharmaceutical and Medicinal Chemistry, PharmaCampus, Corrensstrasse 48, D-48149 Muenster, Germany;
| | - Thomas J. Schmidt
- University of Muenster, Institute for Pharmaceutical Biology and Phytochemistry (IPBP), PharmaCampus, Corrensstrasse 48, D-48149 Muenster, Germany; (K.P.); (F.C.H.)
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4
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Monti L, Liu LJ, Varricchio C, Lucero B, Alle T, Yang W, Bem-Shalom I, Gilson M, Brunden KR, Brancale A, Caffrey CR, Ballatore C. Structure-Activity Relationships, Tolerability and Efficacy of Microtubule-Active 1,2,4-Triazolo[1,5-a]pyrimidines as Potential Candidates to Treat Human African Trypanosomiasis. ChemMedChem 2023; 18:e202300193. [PMID: 37429821 PMCID: PMC10615688 DOI: 10.1002/cmdc.202300193] [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: 04/08/2023] [Revised: 07/08/2023] [Accepted: 07/10/2023] [Indexed: 07/12/2023]
Abstract
Tubulin and microtubules (MTs) are potential protein targets to treat parasitic infections and our previous studies have shown that the triazolopyrimidine (TPD) class of MT-active compounds hold promise as antitrypanosomal agents. MT-targeting TPDs include structurally related but functionally diverse congeners that interact with mammalian tubulin at either one or two distinct interfacial binding sites; namely, the seventh and vinca sites, which are found within or between α,β-tubulin heterodimers, respectively. Evaluation of the activity of 123 TPD congeners against cultured Trypanosoma brucei enabled a robust quantitative structure-activity relationship (QSAR) model and the prioritization of two congeners for in vivo pharmacokinetics (PK), tolerability and efficacy studies. Treatment of T. brucei-infected mice with tolerable doses of TPDs significantly decreased blood parasitemia within 24 h. Further, two once-weekly doses at 10 mg/kg of a candidate TPD significantly extended the survival of infected mice relative to infected animals treated with vehicle. Further optimization of dosing and/or the dosing schedule of these CNS-active TPDs may provide alternative treatments for human African trypanosomiasis.
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Affiliation(s)
- Ludovica Monti
- Center for Discovery and Innovation in Parasitic Diseases (CDIPD), Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, 92093, La Jolla, CA, USA
- Present affiliation: Chemistry Department, Molecular Sciences Research Hub, Imperial College London, 82 Wood Lane, W12 0BZ, London, UK
| | - Lawrence J Liu
- Center for Discovery and Innovation in Parasitic Diseases (CDIPD), Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, 92093, La Jolla, CA, USA
| | - Carmine Varricchio
- Cardiff School of Pharmacy and Pharmaceutical Sciences, Cardiff University, CF103NB, Cardiff, UK
| | - Bobby Lucero
- Center for Discovery and Innovation in Parasitic Diseases (CDIPD), Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, 92093, La Jolla, CA, USA
- Department of Chemistry & Biochemistry, University of California, San Diego, 9500 Gilman Drive, 92093, La Jolla, CA, USA
| | - Thibault Alle
- Center for Discovery and Innovation in Parasitic Diseases (CDIPD), Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, 92093, La Jolla, CA, USA
| | - Wenqian Yang
- Center for Discovery and Innovation in Parasitic Diseases (CDIPD), Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, 92093, La Jolla, CA, USA
| | - Ido Bem-Shalom
- Center for Discovery and Innovation in Parasitic Diseases (CDIPD), Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, 92093, La Jolla, CA, USA
| | - Michael Gilson
- Center for Discovery and Innovation in Parasitic Diseases (CDIPD), Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, 92093, La Jolla, CA, USA
| | - Kurt R Brunden
- Center for Neurodegenerative Disease Research, Perelman School of Medicine, University of Pennsylvania, 3600 Spruce Street, 19104-6323, Philadelphia, PA, USA
| | - Andrea Brancale
- Cardiff School of Pharmacy and Pharmaceutical Sciences, Cardiff University, CF103NB, Cardiff, UK
- Present affiliation: Vysoká škola chemicko-technologická v Praze, Department of Organic Chemistry, Technická 5, 16628, Prague 6, Czech Republic
| | - Conor R Caffrey
- Center for Discovery and Innovation in Parasitic Diseases (CDIPD), Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, 92093, La Jolla, CA, USA
| | - Carlo Ballatore
- Center for Discovery and Innovation in Parasitic Diseases (CDIPD), Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, 92093, La Jolla, CA, USA
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Tiberti N, Longoni SS, Combes V, Piubelli C. Host-Derived Extracellular Vesicles in Blood and Tissue Human Protozoan Infections. Microorganisms 2023; 11:2318. [PMID: 37764162 PMCID: PMC10536481 DOI: 10.3390/microorganisms11092318] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 09/08/2023] [Accepted: 09/11/2023] [Indexed: 09/29/2023] Open
Abstract
Blood and tissue protozoan infections are responsible for an enormous burden in tropical and subtropical regions, even though they can also affect people living in high-income countries, mainly as a consequence of migration and travel. These pathologies are responsible for heavy socio-economic issues in endemic countries, where the lack of proper therapeutic interventions and effective vaccine strategies is still hampering their control. Moreover, the pathophysiological mechanisms associated with the establishment, progression and outcome of these infectious diseases are yet to be fully described. Among all the players, extracellular vesicles (EVs) have raised significant interest during the last decades due to their capacity to modulate inter-parasite and host-parasite interactions. In the present manuscript, we will review the state of the art of circulating host-derived EVs in clinical samples or in experimental models of human blood and tissue protozoan diseases (i.e., malaria, leishmaniasis, Chagas disease, human African trypanosomiasis and toxoplasmosis) to gain novel insights into the mechanisms of pathology underlying these conditions and to identify novel potential diagnostic markers.
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Affiliation(s)
- Natalia Tiberti
- Department of Infectious, Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, 37024 Negrar di Valpolicella, Italy; (S.S.L.); (C.P.)
| | - Silvia Stefania Longoni
- Department of Infectious, Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, 37024 Negrar di Valpolicella, Italy; (S.S.L.); (C.P.)
| | - Valéry Combes
- Microvesicles and Malaria Research Group, School of Life Sciences, Faculty of Science, University of Technology Sydney, Sydney, NSW 2007, Australia;
| | - Chiara Piubelli
- Department of Infectious, Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, 37024 Negrar di Valpolicella, Italy; (S.S.L.); (C.P.)
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Mudji J, Ackam N, Amoako YA, Madinga B, Mumbere P, Agbanyo A, Blum J, Phillips RO, Molyneux DH. Mental distress and health-related quality of life in gambiense human African trypanosomiasis: a case-control study in the Democratic Republic of Congo. Trans R Soc Trop Med Hyg 2022; 116:1022-1031. [PMID: 35474014 DOI: 10.1093/trstmh/trac035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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: 10/14/2021] [Revised: 02/17/2022] [Accepted: 04/01/2022] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND The extent to which neuropsychiatric sequelae affects the mental health status and quality of life of former gambiense human African trypanosomiasis (gHAT) patients is not known. METHODS We assessed anxiety, depression and health-related quality of life (HRQoL) in 93 patients and their age- and sex-matched controls using the Hospital Anxiety and Depression Scale, Becks Depression Inventory and the 36-item Short Form Health Survey in structured interviews in the Vanga health zone in the Democratic Republic of Congo. Data were analysed using Stata version 14.0. The degree of association between neurologic sequelae and mental distress was evaluated using the Student's t-test and χ2 or Fisher's exact tests, where appropriate, with a p-value <0.05 deemed to be statistically significant. RESULTS We found that neurological sequelae persisted in former patients at least 15 y after treatment. Depression (p<0.001) and anxiety (p=0.001) were significantly higher in former patients with neurologic sequelae. The mean quality-of-life (QoL) scores were significantly lower for patients than in controls in the physical, emotional and mental health domains. CONCLUSIONS The presence of neurological sequelae leads to mental distress and a diminished QoL in former gHAT patients. Minimising neurologic sequelae and incorporating psychosocial interventions should be essential management goals for gHAT.
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Affiliation(s)
- Junior Mudji
- Hôpital Evangélique de Vanga, Vanga Mission, B.P. 4728 Kinshasa 2, Democratic Republic of the Congo.,Department of Family Medicine and Primary Care, Protestant University of Congo, B.P. 4745, Kinshasa 2, Democratic Republic of the Congo
| | - Nancy Ackam
- Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Yaw Ampem Amoako
- Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.,School of Medicine and Dentistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.,Komfo Anokye Teaching Hospital, Kumasi, Ghana
| | - Blaise Madinga
- Hôpital Evangélique de Vanga, Vanga Mission, B.P. 4728 Kinshasa 2, Democratic Republic of the Congo.,Department of Family Medicine and Primary Care, Protestant University of Congo, B.P. 4745, Kinshasa 2, Democratic Republic of the Congo
| | - Pépé Mumbere
- Universite de Kinshasa, Centre Neuro-psycho-pathologie, Kinshasa, Democratic Republic of the Congo
| | - Abigail Agbanyo
- Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Johannes Blum
- Hôpital Evangélique de Vanga, Vanga Mission, B.P. 4728 Kinshasa 2, Democratic Republic of the Congo.,Swiss Tropical and Public Health Institute, 4002 Basel, Switzerland.,University of Basel, 4001 Basel, Switzerland
| | - Richard Odame Phillips
- Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.,School of Medicine and Dentistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.,Komfo Anokye Teaching Hospital, Kumasi, Ghana
| | - David Hurst Molyneux
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
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Bernhard S, Kaiser M, Burri C, Mäser P. Fexinidazole for Human African Trypanosomiasis, the Fruit of a Successful Public-Private Partnership. Diseases 2022; 10:90. [PMID: 36278589 PMCID: PMC9589988 DOI: 10.3390/diseases10040090] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 10/04/2022] [Accepted: 10/07/2022] [Indexed: 08/14/2023] Open
Abstract
After 100 years of chemotherapy with impractical and toxic drugs, an oral cure for human African trypanosomiasis (HAT) is available: Fexinidazole. In this case, we review the history of drug discovery for HAT with special emphasis on the discovery, pre-clinical development, and operational challenges of the clinical trials of fexinidazole. The screening of the Drugs for Neglected Diseases initiative (DNDi) HAT-library by the Swiss TPH had singled out fexinidazole, originally developed by Hoechst (now Sanofi), as the most promising of a series of over 800 nitroimidazoles and related molecules. In cell culture, fexinidazole has an IC50 of around 1 µM against Trypanosoma brucei and is more than 100-fold less toxic to mammalian cells. In the mouse model, fexinidazole cures both the first, haemolymphatic, and the second, meningoencephalitic stage of the infection, the latter at 100 mg/kg twice daily for 5 days. In patients, the clinical trials managed by DNDi and supported by Swiss TPH mainly conducted in the Democratic Republic of the Congo demonstrated that oral fexinidazole is safe and effective for use against first- and early second-stage sleeping sickness. Based on the positive opinion issued by the European Medicines Agency in 2018, the WHO has released new interim guidelines for the treatment of HAT including fexinidazole as the new therapy for first-stage and non-severe second-stage sleeping sickness caused by Trypanosoma brucei gambiense (gHAT). This greatly facilitates the diagnosis and treatment algorithm for gHAT, increasing the attainable coverage and paving the way towards the envisaged goal of zero transmission by 2030.
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Affiliation(s)
- Sonja Bernhard
- Swiss Tropical and Public Health Institute, 4123 Allschwil, Switzerland
- University of Basel, 4002 Basel, Switzerland
| | - Marcel Kaiser
- Swiss Tropical and Public Health Institute, 4123 Allschwil, Switzerland
- University of Basel, 4002 Basel, Switzerland
| | - Christian Burri
- Swiss Tropical and Public Health Institute, 4123 Allschwil, Switzerland
- University of Basel, 4002 Basel, Switzerland
| | - Pascal Mäser
- Swiss Tropical and Public Health Institute, 4123 Allschwil, Switzerland
- University of Basel, 4002 Basel, Switzerland
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Nunes JA, Ferreira da Silva-Júnior E. Hybrid-Compounds Against Trypanosomiases. Curr Drug Targets 2022; 23:1319-1329. [PMID: 35579157 DOI: 10.2174/1389450123666220509202352] [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: 12/29/2021] [Revised: 03/11/2022] [Accepted: 03/22/2022] [Indexed: 01/25/2023]
Abstract
Neglected tropical diseases (NTDs) are a global public health problem associated with approximately 20 conditions. Among these, Chagas disease (CD), caused by Trypanosoma cruzi, and human African trypanosomiasis (HAT), caused by T. brucei gambiense or T. brucei rhodesiense, affect mainly the populations of the countries from the American continent and sub- Saharan Africa. Pharmacological therapies used for such illnesses are not yet fully effective. In this context, the search for new therapeutic alternatives against these diseases becomes necessary. A drug design tool, recently recognized for its effectiveness in obtaining ligands capable of modulating multiple targets for complex diseases, concerns molecular hybridization. Therefore, this review aims to demonstrate the importance of applying molecular hybridization in facing the challenges of developing prototypes as candidates for the treatment of parasitic diseases. Therefore, studies involving different chemical classes that investigated and used hybrid compounds in recent years were compiled in this work, such as thiazolidinones, naphthoquinones, quinolines, and others. Finally, this review covers several applications of the exploration of molecular hybridization as a potent strategy in the development of molecules potentially active against trypanosomiases, in order to provide information that can help in designing new drugs with trypanocidal activity.
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Affiliation(s)
- Jessica Alves Nunes
- Institute of Chemistry and Biotechnology, Federal University of Alagoas, 57072-970, Maceió, Brazil
| | - Edeildo Ferreira da Silva-Júnior
- Institute of Chemistry and Biotechnology, Federal University of Alagoas, 57072-970, Maceió, Brazil.,Institute of Pharmaceutical Sciences, Federal University of Alagoas, 57072-970, Maceió, Brazil
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Mwiinde AM, Simuunza M, Namangala B, Chama-Chiliba CM, Machila N, Anderson NE, Atkinson PM, Welburn SC. Healthcare Management of Human African Trypanosomiasis Cases in the Eastern, Muchinga and Lusaka Provinces of Zambia. Trop Med Infect Dis 2022; 7. [PMID: 36288011 DOI: 10.3390/tropicalmed7100270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 09/16/2022] [Accepted: 09/16/2022] [Indexed: 11/26/2022] Open
Abstract
Human African trypanosomiasis (HAT) is a neglected tropical disease that has not received much attention in Zambia and most of the countries in which it occurs. In this study, we assessed the adequacy of the healthcare delivery system in diagnosis and management of rHAT cases, the environmental factors associated with transmission, the population at risk and the geographical location of rHAT cases. Structured questionnaires, focus group discussions and key informant interviews were conducted among the affected communities and health workers. The study identified 64 cases of rHAT, of which 26 were identified through active surveillance and 38 through passive surveillance. We identified a significant association between knowledge of the vector for rHAT and knowledge of rHAT transmission (p < 0.028). In all four districts, late or poor diagnosis occurred due to a lack of qualified laboratory technicians and diagnostic equipment. This study reveals that the current Zambian healthcare system is not able to adequately handle rHAT cases. Targeted policies to improve staff training in rHAT disease detection and management are needed to ensure that sustainable elimination of this public health problem is achieved in line with global targets.
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10
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Kasozi KI, MacLeod ET, Welburn SC. Systematic Review and Meta-Analysis on Human African Trypanocide Resistance. Pathogens 2022; 11:pathogens11101100. [PMID: 36297157 PMCID: PMC9612373 DOI: 10.3390/pathogens11101100] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [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: 07/24/2022] [Revised: 09/14/2022] [Accepted: 09/20/2022] [Indexed: 11/16/2022] Open
Abstract
Background Human African trypanocide resistance (HATr) is a challenge for the eradication of Human African Trypansomiaisis (HAT) following the widespread emergence of increased monotherapy drug treatment failures against Trypanosoma brucei gambiense and T. b. rhodesiense that are associated with changes in pathogen receptors. Methods: Electronic searches of 12 databases and 3 Google search websites for human African trypanocide resistance were performed using a keyword search criterion applied to both laboratory and clinical studies. Fifty-one publications were identified and included in this study using the PRISMA checklist. Data were analyzed using RevMan and random effect sizes were computed for the statistics at the 95% confidence interval. Results: Pentamidine/melarsoprol/nifurtimox cross-resistance is associated with loss of the T. brucei adenosine transporter 1/purine 2 gene (TbAT1/P2), aquaglyceroporins (TbAQP) 2 and 3, followed by the high affinity pentamidine melarsoprol transporter (HAPT) 1. In addition, the loss of the amino acid transporter (AAT) 6 is associated with eflornithine resistance. Nifurtimox/eflornithine combination therapy resistance is associated with AAT6 and nitroreductase loss, and high resistance and parasite regrowth is responsible for treatment relapse. In clinical studies, the TbAT1 proportion of total random effects was 68% (95% CI: 38.0−91.6); I2 = 96.99% (95% CI: 94.6−98.3). Treatment failure rates were highest with melarsoprol followed by eflornithine at 41.49% (95% CI: 24.94−59.09) and 6.56% (3.06−11.25) respectively. HATr-resistant phenotypes used in most laboratory experiments demonstrated significantly higher pentamidine resistance than other trypanocides. Conclusion: The emergence of drug resistance across the spectrum of trypanocidal agents that are used to treat HAT is a major threat to the global WHO target to eliminate HAT by 2030. T. brucei strains were largely resistant to diamidines and the use of high trypanocide concentrations in clinical studies have proved fatal in humans. Studies to develop novel chemotherapeutical agents and identify alternative protein targets could help to reduce the emergence and spread of HATr.
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Affiliation(s)
- Keneth Iceland Kasozi
- Infection Medicine, Deanery of Biomedical Sciences, Edinburgh Medical School, College of Medicine and Veterinary Medicine, The University of Edinburgh, Edinburgh EH8 9JZ, UK
- School of Medicine, Kabale University, Kabale P.O. Box 317, Uganda
- Correspondence: (K.I.K.); (S.C.W.)
| | - Ewan Thomas MacLeod
- Infection Medicine, Deanery of Biomedical Sciences, Edinburgh Medical School, College of Medicine and Veterinary Medicine, The University of Edinburgh, Edinburgh EH8 9JZ, UK
| | - Susan Christina Welburn
- Infection Medicine, Deanery of Biomedical Sciences, Edinburgh Medical School, College of Medicine and Veterinary Medicine, The University of Edinburgh, Edinburgh EH8 9JZ, UK
- Zhejiang University-University of Edinburgh Joint Institute, Zhejiang University, International Campus, 718 East Haizhou Road, Haining 314400, China
- Correspondence: (K.I.K.); (S.C.W.)
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11
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Bemba I, Bamou R, Lenga A, Okoko A, Awono-Ambene P, Antonio-Nkondjio C. Review of the Situation of Human African Trypanosomiasis in the Republic of Congo From the 1950s to 2020. J Med Entomol 2022; 59:421-429. [PMID: 35137146 PMCID: PMC8924973 DOI: 10.1093/jme/tjab225] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Indexed: 06/14/2023]
Abstract
Human African trypanosomiasis (HAT), despite considerable progress in the control, is still occurring in many countries in both west and central African regions. The HAT situation in the Republic of Congo has always been overshadowed by its neighbor the Democratic Republic of Congo where over 60% of all HAT cases occur. In the Republic of Congo, HAT cases have been significantly reduced to about 20 reported cases yearly and the disease is still prevalent in few foci across the country. Although continuous assessment of HAT situation in Congo is been led by the National Control Program for HAT, research on the vector, parasite, and vector control has received little attention. Because there have not been enough reviews summarizing key findings from studies conducted so far, there is still a poor understanding of the global situation of HAT in Congo. In order to achieve sustainable elimination of HAT in Congo a deep appraisal of HAT situation is required. The present study provides a review of studies conducted on HAT in the republic of Congo since the 1950s to date in order to identify gaps in knowledge and help consolidate the gains and progress towards the elimination of sleeping sickness.
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Affiliation(s)
- Irina Bemba
- Marien Ngouabi University, B.P. 69, Brazzaville, Republic of Congo
- Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), B.P. 288, Yaoundé, Cameroun
| | - Roland Bamou
- Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), B.P. 288, Yaoundé, Cameroun
- Vector Borne Diseases Laboratory of the Applied Biology and Ecology Research Unit (VBID-URBEA), Department of Animal Biology, Faculty of Science of the University of Dschang, P.O. Box 067, Cameroon
| | - Arsene Lenga
- Marien Ngouabi University, B.P. 69, Brazzaville, Republic of Congo
| | - Aline Okoko
- Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), B.P. 288, Yaoundé, Cameroun
| | - Parfait Awono-Ambene
- Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), B.P. 288, Yaoundé, Cameroun
| | - Christophe Antonio-Nkondjio
- Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), B.P. 288, Yaoundé, Cameroun
- Vector Biology Liverpool School of Tropical medicine Pembroke Place, Liverpool, UK
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12
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Dewar CE, Casas-Sanchez A, Dieme C, Crouzols A, Haines LR, Acosta-Serrano Á, Rotureau B, Schnaufer A. Oxidative Phosphorylation Is Required for Powering Motility and Development of the Sleeping Sickness Parasite Trypanosoma brucei in the Tsetse Fly Vector. mBio 2022; 13:e0235721. [PMID: 35012336 DOI: 10.1128/mbio.02357-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The single-celled parasite Trypanosoma brucei is transmitted by hematophagous tsetse flies. Life cycle progression from mammalian bloodstream form to tsetse midgut form and, subsequently, infective salivary gland form depends on complex developmental steps and migration within different fly tissues. As the parasite colonizes the glucose-poor insect midgut, ATP production is thought to depend on activation of mitochondrial amino acid catabolism via oxidative phosphorylation (OXPHOS). This process involves respiratory chain complexes and F1Fo-ATP synthase and requires protein subunits of these complexes that are encoded in the parasite's mitochondrial DNA (kDNA). Here, we show that progressive loss of kDNA-encoded functions correlates with a decreasing ability to initiate and complete development in the tsetse. First, parasites with a mutated F1Fo-ATP synthase with reduced capacity for OXPHOS can initiate differentiation from bloodstream to insect form, but they are unable to proliferate in vitro. Unexpectedly, these cells can still colonize the tsetse midgut. However, these parasites exhibit a motility defect and are severely impaired in colonizing or migrating to subsequent tsetse tissues. Second, parasites with a fully disrupted F1Fo-ATP synthase complex that is completely unable to produce ATP by OXPHOS can still differentiate to the first insect stage in vitro but die within a few days and cannot establish a midgut infection in vivo. Third, parasites lacking kDNA entirely can initiate differentiation but die soon after. Together, these scenarios suggest that efficient ATP production via OXPHOS is not essential for initial colonization of the tsetse vector but is required to power trypanosome migration within the fly. IMPORTANCE African trypanosomes cause disease in humans and their livestock and are transmitted by tsetse flies. The insect ingests these parasites with its blood meal, but to be transmitted to another mammal, the trypanosome must undergo complex development within the tsetse fly and migrate from the insect's gut to its salivary glands. Crucially, the parasite must switch from a sugar-based diet while in the mammal to a diet based primarily on amino acids when it develops in the insect. Here, we show that efficient energy production by an organelle called the mitochondrion is critical for the trypanosome's ability to swim and to migrate through the tsetse fly. Surprisingly, trypanosomes with impaired mitochondrial energy production are only mildly compromised in their ability to colonize the tsetse fly midgut. Our study adds a new perspective to the emerging view that infection of tsetse flies by trypanosomes is more complex than previously thought.
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Possart K, Herrmann FC, Jose J, Costi MP, Schmidt TJ. Sesquiterpene Lactones with Dual Inhibitory Activity against the Trypanosoma brucei Pteridine Reductase 1 and Dihydrofolate Reductase. Molecules 2021; 27:149. [PMID: 35011381 PMCID: PMC8747069 DOI: 10.3390/molecules27010149] [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] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 12/15/2021] [Accepted: 12/21/2021] [Indexed: 12/19/2022] Open
Abstract
The parasite Trypanosoma brucei (T. brucei) is responsible for human African trypanosomiasis (HAT) and the cattle disease "Nagana" which to this day cause severe medical and socio-economic issues for the affected areas in Africa. So far, most of the available treatment options are accompanied by harmful side effects and are constantly challenged by newly emerging drug resistances. Since trypanosomatids are auxotrophic for folate, their pteridine metabolism provides a promising target for an innovative chemotherapeutic treatment. They are equipped with a unique corresponding enzyme system consisting of the bifunctional dihydrofolate reductase-thymidylate synthase (TbDHFR-TS) and the pteridine reductase 1 (TbPTR1). Previously, gene knockout experiments with PTR1 null mutants have underlined the importance of these enzymes for parasite survival. In a search for new chemical entities with a dual inhibitory activity against the TbPTR1 and TbDHFR, a multi-step in silico procedure was employed to pre-select promising candidates against the targeted enzymes from a natural product database. Among others, the sesquiterpene lactones (STLs) cynaropicrin and cnicin were identified as in silico hits. Consequently, an in-house database of 118 STLs was submitted to an in silico screening yielding 29 further virtual hits. Ten STLs were subsequently tested against the target enzymes in vitro in a spectrophotometric inhibition assay. Five compounds displayed an inhibition over 50% against TbPTR1 as well as three compounds against TbDHFR. Cynaropicrin turned out to be the most interesting hit since it inhibited both TbPTR1 and TbDHFR, reaching IC50 values of 12.4 µM and 7.1 µM, respectively.
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Affiliation(s)
- Katharina Possart
- Institute of Pharmaceutical Biology and Phytochemistry (IPBP), University of Muenster, PharmaCampus, Corrensstrasse 48, D-48149 Muenster, Germany; (K.P.); (F.C.H.)
| | - Fabian C. Herrmann
- Institute of Pharmaceutical Biology and Phytochemistry (IPBP), University of Muenster, PharmaCampus, Corrensstrasse 48, D-48149 Muenster, Germany; (K.P.); (F.C.H.)
| | - Joachim Jose
- Institute of Pharmaceutical and Medicinal Chemistry, University of Muenster, PharmaCampus, Corrensstrasse 48, D-48149 Muenster, Germany;
| | - Maria P. Costi
- Department of Life Sciences, University of Modena and Reggio Emilia, Via G. Campi 103, 41125 Modena, Italy;
| | - Thomas J. Schmidt
- Institute of Pharmaceutical Biology and Phytochemistry (IPBP), University of Muenster, PharmaCampus, Corrensstrasse 48, D-48149 Muenster, Germany; (K.P.); (F.C.H.)
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14
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Previti S, Di Chio C, Ettari R, Zappalà M. Dual Inhibition of Parasitic Targets: a Valuable Strategy to Treat Malaria and Neglected Tropical Diseases. Curr Med Chem 2021; 29:2952-2978. [PMID: 34375176 DOI: 10.2174/0929867328666210810125309] [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] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 07/05/2021] [Accepted: 07/14/2021] [Indexed: 11/22/2022]
Abstract
Despite the countless efforts made in the last decades, malaria and neglected tropical diseases remain a high-impact health problem in developing countries. Malaria is one of the most severe parasitic diseases, with over 200 million cases and 400 000 deaths in 2019. Parasitic diseases caused by trypanosomatidae, namely Human African Trypanosomiasis, Chagas disease, and leishmaniasis, register the highest rates of mortality amongst all the neglected tropical diseases. In this scenario, chemotherapy remains the first strategy which aims to control and eliminate these diseases. However, the use of outdated, unsafe, and poorly effective drugs, together with the onset of resistance, prompted the researchers to the identification of new and valid targets. The innovative idea, aimed at the development of multi-target ligands addressing two different targets playing key roles in the parasite survival, could represent a valuable strategy. Thanks to this approach, the well-known limitations characterizing the antiparasitic drugs, such as toxicity, rapid resistance onset and narrow spectrum of action, could be overcome. In this review, we now describe the most recent multi-target ligands endowed with antiparasitic effect reported in the literature, focusing our attention on their binding with the targets, inhibitory activities, and potential therapeutic applications.
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Affiliation(s)
- Santo Previti
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Annunziata, 98168 Messina, Italy
| | - Carla Di Chio
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Annunziata, 98168 Messina, Italy
| | - Roberta Ettari
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Annunziata, 98168 Messina, Italy
| | - Maria Zappalà
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Annunziata, 98168 Messina, Italy
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15
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Snijders R, Fukinsia A, Claeys Y, Hasker E, Mpanya A, Miaka E, Meheus F, Boelaert M. Costs and Outcomes of Integrated Human African Trypanosomiasis Surveillance System Using Rapid Diagnostic Tests, Democratic Republic of the Congo. Emerg Infect Dis 2021; 27:2144-2153. [PMID: 34287133 PMCID: PMC8314840 DOI: 10.3201/eid2708.202399] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
We integrated sleeping sickness case detection into the primary healthcare system in 2 health districts in the Democratic Republic of the Congo. We replaced a less field-friendly serologic test with a rapid diagnostic test, which was followed up by human African trypanosomiasis microscopic testing, and used a mixed costing methodology to estimate costs from a healthcare provider perspective. We screened a total of 18,225 persons and identified 27 new cases. Average financial cost (i.e., actual expenditures) was US $6.70/person screened and $4,464/case diagnosed and treated. Average economic cost (i.e., value of resources foregone that could have been used for other purposes) was $9.40/person screened and $6,138/case diagnosed and treated. Our study shows that integrating sleeping sickness surveillance into the primary healthcare system is feasible and highlights challenges in completing the diagnostic referral process and developing a context-adapted diagnostic algorithm for the large-scale implementation of this strategy in a sustainable and low-cost manner.
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16
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Yagnik KJ, Pezo-Salazar A, Rosenbaum D, Jaso JM, Cavuoti D, Nelson B, Chancey RJ, McKenna ML, Castellino LM. A Wandering Missionary's Burden: Persistent Fever and Progressive Somnolence in a Returning Traveler. Open Forum Infect Dis 2021; 8:ofab377. [PMID: 34381849 PMCID: PMC8351803 DOI: 10.1093/ofid/ofab377] [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] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Accepted: 07/14/2021] [Indexed: 11/13/2022] Open
Abstract
Human African trypanosomiasis incidence has declined, but diagnosis remains difficult, especially in nonendemic areas. Our patient presented with fever, progressive lethargy, and weight loss for 5 months and had previously traveled to Ghana and Cameroon but had not been to areas with recently reported African trypanosomiasis. Extensive workup was negative, except for lymphocytic pleocytosis in cerebrospinal fluid; ultimately, a bone marrow aspiration revealed necrotizing granulomatous inflammation with 2 trypanosomes discovered on the aspirate smear, consistent with Trypanosoma brucei. The patient was treated with combination nifurtimox and eflornithine with full recovery.
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Affiliation(s)
- Kruti J Yagnik
- Division of Infectious Diseases and Geographic Medicine, UT Southwestern Medical Center, Dallas, Texas, USA.,Parkland Health and Hospital System, Dallas, Texas, USA
| | - Alonso Pezo-Salazar
- Division of Infectious Diseases and Geographic Medicine, UT Southwestern Medical Center, Dallas, Texas, USA.,Parkland Health and Hospital System, Dallas, Texas, USA
| | - David Rosenbaum
- Division of Pathology, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Jesse Manuel Jaso
- Division of Pathology, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Dominick Cavuoti
- Division of Pathology, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Benjamin Nelson
- Parkland Health and Hospital System, Dallas, Texas, USA.,Division of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Rebecca J Chancey
- Parasitic Diseases Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Megan L McKenna
- Division of Infectious Diseases and Geographic Medicine, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Laila M Castellino
- Division of Infectious Diseases and Geographic Medicine, UT Southwestern Medical Center, Dallas, Texas, USA
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17
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Camara M, Soumah AM, Ilboudo H, Travaillé C, Clucas C, Cooper A, Kuispond Swar NR, Camara O, Sadissou I, Calvo Alvarez E, Crouzols A, Bart JM, Jamonneau V, Camara M, MacLeod A, Bucheton B, Rotureau B. Extravascular Dermal Trypanosomes in Suspected and Confirmed Cases of gambiense Human African Trypanosomiasis. Clin Infect Dis 2021; 73:12-20. [PMID: 32638003 PMCID: PMC8246823 DOI: 10.1093/cid/ciaa897] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [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: 04/10/2020] [Accepted: 06/25/2020] [Indexed: 11/18/2022] Open
Abstract
Background The diagnosis of gambiense human African trypanosomiasis (gHAT) typically involves 2 steps: a serological screen, followed by the detection of living trypanosome parasites in the blood or lymph node aspirate. Live parasites can, however, remain undetected in some seropositive individuals, who, we hypothesize, are infected with Trypanosoma brucei gambiense parasites in their extravascular dermis. Methods To test this hypothesis, we conducted a prospective observational cohort study in the gHAT focus of Forecariah, Republic of Guinea. Of the 5417 subjects serologically screened for gHAT, 66 were enrolled into our study and underwent a dermatological examination. At enrollment, 11 seronegative, 8 unconfirmed seropositive, and 18 confirmed seropositive individuals had blood samples and skin biopsies taken and examined for trypanosomes by molecular and immunohistological methods. Results In seropositive individuals, dermatological symptoms were significantly more frequent, relative to seronegative controls. T.b. gambiense parasites were present in the blood of all confirmed cases (n = 18) but not in unconfirmed seropositive individuals (n = 8). However, T. brucei parasites were detected in the extravascular dermis of all unconfirmed seropositive individuals and all confirmed cases. Skin biopsies of all treated cases and most seropositive untreated individuals progressively became negative for trypanosomes 6 and 20 months later. Conclusions Our results highlight the skin as a potential reservoir for African trypanosomes, with implications for our understanding of this disease’s epidemiology in the context of its planned elimination and underlining the skin as a novel target for gHAT diagnostics.
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Affiliation(s)
- Mariame Camara
- Programme National de Lutte Contre la Trypanosomiase Humaine Africaine, Ministère de la Santé, Conakry, Guinea
| | - Alseny M'mah Soumah
- Programme National de Lutte Contre la Trypanosomiase Humaine Africaine, Ministère de la Santé, Conakry, Guinea.,Service de Dermatologie, Hôpital de Donka,Conakry, Guinea
| | - Hamidou Ilboudo
- Programme National de Lutte Contre la Trypanosomiase Humaine Africaine, Ministère de la Santé, Conakry, Guinea.,Institut de Recherche en Sciences de la Santé (IRSS)-Unité de Recherche Clinique de Nanoro (URCN), Nanoro, Burkina-Faso.,Institut de Recherche pour le Développement, Unité Mixte de Recherche Institut de Recherche pour le Développement (IRD)-CIRAD 177 InterTryp, Campus International de Baillarguet, Montpellier, France
| | - Christelle Travaillé
- Trypanosome Transmission Group, Trypanosome Cell Biology Unit, Institut National de la Santé et de la Recherche Médicale (INSERM) U1201 and Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France
| | - Caroline Clucas
- Wellcome Centre for Integrative Parasitology, College of Medical, Veterinary, and Life Sciences, Henry Wellcome Building for Comparative Medical Sciences, Glasgow, Scotland, United Kingdom
| | - Anneli Cooper
- Wellcome Centre for Integrative Parasitology, College of Medical, Veterinary, and Life Sciences, Henry Wellcome Building for Comparative Medical Sciences, Glasgow, Scotland, United Kingdom
| | - Nono-Raymond Kuispond Swar
- Wellcome Centre for Integrative Parasitology, College of Medical, Veterinary, and Life Sciences, Henry Wellcome Building for Comparative Medical Sciences, Glasgow, Scotland, United Kingdom.,Department of Parasitology, National Institute of Biomedical Research (INRB), Kinshasa, Democratic Republic of the Congo
| | - Oumou Camara
- Programme National de Lutte Contre la Trypanosomiase Humaine Africaine, Ministère de la Santé, Conakry, Guinea
| | - Ibrahim Sadissou
- Institut de Recherche pour le Développement, Unité Mixte de Recherche Institut de Recherche pour le Développement (IRD)-CIRAD 177 InterTryp, Campus International de Baillarguet, Montpellier, France
| | - Estefania Calvo Alvarez
- Trypanosome Transmission Group, Trypanosome Cell Biology Unit, Institut National de la Santé et de la Recherche Médicale (INSERM) U1201 and Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France
| | - Aline Crouzols
- Trypanosome Transmission Group, Trypanosome Cell Biology Unit, Institut National de la Santé et de la Recherche Médicale (INSERM) U1201 and Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France
| | - Jean-Mathieu Bart
- Institut de Recherche pour le Développement, Unité Mixte de Recherche Institut de Recherche pour le Développement (IRD)-CIRAD 177 InterTryp, Campus International de Baillarguet, Montpellier, France
| | - Vincent Jamonneau
- Institut de Recherche pour le Développement, Unité Mixte de Recherche Institut de Recherche pour le Développement (IRD)-CIRAD 177 InterTryp, Campus International de Baillarguet, Montpellier, France
| | - Mamadou Camara
- Programme National de Lutte Contre la Trypanosomiase Humaine Africaine, Ministère de la Santé, Conakry, Guinea
| | - Annette MacLeod
- Wellcome Centre for Integrative Parasitology, College of Medical, Veterinary, and Life Sciences, Henry Wellcome Building for Comparative Medical Sciences, Glasgow, Scotland, United Kingdom
| | - Bruno Bucheton
- Programme National de Lutte Contre la Trypanosomiase Humaine Africaine, Ministère de la Santé, Conakry, Guinea.,Institut de Recherche pour le Développement, Unité Mixte de Recherche Institut de Recherche pour le Développement (IRD)-CIRAD 177 InterTryp, Campus International de Baillarguet, Montpellier, France
| | - Brice Rotureau
- Trypanosome Transmission Group, Trypanosome Cell Biology Unit, Institut National de la Santé et de la Recherche Médicale (INSERM) U1201 and Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France
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18
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Kasozi KI, Zirintunda G, Ssempijja F, Buyinza B, Alzahrani KJ, Matama K, Nakimbugwe HN, Alkazmi L, Onanyang D, Bogere P, Ochieng JJ, Islam S, Matovu W, Nalumenya DP, Batiha GES, Osuwat LO, Abdelhamid M, Shen T, Omadang L, Welburn SC. Epidemiology of Trypanosomiasis in Wildlife-Implications for Humans at the Wildlife Interface in Africa. Front Vet Sci 2021; 8:621699. [PMID: 34222391 PMCID: PMC8248802 DOI: 10.3389/fvets.2021.621699] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [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: 10/26/2020] [Accepted: 05/05/2021] [Indexed: 12/18/2022] Open
Abstract
While both human and animal trypanosomiasis continue to present as major human and animal public health constraints globally, detailed analyses of trypanosome wildlife reservoir hosts remain sparse. African animal trypanosomiasis (AAT) affects both livestock and wildlife carrying a significant risk of spillover and cross-transmission of species and strains between populations. Increased human activity together with pressure on land resources is increasing wildlife–livestock–human infections. Increasing proximity between human settlements and grazing lands to wildlife reserves and game parks only serves to exacerbate zoonotic risk. Communities living and maintaining livestock on the fringes of wildlife-rich ecosystems require to have in place methods of vector control for prevention of AAT transmission and for the treatment of their livestock. Major Trypanosoma spp. include Trypanosoma brucei rhodesiense, Trypanosoma brucei gambiense, and Trypanosoma cruzi, pathogenic for humans, and Trypanosoma vivax, Trypanosoma congolense, Trypanosoma evansi, Trypanosoma brucei brucei, Trypanosoma dionisii, Trypanosoma thomasbancrofti, Trypanosma elephantis, Trypanosoma vegrandis, Trypanosoma copemani, Trypanosoma irwini, Trypanosoma copemani, Trypanosoma gilletti, Trypanosoma theileri, Trypanosoma godfreyi, Trypansoma simiae, and Trypanosoma (Megatrypanum) pestanai. Wildlife hosts for the trypansomatidae include subfamilies of Bovinae, Suidae, Pantherinae, Equidae, Alcephinae, Cercopithecinae, Crocodilinae, Pteropodidae, Peramelidae, Sigmodontidae, and Meliphagidae. Wildlife species are generally considered tolerant to trypanosome infection following centuries of coexistence of vectors and wildlife hosts. Tolerance is influenced by age, sex, species, and physiological condition and parasite challenge. Cyclic transmission through Glossina species occurs for T. congolense, T. simiae, T. vivax, T. brucei, and T. b. rhodesiense, T. b. gambiense, and within Reduviid bugs for T. cruzi. T. evansi is mechanically transmitted, and T. vixax is also commonly transmitted by biting flies including tsetse. Wildlife animal species serve as long-term reservoirs of infection, but the delicate acquired balance between trypanotolerance and trypanosome challenge can be disrupted by an increase in challenge and/or the introduction of new more virulent species into the ecosystem. There is a need to protect wildlife, animal, and human populations from the infectious consequences of encroachment to preserve and protect these populations. In this review, we explore the ecology and epidemiology of Trypanosoma spp. in wildlife.
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Affiliation(s)
- Keneth Iceland Kasozi
- Infection Medicine, Deanery of Biomedical Sciences, College of Medicine and Veterinary Medicine, The University of Edinburgh, Scotland, United Kingdom.,School of Medicine, Kabale University, Kabale, Uganda
| | - Gerald Zirintunda
- Department of Animal Production and Management, Faculty of Agriculture and Animal Sciences, Busitema University Arapai Campus, Soroti, Uganda
| | - Fred Ssempijja
- Faculty of Biomedical Sciences, Kampala International University Western Campus, Bushenyi, Uganda
| | - Bridget Buyinza
- College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Khalid J Alzahrani
- Department of Clinical Laboratories Sciences, College of Applied Medical Sciences, Taif University, Taif, Saudi Arabia
| | - Kevin Matama
- School of Pharmacy, Kampala International University Western Campus, Bushenyi, Uganda
| | - Helen N Nakimbugwe
- Department of Animal Production and Management, Faculty of Agriculture and Animal Sciences, Busitema University Arapai Campus, Soroti, Uganda.,Department of Agriculture, Faculty of Vocational Studies, Kyambogo University, Kampala, Uganda
| | - Luay Alkazmi
- Biology Department, Faculty of Applied Sciences, Umm Al-Qura University, Makkah, Saudi Arabia
| | - David Onanyang
- Department of Biology, Faculty of Science, Gulu University, Gulu, Uganda
| | - Paul Bogere
- Faculty of Agriculture and Environmental Science, Muni University, Arua, Uganda
| | - Juma John Ochieng
- Faculty of Biomedical Sciences, Kampala International University Western Campus, Bushenyi, Uganda
| | - Saher Islam
- Department of Biotechnology, Lahore College for Women University, Lahore, Pakistan
| | - Wycliff Matovu
- College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - David Paul Nalumenya
- College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Gaber El-Saber Batiha
- Department of Pharmacology and Therapeutics, Faculty of Veterinary Medicine, Damanhour University, Damanhour, Egypt
| | | | - Mahmoud Abdelhamid
- Department of Parasitology, Faculty of Veterinary Medicine, Aswan University, Aswan, Egypt
| | - Tianren Shen
- Infection Medicine, Deanery of Biomedical Sciences, College of Medicine and Veterinary Medicine, The University of Edinburgh, Scotland, United Kingdom.,Zhejiang University-University of Edinburgh Institute, Zhejiang University School of Medicine, Zhejiang University, Haining, China
| | - Leonard Omadang
- Department of Animal Production and Management, Faculty of Agriculture and Animal Sciences, Busitema University Arapai Campus, Soroti, Uganda
| | - Susan Christina Welburn
- Infection Medicine, Deanery of Biomedical Sciences, College of Medicine and Veterinary Medicine, The University of Edinburgh, Scotland, United Kingdom.,Zhejiang University-University of Edinburgh Institute, Zhejiang University School of Medicine, Zhejiang University, Haining, China
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19
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Munsimbwe L, Seetsi A, Namangala B, N’Da DD, Inoue N, Suganuma K. In Vitro and In Vivo Trypanocidal Efficacy of Synthesized Nitrofurantoin Analogs. Molecules 2021; 26:molecules26113372. [PMID: 34199682 PMCID: PMC8199755 DOI: 10.3390/molecules26113372] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 05/19/2021] [Accepted: 05/25/2021] [Indexed: 12/17/2022] Open
Abstract
African trypanosomes cause diseases in humans and livestock. Human African trypanosomiasis is caused by Trypanosoma brucei rhodesiense and T. b. gambiense. Animal trypanosomoses have major effects on livestock production and the economy in developing countries, with disease management depending mainly on chemotherapy. Moreover, only few drugs are available and these have adverse effects on patients, are costly, show poor accessibility, and parasites develop drug resistance to them. Therefore, novel trypanocidal drugs are urgently needed. Here, the effects of synthesized nitrofurantoin analogs were evaluated against six species/strains of animal and human trypanosomes, and the treatment efficacy of the selected compounds was assessed in vivo. Analogs 11 and 12, containing 11- and 12-carbon aliphatic chains, respectively, showed the highest trypanocidal activity (IC50 < 0.34 µM) and the lowest cytotoxicity (IC50 > 246.02 µM) in vitro. Structure-activity relationship analysis suggested that the trypanocidal activity and cytotoxicity were related to the number of carbons in the aliphatic chain and electronegativity. In vivo experiments, involving oral treatment with nitrofurantoin, showed partial efficacy, whereas the selected analogs showed no treatment efficacy. These results indicate that nitrofurantoin analogs with high hydrophilicity are required for in vivo assessment to determine if they are promising leads for developing trypanocidal drugs.
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Affiliation(s)
- Linous Munsimbwe
- Ministry of Fisheries and Livestock, Department of Veterinary Services, Mulungushi House, P.O. Box 50600, Ridgeway, Lusaka 15100, Zambia;
| | - Anna Seetsi
- Unit for Environmental Science and Management, Faculty of Natural and Agricultural Sciences, North-West University, Potchefstroom 2531, South Africa;
| | - Boniface Namangala
- Department of Paraclinical Studies, School of Veterinary Medicine, University of Zambia, P.O. Box 32379, Lusaka 10101, Zambia;
| | - David D. N’Da
- Centre of Excellence for Pharmaceutical Sciences (PHARMACEN), North-West University, Potchefstroom 2520, South Africa;
| | - Noboru Inoue
- OIE Reference Laboratory for Surra, National Research Centre for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan;
| | - Keisuke Suganuma
- Research Center for Global Agromedicine, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan
- Correspondence: ; Tel.: +81-155-49-5697
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Beteck RM, Jordaan A, Seldon R, Laming D, Hoppe HC, Warner DF, Khanye SD. Easy-To-Access Quinolone Derivatives Exhibiting Antibacterial and Anti-Parasitic Activities. Molecules 2021; 26:molecules26041141. [PMID: 33672753 PMCID: PMC7931078 DOI: 10.3390/molecules26041141] [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] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 02/11/2021] [Accepted: 02/13/2021] [Indexed: 11/16/2022] Open
Abstract
The cell wall of Mycobacterium tuberculosis (Mtb) has a unique structural organisation, comprising a high lipid content mixed with polysaccharides. This makes cell wall a formidable barrier impermeable to hydrophilic agents. In addition, during host infection, Mtb resides in macrophages within avascular necrotic granulomas and cavities, which shield the bacterium from the action of most antibiotics. To overcome these protective barriers, a new class of anti-TB agents exhibiting lipophilic character have been recommended by various reports in literature. Herein, a series of lipophilic heterocyclic quinolone compounds was synthesised and evaluated in vitro against pMSp12::GFP strain of Mtb, two protozoan parasites (Plasmodium falciparum and Trypanosoma brucei brucei) and against ESKAPE pathogens. The resultant compounds exhibited varied anti-Mtb activity with MIC90 values in the range of 0.24–31 µM. Cross-screening against P. falciparum and T.b. brucei, identified several compounds with antiprotozoal activities in the range of 0.4–20 µM. Compounds were generally inactive against ESKAPE pathogens, with only compounds 8c, 8g and 13 exhibiting moderate to poor activity against S. aureus and A. baumannii.
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Affiliation(s)
- Richard M. Beteck
- Centre of Excellence for Pharmaceutical Sciences, North-West University, Potchefstroom 2520, South Africa
- Correspondence: (R.M.B.); (S.D.K.); Tel.: +27-46-603-8397 (S.D.K.)
| | - Audrey Jordaan
- SAMRC/NHLS/UCT Molecular Mycobacteriology Research Unit, Department of Pathology, Faculty of Health Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town 7925, South Africa; (A.J.); (D.F.W.)
| | - Ronnett Seldon
- SAMRC Drug Discovery and Development Research Unit, University of Cape Town, Cape Town 7700, South Africa;
| | - Dustin Laming
- Centre for Chemico- and Biomedicinal Research, Rhodes University, Makhanda 6140, South Africa; (D.L.); (H.C.H.)
| | - Heinrich C. Hoppe
- Centre for Chemico- and Biomedicinal Research, Rhodes University, Makhanda 6140, South Africa; (D.L.); (H.C.H.)
- Department of Biochemistry and Microbiology, Faculty of Science, Rhodes University, Makhanda 6140, South Africa
| | - Digby F. Warner
- SAMRC/NHLS/UCT Molecular Mycobacteriology Research Unit, Department of Pathology, Faculty of Health Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town 7925, South Africa; (A.J.); (D.F.W.)
- Wellcome Centre for Infectious Diseases Research in Africa, University of Cape Town, Cape Town 7925, South Africa
| | - Setshaba D. Khanye
- Centre for Chemico- and Biomedicinal Research, Rhodes University, Makhanda 6140, South Africa; (D.L.); (H.C.H.)
- Division of Pharmaceutical Chemistry, Faculty of Pharmacy, Rhodes University, Makhanda 6140, South Africa
- Correspondence: (R.M.B.); (S.D.K.); Tel.: +27-46-603-8397 (S.D.K.)
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Muraca G, Berti IR, Sbaraglini ML, Fávaro WJ, Durán N, Castro GR, Talevi A. Trypanosomatid-Caused Conditions: State of the Art of Therapeutics and Potential Applications of Lipid-Based Nanocarriers. Front Chem 2020; 8:601151. [PMID: 33324615 PMCID: PMC7726426 DOI: 10.3389/fchem.2020.601151] [Citation(s) in RCA: 6] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 10/19/2020] [Indexed: 11/13/2022] Open
Abstract
Trypanosomatid-caused conditions (African trypanosomiasis, Chagas disease, and leishmaniasis) are neglected tropical infectious diseases that mainly affect socioeconomically vulnerable populations. The available therapeutics display substantial limitations, among them limited efficacy, safety issues, drug resistance, and, in some cases, inconvenient routes of administration, which made the scenarios with insufficient health infrastructure settings inconvenient. Pharmaceutical nanocarriers may provide solutions to some of these obstacles, improving the efficacy-safety balance and tolerability to therapeutic interventions. Here, we overview the state of the art of therapeutics for trypanosomatid-caused diseases (including approved drugs and drugs undergoing clinical trials) and the literature on nanolipid pharmaceutical carriers encapsulating approved and non-approved drugs for these diseases. Numerous studies have focused on the obtention and preclinical assessment of lipid nanocarriers, particularly those addressing the two currently most challenging trypanosomatid-caused diseases, Chagas disease, and leishmaniasis. In general, in vitro and in vivo studies suggest that delivering the drugs using such type of nanocarriers could improve the efficacy-safety balance, diminishing cytotoxicity and organ toxicity, especially in leishmaniasis. This constitutes a very relevant outcome, as it opens the possibility to extended treatment regimens and improved compliance. Despite these advances, last-generation nanosystems, such as targeted nanocarriers and hybrid systems, have still not been extensively explored in the field of trypanosomatid-caused conditions and represent promising opportunities for future developments. The potential use of nanotechnology in extended, well-tolerated drug regimens is particularly interesting in the light of recent descriptions of quiescent/dormant stages of Leishmania and Trypanosoma cruzi, which have been linked to therapeutic failure.
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Affiliation(s)
- Giuliana Muraca
- Laboratory of Bioactive Research and Development (LIDeB), Department of Biological Sciences, Faculty of Exact Sciences, University of La Plata (UNLP), La Plata, Argentina
- Administración Nacional de Medicamentos, Alimentos y Tecnología Médica (ANMAT), Buenos Aires, Argentina
| | - Ignacio Rivero Berti
- Laboratorio de Nanobiomateriales, Centro de Investigación y Desarrollo en Fermentaciones Industriales (CINDEFI), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata (UNLP) -CONICET (CCT La Plata), La Plata, Argentina
| | - María L. Sbaraglini
- Laboratory of Bioactive Research and Development (LIDeB), Department of Biological Sciences, Faculty of Exact Sciences, University of La Plata (UNLP), La Plata, Argentina
| | - Wagner J. Fávaro
- Laboratory of Urogenital Carcinogenesis and Immunotherapy, Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil
| | - Nelson Durán
- Laboratory of Urogenital Carcinogenesis and Immunotherapy, Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil
- Nanomedicine Research Unit (Nanomed), Federal University of ABC (UFABC), Santo André, Brazil
| | - Guillermo R. Castro
- Laboratorio de Nanobiomateriales, Centro de Investigación y Desarrollo en Fermentaciones Industriales (CINDEFI), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata (UNLP) -CONICET (CCT La Plata), La Plata, Argentina
| | - Alan Talevi
- Laboratory of Bioactive Research and Development (LIDeB), Department of Biological Sciences, Faculty of Exact Sciences, University of La Plata (UNLP), La Plata, Argentina
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Benelli G, Petrelli R, Canale A. Arthropod-Borne Disease Control at a Glance: What's New on Drug Development? Molecules 2020; 25:E5175. [PMID: 33172077 DOI: 10.3390/molecules25215175] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 11/04/2020] [Indexed: 12/17/2022] Open
Abstract
Discovering and validating effective drugs to manage arthropod-borne diseases (ABD) is a timely and important research challenge with major impacts on real-world control programs at the time of quick resistance development in the targeted pathogens. This editorial highlights major research advances in the development of drugs for the control of vector-borne diseases, with a significant focus on malaria, Chagas disease, dengue, human African trypanosomiasis, leishmaniasis, and Zika. Broad reviews providing new insights on ABD recently published in Molecules have also been covered in “The Editors’ pick” section.
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Lemerani M, Jumah F, Bessell P, Biéler S, Ndung'u JM. Improved Access to Diagnostics for Rhodesian Sleeping Sickness around a Conservation Area in Malawi Results in Earlier Detection of Cases and Reduced Mortality. J Epidemiol Glob Health 2020; 10:280-287. [PMID: 32959623 PMCID: PMC7758844 DOI: 10.2991/jegh.k.200321.001] [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: 10/28/2019] [Accepted: 01/25/2020] [Indexed: 11/01/2022] Open
Abstract
Trypanosoma brucei rhodesiense Human African Trypanosomiasis (rHAT) is a zoonotic disease transmitted by tsetse flies from wild and domestic animals. It presents as an acute disease and advances rapidly into a neurological form that can only be treated with melarsoprol, which is associated with a high fatality rate. Bringing diagnostic services for rHAT closer to at-risk populations would increase chances of detecting cases in early stages of disease when treatment is safer and more effective. In Malawi, most of the rHAT cases occur around Vwaza Marsh Wildlife Reserve. Until 2013, diagnosis of rHAT in the region was only available at the Rumphi District Hospital that is more than 60 km away from the reserve. In 2013, Malawi's Ministry of Health initiated a project to enhance the detection of rHAT in five health facilities around Vwaza Marsh by upgrading laboratories and training technicians. We report here a retrospective study that was carried out to evaluate the impact of improving access to diagnostic services on the disease stage at diagnosis and on mortality. Between August 2014 and July 2017, 2014 patients suspected of having the disease were tested by microscopy, including 1267 who were tested in the new facilities. This resulted in the identification of 78 new rHAT cases, of which six died. Compared with previous years, data obtained during this period indicate that access to diagnostic services closer to where people at the greatest risk of infection live promotes identification of cases in earlier stages of infection, and improves treatment outcomes.
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Affiliation(s)
| | | | | | - Sylvain Biéler
- Foundation for Innovative New Diagnostics (FIND), Geneva, Switzerland
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Pilotte N, Cook DA, Pryce J, Zulch MF, Minetti C, Reimer LJ, Williams SA. Laboratory evaluation of molecular xenomonitoring using mosquito and tsetse fly excreta/feces to amplify Plasmodium, Brugia, and Trypanosoma DNA. Gates Open Res 2020; 3:1734. [PMID: 32596646 PMCID: PMC7308644 DOI: 10.12688/gatesopenres.13093.2] [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] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/20/2020] [Indexed: 11/20/2022] Open
Abstract
Background: Results from an increasing number of studies suggest that mosquito excreta/feces (E/F) testing has considerable potential to serve as a supplement for traditional molecular xenomonitoring techniques. However, as the catalogue of possible use-cases for this methodology expands, and the list of amenable pathogens grows, a number of fundamental methods-based questions remain. Answering these questions is critical to maximizing the utility of this approach and to facilitating its successful implementation as an effective tool for molecular xenomonitoring. Methods: Utilizing E/F produced by mosquitoes or tsetse flies experimentally exposed to Brugia malayi, Plasmodium falciparum, or Trypanosoma brucei brucei, factors such as limits of detection, throughput of testing, adaptability to use with competent and incompetent vector species, and effects of additional blood feedings post parasite-exposure were evaluated. Two platforms for the detection of pathogen signal (quantitative real-time PCR and digital PCR (dPCR)) were also compared, with strengths and weaknesses examined for each. Results: Experimental results indicated that high throughput testing is possible when evaluating mosquito E/F for the presence of either B. malayi or P. falciparum from both competent and incompetent vector mosquito species. Furthermore, following exposure to pathogen, providing mosquitoes with a second, uninfected bloodmeal did not expand the temporal window for E/F collection during which pathogen detection was possible. However, this collection window did appear longer in E/F collected from tsetse flies following exposure to T. b. brucei. Testing also suggested that dPCR may facilitate detection through its increased sensitivity. Unfortunately, logistical obstacles will likely make the large-scale use of dPCR impractical for this purpose. Conclusions: By examining many E/F testing variables, expansion of this technology to a field-ready platform has become increasingly feasible. However, translation of this methodology from the lab to the field will first require field-based pilot studies aimed at assessing the efficacy of E/F screening.
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Affiliation(s)
- Nils Pilotte
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, 01063, USA
- Molecular and Cellular Biology Program, University of Massachusetts, Amherst, Massachusetts, 01003, USA
| | - Darren A.N. Cook
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Joseph Pryce
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Michael F. Zulch
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, 01063, USA
| | - Corrado Minetti
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Lisa J. Reimer
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Steven A. Williams
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, 01063, USA
- Molecular and Cellular Biology Program, University of Massachusetts, Amherst, Massachusetts, 01003, USA
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Landi G, Linciano P, Tassone G, Costi MP, Mangani S, Pozzi C. High-resolution crystal structure of Trypanosoma brucei pteridine reductase 1 in complex with an innovative tricyclic-based inhibitor. Acta Crystallogr D Struct Biol 2020; 76:558-564. [PMID: 32496217 DOI: 10.1107/s2059798320004891] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [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: 11/05/2019] [Accepted: 04/06/2020] [Indexed: 11/10/2022] Open
Abstract
The protozoan parasite Trypanosoma brucei is the etiological agent of human African trypanosomiasis (HAT). HAT, together with other neglected tropical diseases, causes serious health and economic issues, especially in tropical and subtropical areas. The classical antifolates targeting dihydrofolate reductase (DHFR) are ineffective towards trypanosomatid parasites owing to a metabolic bypass by the expression of pteridine reductase 1 (PTR1). The combined inhibition of PTR1 and DHFR activities in Trypanosoma parasites represents a promising strategy for the development of new effective treatments for HAT. To date, only monocyclic and bicyclic aromatic systems have been proposed as inhibitors of T. brucei PTR1 (TbPTR1); nevertheless, the size of the catalytic cavity allows the accommodation of expanded molecular cores. Here, an innovative tricyclic-based compound has been explored as a TbPTR1-targeting molecule and its potential application for the development of a new class of PTR1 inhibitors has been evaluated. 2,4-Diaminopyrimido[4,5-b]indol-6-ol (1) was designed and synthesized, and was found to be effective in blocking TbPTR1 activity, with a Ki in the low-micromolar range. The binding mode of 1 was clarified through the structural characterization of its ternary complex with TbPTR1 and the cofactor NADP(H), which was determined to 1.30 Å resolution. The compound adopts a substrate-like orientation inside the cavity that maximizes the binding contributions of hydrophobic and hydrogen-bond interactions. The binding mode of 1 was compared with those of previously reported bicyclic inhibitors, providing new insights for the design of innovative tricyclic-based molecules targeting TbPTR1.
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Affiliation(s)
- Giacomo Landi
- Department of Biotechnology, Chemistry and Pharmacy - Department of Excellence 2018-2022, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
| | - Pasquale Linciano
- Department of Life Science, University of Modena and Reggio Emilia, Via Campi 103, 41125 Modena, Italy
| | - Giusy Tassone
- Department of Biotechnology, Chemistry and Pharmacy - Department of Excellence 2018-2022, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
| | - Maria Paola Costi
- Department of Life Science, University of Modena and Reggio Emilia, Via Campi 103, 41125 Modena, Italy
| | - Stefano Mangani
- Department of Biotechnology, Chemistry and Pharmacy - Department of Excellence 2018-2022, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
| | - Cecilia Pozzi
- Department of Biotechnology, Chemistry and Pharmacy - Department of Excellence 2018-2022, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
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Nkieri M, Mbo F, Kavunga P, Nganzobo P, Mafolo T, Selego C, Mwamba Miaka E. An Active Follow-up Strategy for Serological Suspects of Human African Trypanosomiasis with Negative Parasitology Set up by a Health Zone Team in the Democratic Republic of Congo. Trop Med Infect Dis 2020; 5:tropicalmed5020053. [PMID: 32260405 PMCID: PMC7345707 DOI: 10.3390/tropicalmed5020053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [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: 01/06/2020] [Revised: 04/01/2020] [Accepted: 04/02/2020] [Indexed: 11/16/2022] Open
Abstract
Background: The World Health Organization aims for the elimination of Human African Trypanosomiasis (HAT) as a public health problem by 2020 and for full elimination (absence of new cases) by 2030. One of strategies to achieve this is the active follow-up of all HAT serological suspects found during passive screening who have never been re-tested for parasitology. This is important because these cases can maintain HAT transmission and may be responsible for reemergence of the disease. Methods: In order to improve case finding at low cost in the targeted population, a general recall was transmitted to aparasitemic serological suspects about the availability of confirmation services at the general referral hospital. Transport was facilitated for re-testing. The initial examinations were carried out in Health Centers from Bagata Health Zone (HZ) in the Democratic Republic of the Congo between January 2017 and April 2019. This strategy of using a HZ team has not been previously documented. Results: From a total sample of 74 serological suspects listed by the health centers, 36 cases were re-examined at the general reference hospital; 19% (7/36) self-presented and 81% (29/36) were actively followed up by HZ personnel. Of those re-examined at the general reference hospital, 39% (14/36) resulted in a parasitologically confirmed case. Of the 14 people diagnosed with HAT, 14% (2/14) self-presented and the remaining 86% (12/14) were diagnosed in suspects who were actively followed up. This new strategy of facilitating transport from the villages added value by contributing to the detection of 12 HAT cases, compared to the passive approach, waiting for self-reference, which resulted in the detection of 2 new HAT cases. The cost per detected patient was 70 USD from the group of 7 suspects who self-presented for testing at the hospital and 346 USD per detected case for the group of 29 patients who were actively followed up by health zone staff. Conclusion: Targeted active follow-up of aparasitemic serological suspects by HZ teams is a cost-effective and promising approach to identifying additional cases of HAT in areas of very low prevalence, which would contribute to the HAT elimination goal set by the World Health Organization.
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Affiliation(s)
- Matthieu Nkieri
- Bagata Health Zone, Avenue Kalanganda N 10, Mwendo Bagata,32 Kwilu Province, Democratic Republic of the Congo; (M.N.); (P.K.)
| | - Florent Mbo
- National Sleeping Sickness Control Program (PNLTHA) (PNMLS building), Boulevard Triomphale Crossing Av. 24 November, 10 Kinshasa, Democratic Republic of the Congo; (P.N.); (E.M.M.)
- HAT Platform, Avenue Milambo N 4 Quartier Socimat, Gombe, 10 Kinshasa, Democratic Republic of the Congo
- Correspondence: or ; Tel.: +243-814313838
| | - Papy Kavunga
- Bagata Health Zone, Avenue Kalanganda N 10, Mwendo Bagata,32 Kwilu Province, Democratic Republic of the Congo; (M.N.); (P.K.)
| | - Pathou Nganzobo
- National Sleeping Sickness Control Program (PNLTHA) (PNMLS building), Boulevard Triomphale Crossing Av. 24 November, 10 Kinshasa, Democratic Republic of the Congo; (P.N.); (E.M.M.)
| | - Titus Mafolo
- Provincial Health Ministry of Kwilu, Aviation/Ifuri/Bandundu town, Bandundu, Democratic Republic of the Congo; (T.M.); (C.S.)
| | - Chalet Selego
- Provincial Health Ministry of Kwilu, Aviation/Ifuri/Bandundu town, Bandundu, Democratic Republic of the Congo; (T.M.); (C.S.)
| | - Eric Mwamba Miaka
- National Sleeping Sickness Control Program (PNLTHA) (PNMLS building), Boulevard Triomphale Crossing Av. 24 November, 10 Kinshasa, Democratic Republic of the Congo; (P.N.); (E.M.M.)
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Palmer JJ, Jones C, Surur EI, Kelly AH. Understanding the Role of the Diagnostic 'Reflex' in the Elimination of Human African Trypanosomiasis. Trop Med Infect Dis 2020; 5:tropicalmed5020052. [PMID: 32244778 PMCID: PMC7345297 DOI: 10.3390/tropicalmed5020052] [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] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Revised: 03/20/2020] [Accepted: 03/26/2020] [Indexed: 11/16/2022] Open
Abstract
To successfully eliminate human African trypanosomiasis (HAT), healthcare workers (HCWs) must maintain their diagnostic acuity to identify cases as the disease becomes rarer. HAT experts refer to this concept as a ‘reflex’ which incorporates the idea that diagnostic expertise, particularly skills involved in recognising which patients should be tested, comes from embodied knowledge, accrued through practice. We investigated diagnostic pathways in the detection of 32 symptomatic HAT patients in South Sudan and found that this ‘reflex’ was not confined to HCWs. Indeed, lay people suggested patients test for HAT in more than half of cases using similar practices to HCWs, highlighting the importance of the expertise present in disease-affected communities. Three typologies of diagnostic practice characterised patients’ detection: ‘syndromic suspicion’, which closely resembled the idea of an expert diagnostic reflex, as well as ‘pragmatic testing’ and ‘serendipitous detection’, which depended on diagnostic expertise embedded in hospital and lay social structures when HAT-specific suspicion was ambivalent or even absent. As we approach elimination, health systems should embrace both expert and non-expert forms of diagnostic practice that can lead to detection. Supporting multidimensional access to HAT tests will be vital for HCWs and lay people to practice diagnosis and develop their expertise.
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Affiliation(s)
- Jennifer J. Palmer
- Department of Global Health & Development, London School of Hygiene & Tropical Medicine, 15–17 Tavistock Place, London WC1H 9SH, UK
- Centre of African Studies, University of Edinburgh, 15a George Square, Edinburgh EH8 9LD, UK
- Correspondence:
| | - Caroline Jones
- Kemri-Wellcome Trust Research Programme, P.O. Box 230, Kilifi 80108, Kenya;
| | | | - Ann H. Kelly
- Department of Global Health & Social Medicine, King’s College London, 30 Aldwych, London WC2B 4BG, UK;
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Mbo F, Mutombo W, Ngolo D, Kabangu P, Valverde Mordt O, Wourgaft NS, Mwamba E. How Clinical Research Can Contribute to Strengthening Health Systems in Low Resource Countries. Trop Med Infect Dis 2020; 5:tropicalmed5020048. [PMID: 32235362 PMCID: PMC7345178 DOI: 10.3390/tropicalmed5020048] [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] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 03/19/2020] [Accepted: 03/20/2020] [Indexed: 12/04/2022] Open
Abstract
Clinical research on neglected tropical diseases is a challenge in low-resource countries, and the contribution of clinical and operational research to health system strengthening is poorly documented. Developing new, simple, safe, and effective treatments may improve the effectiveness of health systems, and conducting research directly in health structures may have an additional impact. This study describes the process of conducting clinical trials in the Democratic Republic of Congo (DRC) in compliance with international standards, and the role of the trials in strengthening health system functions, including governance, human resources, health information, provision of care, and the equipping of health services with the necessary supplies and infrastructure. We conclude that conducting clinical trials in endemic areas has not only reinforced and supported the aim of conducting high-level clinical research in endemic countries, but has also brought lasting benefits to researchers, staff, and hospitals, as well as to broader health systems, which have positive knock-on effect on patients outside of the clinical trials and their communities. Sustainability, however, remains a challenge in an underfunded health system, especially with respect to specialized equipment. Clinical research in most of sub-Saharan Africa is highly dependent on international input and external technical support; there are areas of weaknesses in trial design and documentation, as well as in data management and analysis. Financing remains a critical issue, as African investigators have difficulties in directly accessing sources of international research funding.
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Affiliation(s)
- Florent Mbo
- HAT Platform, Drugs for Neglected Diseases initiative, Avenue Milambo, N 4, Quartier Socimat, Gombe, Kinshasa 7948, Democratic Republic of Congo
- Le Programme Nationale de Lutte contre la Trypanosomiase Humaine Africaine (PNLTHA), croisement du Boulevard Triomphal avec l’avenue de la Libération, Commune de Kasa-Vubu, Kinshasa 7948, Democratic Republic of Congo; (D.N.); (P.K.); (E.M.)
- Correspondence: ; Tel.: +243814313838
| | - Wilfried Mutombo
- Drugs for Neglected Diseases initiative (DNDi), Avenue Milambo, N 4, Quartier Socimat, Gombe, Kinshasa 7948, Democratic Republic of Congo;
| | - Digas Ngolo
- Le Programme Nationale de Lutte contre la Trypanosomiase Humaine Africaine (PNLTHA), croisement du Boulevard Triomphal avec l’avenue de la Libération, Commune de Kasa-Vubu, Kinshasa 7948, Democratic Republic of Congo; (D.N.); (P.K.); (E.M.)
| | - Patrice Kabangu
- Le Programme Nationale de Lutte contre la Trypanosomiase Humaine Africaine (PNLTHA), croisement du Boulevard Triomphal avec l’avenue de la Libération, Commune de Kasa-Vubu, Kinshasa 7948, Democratic Republic of Congo; (D.N.); (P.K.); (E.M.)
| | - Olaf Valverde Mordt
- Drugs for Neglected Diseases initiative, 15 Chemin Louis-Dunant, 1202 Geneva, Switzerland; (O.V.M.); (N.S.W.)
| | - Nathalie Strub Wourgaft
- Drugs for Neglected Diseases initiative, 15 Chemin Louis-Dunant, 1202 Geneva, Switzerland; (O.V.M.); (N.S.W.)
| | - Erick Mwamba
- Le Programme Nationale de Lutte contre la Trypanosomiase Humaine Africaine (PNLTHA), croisement du Boulevard Triomphal avec l’avenue de la Libération, Commune de Kasa-Vubu, Kinshasa 7948, Democratic Republic of Congo; (D.N.); (P.K.); (E.M.)
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Sereno D, Akhoundi M, Sayehmri K, Mirzaei A, Holzmuller P, Lejon V, Waleckx E. Noninvasive Biological Samples to Detect and Diagnose Infections due to Trypanosomatidae Parasites: A Systematic Review and Meta-Analysis. Int J Mol Sci 2020; 21:E1684. [PMID: 32121441 PMCID: PMC7084391 DOI: 10.3390/ijms21051684] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [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: 01/27/2020] [Revised: 02/24/2020] [Accepted: 02/25/2020] [Indexed: 12/24/2022] Open
Abstract
Unicellular eukaryotes of the Trypanosomatidae family include human and animal pathogens that belong to the Trypanosoma and Leishmania genera. Diagnosis of the diseases they cause requires the sampling of body fluids (e.g., blood, lymph, peritoneal fluid, cerebrospinal fluid) or organ biopsies (e.g., bone marrow, spleen), which are mostly obtained through invasive methods. Body fluids or appendages can be alternatives to these invasive biopsies but appropriateness remains poorly studied. To further address this question, we perform a systematic review on clues evidencing the presence of parasites, genetic material, antibodies, and antigens in body secretions, appendages, or the organs or proximal tissues that produce these materials. Paper selection was based on searches in PubMed, Web of Science, WorldWideScience, SciELO, Embase, and Google. The information of each selected article (n = 333) was classified into different sections and data were extracted from 77 papers. The presence of Trypanosomatidae parasites has been tracked in most of organs or proximal tissues that produce body secretions or appendages, in naturally or experimentally infected hosts. The meta-analysis highlights the paucity of studies on human African trypanosomiasis and an absence on animal trypanosomiasis. Among the collected data high heterogeneity in terms of the I2 statistic (100%) is recorded. A high positivity is recorded for antibody and genetic material detection in urine of patients and dogs suffering leishmaniasis, and of antigens for leishmaniasis and Chagas disease. Data on conjunctival swabs can be analyzed with molecular methods solely for dogs suffering canine visceral leishmaniasis. Saliva and hair/bristles showed a pretty good positivity that support their potential to be used for leishmaniasis diagnosis. In conclusion, our study pinpoints significant gaps that need to be filled in order to properly address the interest of body secretion and hair or bristles for the diagnosis of infections caused by Leishmania and by other Trypanosomatidae parasites.
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Affiliation(s)
- Denis Sereno
- Institut de Recherche pour le Dévelopement, Université de Montpellier, UMR INTERTRYP IRD, CIRAD, 34032 Montpellier, France; (V.L.); (E.W.)
- Institut de Recherche pour le Dévelopement, Université de Montpellier, UMR MIVEGEC IRD, CNRS, 34032 Montpellier, France
| | - Mohammad Akhoundi
- Parasitology-Mycology Department, Avicenne Hospital, AP-HP, 93000 Bobigny, France;
| | - Kourosh Sayehmri
- Psychosocial Injuries Research Center, Department of Biostatistics, Ilam University of Medical Sciences, Ilam 6931851147, Iran;
| | - Asad Mirzaei
- Parasitology Department, Paramedical School, Ilam University of Medical Sciences, Ilam 6931851147, Iran;
- Zoonotic Diseases Research Center, Ilam University of Medical Sciences, Ilam 6931851147, Iran
| | - Philippe Holzmuller
- CIRAD, UMR ASTRE “Animal, Santé, Territoires, Risques et Ecosystèmes”, F-34398 Montpellier, France;
- ASTRE, CIRAD, INRAE, Université de Montpellier (I-MUSE), 34000 Montpellier, France
| | - Veerle Lejon
- Institut de Recherche pour le Dévelopement, Université de Montpellier, UMR INTERTRYP IRD, CIRAD, 34032 Montpellier, France; (V.L.); (E.W.)
| | - Etienne Waleckx
- Institut de Recherche pour le Dévelopement, Université de Montpellier, UMR INTERTRYP IRD, CIRAD, 34032 Montpellier, France; (V.L.); (E.W.)
- Centro de Investigaciones Regionales «Dr Hideyo Noguchi», Universidad autònoma de yucatán, Merida, Yucatán 97000, Mexico
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Abstract
Suramin is 100 years old and is still being used to treat the first stage of acute human sleeping sickness, caused by Trypanosoma brucei rhodesiense Suramin is a multifunctional molecule with a wide array of potential applications, from parasitic and viral diseases to cancer, snakebite, and autism. Suramin is also an enigmatic molecule: What are its targets? How does it get into cells in the first place? Here, we provide an overview of the many different candidate targets of suramin and discuss its modes of action and routes of cellular uptake. We reason that, once the polypharmacology of suramin is understood at the molecular level, new, more specific, and less toxic molecules can be identified for the numerous potential applications of suramin.
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Dickie EA, Giordani F, Gould MK, Mäser P, Burri C, Mottram JC, Rao SPS, Barrett MP. New Drugs for Human African Trypanosomiasis: A Twenty First Century Success Story. Trop Med Infect Dis 2020; 5:tropicalmed5010029. [PMID: 32092897 PMCID: PMC7157223 DOI: 10.3390/tropicalmed5010029] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [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: 01/16/2020] [Revised: 02/12/2020] [Accepted: 02/14/2020] [Indexed: 12/23/2022] Open
Abstract
The twentieth century ended with human African trypanosomiasis (HAT) epidemics raging across many parts of Africa. Resistance to existing drugs was emerging, and many programs aiming to contain the disease had ground to a halt, given previous success against HAT and the competing priorities associated with other medical crises ravaging the continent. A series of dedicated interventions and the introduction of innovative routes to develop drugs, involving Product Development Partnerships, has led to a dramatic turnaround in the fight against HAT caused by Trypanosoma brucei gambiense. The World Health Organization have been able to optimize the use of existing tools to monitor and intervene in the disease. A promising new oral medication for stage 1 HAT, pafuramidine maleate, ultimately failed due to unforeseen toxicity issues. However, the clinical trials for this compound demonstrated the possibility of conducting such trials in the resource-poor settings of rural Africa. The Drugs for Neglected Disease initiative (DNDi), founded in 2003, has developed the first all oral therapy for both stage 1 and stage 2 HAT in fexinidazole. DNDi has also brought forward another oral therapy, acoziborole, potentially capable of curing both stage 1 and stage 2 disease in a single dosing. In this review article, we describe the remarkable successes in combating HAT through the twenty first century, bringing the prospect of the elimination of this disease into sight.
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Affiliation(s)
- Emily A. Dickie
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow G12 8TA, UK; (E.A.D.); (F.G.); (M.K.G.)
| | - Federica Giordani
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow G12 8TA, UK; (E.A.D.); (F.G.); (M.K.G.)
| | - Matthew K. Gould
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow G12 8TA, UK; (E.A.D.); (F.G.); (M.K.G.)
| | - Pascal Mäser
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002 Basel, Switzerland; (P.M.); (C.B.)
| | - Christian Burri
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002 Basel, Switzerland; (P.M.); (C.B.)
- University of Basel, Petersplatz 1, 4000 Basel, Switzerland
| | - Jeremy C. Mottram
- York Biomedical Research Institute, Department of Biology, University of York, Wentworth Way, Heslington, York YO10 5DD, UK;
| | - Srinivasa P. S. Rao
- Novartis Institute for Tropical Diseases, 5300 Chiron Way, Emeryville, CA 94608, USA;
| | - Michael P. Barrett
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow G12 8TA, UK; (E.A.D.); (F.G.); (M.K.G.)
- Correspondence:
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Matovu E, Mugasa CM, Waiswa P, Kitibwa A, Boobo A, Ndung’u JM. Haemoparasitic Infections in Cattle from a Trypanosoma brucei Rhodesiense Sleeping Sickness Endemic District of Eastern Uganda. Trop Med Infect Dis 2020; 5:tropicalmed5010024. [PMID: 32046044 PMCID: PMC7157584 DOI: 10.3390/tropicalmed5010024] [Citation(s) in RCA: 6] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 01/27/2020] [Accepted: 02/03/2020] [Indexed: 11/16/2022] Open
Abstract
We carried out a baseline survey of cattle in Kaberamaido district, in the context of controlling the domestic animal reservoir of Trypanosoma brucei rhodesiense human African trypanosomiasis (rHAT) towards elimination. Cattle blood was subjected to capillary tube centrifugation followed by measurement of the packed cell volume (PCV) and examination of the buffy coat area for motile trypanosomes. Trypanosomes were detected in 561 (21.4%) out of 2621 cattle screened by microscopy. These 561 in addition to 724 apparently trypanosome negative samples with low PCVs (≤25%) were transported to the laboratory and tested by PCR targeting the trypanosomal Internal Transcribed Spacer (ITS-1) as well as suspect Tick-Borne Diseases (TBDs) including Anaplasmamosis, Babesiosis, and Theileriosis. PCR for Anaplasma sp yielded the highest number of positive animals (45.2%), followed by Trypanosoma sp (44%), Theileria sp (42.4%) and Babesia (26.3%); multiple infections were a common occurrence. Interestingly, 373 (29%) of these cattle with low PCVs were negative by PCR, pointing to other possible causes of aneamia, such as helminthiasis. Among the trypanosome infections classified as T. brucei by ITS-PCR, 5.5% were positive by SRA PCR, and were, therefore, confirmed as T. b. rhodesiense. Efforts against HAT should therefore consider packages that address a range of conditions. This may enhance acceptability and participation of livestock keepers in programs to eliminate this important but neglected tropical disease. In addition, we demonstrated that cattle remain an eminent reservoir for T. b. rhodesiense in eastern Uganda, which must be addressed to sustain HAT elimination.
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Affiliation(s)
- Enock Matovu
- College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University Kampala, P.O. Box 7062 Kampala, Uganda; (E.M.); (P.W.); (A.K.); (A.B.)
| | - Claire Mack Mugasa
- College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University Kampala, P.O. Box 7062 Kampala, Uganda; (E.M.); (P.W.); (A.K.); (A.B.)
- Correspondence:
| | - Peter Waiswa
- College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University Kampala, P.O. Box 7062 Kampala, Uganda; (E.M.); (P.W.); (A.K.); (A.B.)
| | - Annah Kitibwa
- College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University Kampala, P.O. Box 7062 Kampala, Uganda; (E.M.); (P.W.); (A.K.); (A.B.)
| | - Alex Boobo
- College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University Kampala, P.O. Box 7062 Kampala, Uganda; (E.M.); (P.W.); (A.K.); (A.B.)
| | - Joseph Mathu Ndung’u
- Foundation for Innovative New Diagnostics, Campus Biotech, Chemin des Mines 9, CH 1202 Geneva, Switzerland;
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Buckner FS, Buchynskyy A, Nagendar P, Patrick DA, Gillespie JR, Herbst Z, Tidwell RR, Gelb MH. Phenotypic Drug Discovery for Human African Trypanosomiasis: A Powerful Approach. Trop Med Infect Dis 2020; 5:E23. [PMID: 32033395 DOI: 10.3390/tropicalmed5010023] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 01/31/2020] [Accepted: 02/02/2020] [Indexed: 11/24/2022] Open
Abstract
The work began with the screening of a library of 700,000 small molecules for inhibitors of Trypanosoma brucei growth (a phenotypic screen). The resulting set of 1035 hit compounds was reviewed by a team of medicinal chemists, leading to the nomination of 17 chemically distinct scaffolds for further investigation. The first triage step was the assessment for brain permeability (looking for brain levels at least 20% of plasma levels) in order to optimize the chances of developing candidates for treating late-stage human African trypanosomiasis. Eleven scaffolds subsequently underwent hit-to-lead optimization using standard medicinal chemistry approaches. Over a period of six years in an academic setting, 1539 analogs to the 11 scaffolds were synthesized. Eight scaffolds were discontinued either due to insufficient improvement in antiparasitic activity (5), poor pharmacokinetic properties (2), or a slow (static) antiparasitic activity (1). Three scaffolds were optimized to the point of curing the acute and/or chronic T. brucei infection model in mice. The progress was accomplished without knowledge of the mechanism of action (MOA) for the compounds, although the MOA has been discovered in the interim for one compound series. Studies on the safety and toxicity of the compounds are planned to help select candidates for potential clinical development. This research demonstrates the power of the phenotypic drug discovery approach for neglected tropical diseases.
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Neau P, Hänel H, Lameyre V, Strub-Wourgaft N, Kuykens L. Innovative Partnerships for the Elimination of Human African Trypanosomiasis and the Development of Fexinidazole. Trop Med Infect Dis 2020; 5:tropicalmed5010017. [PMID: 32012658 PMCID: PMC7157581 DOI: 10.3390/tropicalmed5010017] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [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: 12/03/2019] [Revised: 01/08/2020] [Accepted: 01/10/2020] [Indexed: 11/27/2022] Open
Abstract
Human African Trypanosomiasis (HAT or sleeping sickness) is a life-threatening neglected tropical disease that is endemic in 36 sub-Saharan African countries. Until recently, treatment options were limited and hampered by unsatisfactory efficacy, toxicity, and long and cumbersome administration regimens, compounded by infrastructure inadequacies in the remote rural regions worst affected by the disease. Increased funding and awareness of HAT over the past two decades has led to a steady decline in reported cases (<1000 in 2018). Recent drug development strategies have resulted in development of the first all-oral treatment for HAT, fexinidazole. Fexinidazole received European Medicines Agency positive scientific opinion in 2018 and is now incorporated into the WHO interim guidelines as one of the first-line treatments for HAT, allowing lumbar puncture to become non-systematic. Here, we highlight the role of global collaborations in the effort to control HAT and develop new treatments. The long-standing collaboration between the WHO, Sanofi and the Drugs for Neglected Diseases initiative (Geneva, Switzerland) was instrumental for achieving the control and treatment development goals in HAT, whilst at the same time ensuring that efforts were led by national authorities and control programs to leave a legacy of highly trained healthcare workers and improved research and health infrastructure.
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Affiliation(s)
- Philippe Neau
- Sanofi France, 82 avenue Raspail, 94250 Gentilly, France;
- Correspondence:
| | - Heinz Hänel
- Sanofi Deutschland, Industriepark Höchst, Bldg. H831, 65926 Frankfurt am Main, Germany;
| | | | - Nathalie Strub-Wourgaft
- Drugs for Neglected Diseases initiative (DNDi), 15 Chemin Louis-Dunant, 1202 Geneva, Switzerland;
| | - Luc Kuykens
- Sanofi US, 55 Corporate Drive, Bridgewater, NJ 08807, USA;
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P De Koning H. The Drugs of Sleeping Sickness: Their Mechanisms of Action and Resistance, and a Brief History. Trop Med Infect Dis 2020; 5:E14. [PMID: 31963784 PMCID: PMC7157662 DOI: 10.3390/tropicalmed5010014] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [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: 12/19/2019] [Revised: 01/15/2020] [Accepted: 01/16/2020] [Indexed: 12/17/2022] Open
Abstract
With the incidence of sleeping sickness in decline and genuine progress being made towards the WHO goal of eliminating sleeping sickness as a major public health concern, this is a good moment to evaluate the drugs that 'got the job done': their development, their limitations and the resistance that the parasites developed against them. This retrospective looks back on the remarkable story of chemotherapy against trypanosomiasis, a story that goes back to the very origins and conception of chemotherapy in the first years of the 20 century and is still not finished today.
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Affiliation(s)
- Harry P De Koning
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow G12 8TA, UK
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Mudji J, Blum A, Grize L, Wampfler R, Ruf MT, Cnops L, Nickel B, Burri C, Blum J. Gambiense Human African Trypanosomiasis Sequelae after Treatment: A Follow-Up Study 12 Years after Treatment. Trop Med Infect Dis 2020; 5:E10. [PMID: 31940846 DOI: 10.3390/tropicalmed5010010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 01/01/2020] [Accepted: 01/08/2020] [Indexed: 11/16/2022] Open
Abstract
The clinical presentation of Human African Trypanosomiasis (HAT) due to Trypanosoma brucei gambiense is well known, but knowledge on long-term sequelae is limited. In the frame of studies conducted between 2004 and 2005 in the Democratic Republic of the Congo (DRC), the prevalence of HAT related signs and symptoms were evaluated before the start of treatment and at the end of treatment. To explore possible long-term sequelae, the same clinical parameters were assessed in 2017 in 51 first stage and 18 second stage HAT patients. Signs and symptoms 12–13 years after treatment were compared to before and immediately after treatment and to controls matched for sex and age (±5 years). In first stage HAT patients, the prevalence of all signs and symptoms decreased compared to before treatment but were still higher after 12–13 years than immediately at the end of treatment and in the control group. In second stage HAT patients, all HAT-specific findings had continuously decreased to the point where they were in the range of the healthy control group. In a selection of oligosymptomatic first stage HAT patients, no trypanosomes were detected in the blood by microscopic examination or PCR. An oligosymptomatic presentation of HAT due to the persistence of parasites in compartments, where first stage HAT medications do not penetrate, could not be ruled out.
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Seixas J, Atouguia J, Josenando T, Vatunga G, Bilenge CMM, Lutumba P, Burri C. Clinical Study on the Melarsoprol-Related Encephalopathic Syndrome: Risk Factors and HLA Association. Trop Med Infect Dis 2020; 5:E5. [PMID: 31906333 DOI: 10.3390/tropicalmed5010005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 12/23/2019] [Accepted: 12/25/2019] [Indexed: 11/17/2022] Open
Abstract
Melarsoprol administration for the treatment of late-stage human African trypanosomiasis (HAT) is associated with the development of an unpredictable and badly characterized encephalopathic syndrome (ES), probably of immune origin, that kills approximately 50% of those affected. We investigated the characteristics and clinical risk factors for ES, as well as the association between the Human Leukocyte Antigen (HLA) complex and the risk for ES in a case-control study. Late-stage Gambiense HAT patients treated with melarsoprol and developing ES (69 cases) were compared to patients not suffering from the syndrome (207 controls). Patients were enrolled in six HAT treatment centres in Angola and in the Democratic Republic of Congo. Standardized clinical data was obtained from all participants before melarsoprol was initiated. Class I (HLA-A, HLA-B, HLA-Cw) and II (HLA-DR) alleles were determined by PCR-SSOP methods in 62 ES cases and 189 controls. The principal ES pattern consisted in convulsions followed by a coma, whereas ES with exclusively mental changes was not observed. Oedema, bone pain, apathy, and a depressed humour were associated with a higher risk of ES, while abdominal pain, coma, respiratory distress, and a Babinski sign were associated with higher ES-associated mortality. Haplotype C*14/B*15 was associated with an elevated risk for ES (OR: 6.64; p-value: 0.008). Haplotypes A*23/C*14, A*23/B*15 and DR*07/B*58 also showed a weaker association with ES. This result supports the hypothesis that a genetically determined peculiar type of immune response confers susceptibility for ES.
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Pilotte N, Cook DA, Pryce J, Zulch MF, Minetti C, Reimer LJ, Williams SA. Laboratory evaluation of molecular xenomonitoring using mosquito excreta/feces to amplify Plasmodium, Brugia, and Trypanosoma DNA. Gates Open Res 2019; 3:1734. [PMID: 32596646 PMCID: PMC7308644 DOI: 10.12688/gatesopenres.13093.1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [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] [Accepted: 12/16/2019] [Indexed: 03/30/2024] Open
Abstract
Background: Results from an increasing number of studies suggest that mosquito excreta/feces (E/F) testing has considerable potential to serve as a supplement for traditional molecular xenomonitoring techniques. However, as the catalogue of possible use-cases for this methodology expands, and the list of amenable pathogens grows, a number of fundamental methods-based questions remain. Answering these questions is critical to maximizing the utility of this approach and to facilitating its successful implementation as an effective tool for molecular xenomonitoring. Methods: Utilizing E/F produced by mosquitoes or tsetse flies experimentally exposed to Brugia malayi, Plasmodium falciparum, or Trypanosoma brucei brucei, factors such as limits of detection, throughput of testing, adaptability to use with competent- and incompetent-vector species, and effects of additional blood feedings post parasite-exposure were evaluated. Two platforms for the detection of pathogen signal (quantitative real-time PCR and digital PCR [dPCR]) were also compared, with strengths and weaknesses examined for each. Results: Experimental results indicated that high throughput testing is possible when evaluating mosquito E/F for the presence of either B. malayi or P. falciparum from both competent- and incompetent-vector mosquito species. Furthermore, following exposure to pathogen, providing mosquitoes with a second, uninfected bloodmeal did not expand the temporal window for E/F collection during which pathogen detection was possible. However, this collection window did appear longer in E/F collected from tsetse flies following exposure to T. b. brucei. Testing also suggested that dPCR may facilitate detection through its increased sensitivity. Unfortunately, logistical obstacles will likely make the large-scale use of dPCR impractical for this purpose. Conclusions: By examining many E/F testing variables, expansion of this technology to a field-ready platform has become increasingly feasible. However, translation of this methodology from the lab to the field will first require the completion of field-based pilot studies aimed at assessing the efficacy of E/F screening.
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Affiliation(s)
- Nils Pilotte
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, 01063, USA
- Molecular and Cellular Biology Program, University of Massachusetts, Amherst, Massachusetts, 01003, USA
| | - Darren A.N. Cook
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Joseph Pryce
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Michael F. Zulch
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, 01063, USA
| | - Corrado Minetti
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Lisa J. Reimer
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Steven A. Williams
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, 01063, USA
- Molecular and Cellular Biology Program, University of Massachusetts, Amherst, Massachusetts, 01003, USA
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Dozio V, Lejon V, Mumba Ngoyi D, Büscher P, Sanchez JC, Tiberti N. Cerebrospinal Fluid-Derived Microvesicles From Sleeping Sickness Patients Alter Protein Expression in Human Astrocytes. Front Cell Infect Microbiol 2019; 9:391. [PMID: 31824868 PMCID: PMC6879452 DOI: 10.3389/fcimb.2019.00391] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [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: 08/09/2019] [Accepted: 10/30/2019] [Indexed: 12/24/2022] Open
Abstract
Human African trypanosomiasis (HAT) caused by the extracellular protozoon Trypanosoma brucei, is a neglected tropical disease affecting the poorest communities in sub-Saharan Africa. HAT progresses from a hemolymphatic first stage (S1) to a meningo-encephalitic late stage (S2) when parasites reach the central nervous system (CNS), although the existence of an intermediate stage (Int.) has also been proposed. The pathophysiological mechanisms associated with the development of S2 encephalopathy are yet to be fully elucidated. Here we hypothesized that HAT progression toward S2 might be accompanied by an increased release of microvesicles (MVs), sub-micron elements (0.1–1 μm) involved in inflammatory processes and in the determination of the outcome of infections. We studied the morphology of MVs isolated from HAT cerebrospinal fluid (CSF) by transmission electron microscopy (TEM) and used flow cytometry to show that total-MVs and leukocyte derived-CD45+ MVs are significantly increased in concentration in S2 patients' CSF compared to S1 and Int. samples (n = 12 per group). To assess potential biological properties of these MVs, immortalized human astrocytes were exposed, in vitro, to MVs enriched from S1, Int. or S2 CSF. Data-independent acquisition mass spectrometry analyses showed that S2 MVs induced, compared to Int. or S1 MVs, a strong proteome modulation in astrocytes that resembled the one produced by IFN-γ, a key molecule in HAT pathogenesis. Our results indicate that HAT S2 CSF harbors MVs potentially involved in the mechanisms of pathology associated with HAT late stage. Such vesicles might thus represent a new player to consider in future functional studies.
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Affiliation(s)
- Vito Dozio
- Translational Biomarker Group, University of Geneva, Geneva, Switzerland
| | - Veerle Lejon
- Intertryp, Institut de Recherche pour le Développement, CIRAD, University of Montpellier, Montpellier, France
| | - Dieudonné Mumba Ngoyi
- Department of Parasitology, Institut National de Recherche Biomédicale, Kinshasa, Democratic Republic of Congo
| | - Philippe Büscher
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | | | - Natalia Tiberti
- Translational Biomarker Group, University of Geneva, Geneva, Switzerland.,Department of Infectious - Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Verona, Italy
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Wiedemar N, Zwyer M, Zoltner M, Cal M, Field MC, Mäser P. Expression of a specific variant surface glycoprotein has a major impact on suramin sensitivity and endocytosis in Trypanosoma brucei. FASEB Bioadv 2019; 1:595-608. [PMID: 32123811 PMCID: PMC6996322 DOI: 10.1096/fba.2019-00033] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [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: 04/17/2019] [Revised: 04/17/2019] [Accepted: 07/25/2019] [Indexed: 11/11/2022] Open
Abstract
Suramin was introduced into the clinic a century ago and is still used to treat the first stage of acute human sleeping sickness. Due to its size and sixfold negative charge, uptake is mediated through endocytosis and the suramin receptor in trypanosomes is thought to be the invariant surface glycoprotein 75 (ISG75). Nevertheless, we recently identified a variant surface glycoprotein (VSGSur) that confers strong in vitro resistance to suramin in a Trypanosoma brucei rhodesiense line. In this study, we introduced VSGSur into the active bloodstream expression site of a T. b. brucei line. This caused suramin resistance and cross resistance to trypan blue. We quantified the endocytosis of different substrates by flow cytometry and showed that the expression of VSGSur strongly impairs the uptake of low-density lipoprotein (LDL) and transferrin, both imported by receptor-mediated endocytosis. However, bulk endocytosis and endocytosis of the trypanolytic factor were not affected, and the VSGSur -expressors did not exhibit a growth phenotype in the absence of suramin. Knockdown of ISG75 was synergistic with VSGSur expression, indicating that these two proteins are mediating distinct suramin resistance pathways. In conclusion, VSGSur causes suramin resistance in T. brucei bloodstream forms by decreasing specific, receptor-mediated endocytosis pathways.
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Affiliation(s)
- Natalie Wiedemar
- Swiss Tropical and Public Health InstituteBaselSwitzerland
- University of BaselBaselSwitzerland
| | - Michaela Zwyer
- Swiss Tropical and Public Health InstituteBaselSwitzerland
- University of BaselBaselSwitzerland
| | - Martin Zoltner
- School of Life SciencesUniversity of DundeeDundeeUnited Kingdom
| | - Monica Cal
- Swiss Tropical and Public Health InstituteBaselSwitzerland
- University of BaselBaselSwitzerland
| | - Mark C. Field
- School of Life SciencesUniversity of DundeeDundeeUnited Kingdom
| | - Pascal Mäser
- Swiss Tropical and Public Health InstituteBaselSwitzerland
- University of BaselBaselSwitzerland
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Sabiá Júnior EF, Menezes LFS, de Araújo IFS, Schwartz EF. Natural Occurrence in Venomous Arthropods of Antimicrobial Peptides Active against Protozoan Parasites. Toxins (Basel) 2019; 11:E563. [PMID: 31557900 PMCID: PMC6832604 DOI: 10.3390/toxins11100563] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [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: 08/15/2019] [Revised: 08/31/2019] [Accepted: 09/10/2019] [Indexed: 02/07/2023] Open
Abstract
Arthropoda is a phylum of invertebrates that has undergone remarkable evolutionary radiation, with a wide range of venomous animals. Arthropod venom is a complex mixture of molecules and a source of new compounds, including antimicrobial peptides (AMPs). Most AMPs affect membrane integrity and produce lethal pores in microorganisms, including protozoan pathogens, whereas others act on internal targets or by modulation of the host immune system. Protozoan parasites cause some serious life-threatening diseases among millions of people worldwide, mostly affecting the poorest in developing tropical regions. Humans can be infected with protozoan parasites belonging to the genera Trypanosoma, Leishmania, Plasmodium, and Toxoplasma, responsible for Chagas disease, human African trypanosomiasis, leishmaniasis, malaria, and toxoplasmosis. There is not yet any cure or vaccine for these illnesses, and the current antiprotozoal chemotherapeutic compounds are inefficient and toxic and have been in clinical use for decades, which increases drug resistance. In this review, we will present an overview of AMPs, the diverse modes of action of AMPs on protozoan targets, and the prospection of novel AMPs isolated from venomous arthropods with the potential to become novel clinical agents to treat protozoan-borne diseases.
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Affiliation(s)
- Elias Ferreira Sabiá Júnior
- Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade de Brasília, Brasília, DF 70910-900, Brazil.
| | - Luis Felipe Santos Menezes
- Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade de Brasília, Brasília, DF 70910-900, Brazil.
| | - Israel Flor Silva de Araújo
- Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade de Brasília, Brasília, DF 70910-900, Brazil.
| | - Elisabeth Ferroni Schwartz
- Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade de Brasília, Brasília, DF 70910-900, Brazil.
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Kimani NM, Backhaus S, Matasyoh JC, Kaiser M, Herrmann FC, Schmidt TJ, Langer K. Preparation of Sesquiterpene Lactone-Loaded PLA Nanoparticles and Evaluation of Their Antitrypanosomal Activity. Molecules 2019; 24:molecules24112110. [PMID: 31167374 PMCID: PMC6600441 DOI: 10.3390/molecules24112110] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [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: 05/03/2019] [Revised: 05/28/2019] [Accepted: 05/31/2019] [Indexed: 01/08/2023] Open
Abstract
Human African trypanosomiasis (HAT), also commonly known as sleeping sickness, is a neglected tropical disease affecting millions of people in poorly developed regions in sub-Saharan Africa. There is no satisfactory treatment for this infection. The investment necessary to bring new drugs to the market is a big deterrent to drug development, considering that the affected communities form a non-lucrative sector. However, natural products and many sesquiterpene lactones (STLs) in particular are very strong trypanocides. Research and applications of nano-drug delivery systems such as nanoparticles (NPs) have undergone unprecedented growth in the recent past. This is mainly due to the advantages offered by these systems, such as targeted delivery of the drug to the place of action (cell, parasite, etc), sustained release of the drug, increased bioavailability, reduced drug dosage, and reduction of undesired side effects, among others. In this study, the STLs α-santonin, arglabin, schkuhrin II, vernolepin, and eucannabinolide, all trypanocides, were loaded into polylactic acid (PLA) NPs through an emulsification-diffusion method. The NPs were stable, homogenous, and spherical in shape with a rounded knotty depression like a navel orange. The average particle sizes were 202.3, 220.3, 219.5, 216.9, and 226.4 nm for α-santonin, arglabin, schkuhrin II, vernolepin, and eucannabinolide, respectively. The NPs had encapsulation efficiencies of 94.6, 78.1, 76.8, 60.7, and 78.9% for α-santonin, arglabin, schkuhrin II, vernolepin, and eucannabinolide, respectively. The NPs loaded with arglabin, vernolepin, and eucannabinolide exhibited considerable antitrypanosomal activity against Trypanosoma brucei rhodesiense (Tbr) with free drug equivalent IC50 values of 3.67, 1.11 and 3.32 µM, respectively. None of the NP formulations displayed cytotoxicity towards mammalian cells (rat skeletal myoblast cell line L6). These results provide new insights into the possibility of incorporating STLs into nanoparticles, which may provide new options for their formulation in order to develop new drugs against HAT.
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Affiliation(s)
- Njogu M Kimani
- Institute of Pharmaceutical Biology and Phytochemistry (IPBP), University of Muenster, PharmaCampus Corrensstrasse 48, D-48149 Muenster, Germany.
| | - Solveig Backhaus
- Institute of Pharmaceutical Technology and Biopharmacy, University of Muenster, PharmaCampus Corrensstrasse 48, D-48149 Muenster, Germany.
| | - Josphat C Matasyoh
- Department of Chemistry, Egerton University, P.O. Box 536, Egerton 20115, Kenya.
| | - Marcel Kaiser
- Swiss Tropical and Public Health Institute (Swiss TPH), Socinstrasse 57, CH-4051 Basel, Switzerland.
- University of Basel, Petersplatz 1, CH-4003 Basel, Switzerland.
| | - Fabian C Herrmann
- Institute of Pharmaceutical Biology and Phytochemistry (IPBP), University of Muenster, PharmaCampus Corrensstrasse 48, D-48149 Muenster, Germany.
| | - Thomas J Schmidt
- Institute of Pharmaceutical Biology and Phytochemistry (IPBP), University of Muenster, PharmaCampus Corrensstrasse 48, D-48149 Muenster, Germany.
| | - Klaus Langer
- Institute of Pharmaceutical Technology and Biopharmacy, University of Muenster, PharmaCampus Corrensstrasse 48, D-48149 Muenster, Germany.
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Abstract
Trypanosomiasis has been recognized as a scourge in sub-Saharan Africa for centuries. The disease, caused by protozoan parasites of the Trypanosoma genus, is a major cause of mortality and morbidity in animals and man. Human African trypanosomiasis (HAT), or sleeping sickness, results from infections with T. brucei (b.) gambiense or T. b. rhodesiense with T. b. gambiense accounting for over 95% of infections. Historically there have been major epidemics of the infection, followed by periods of relative disease control. As a result of concerted disease surveillance and treatment programmes, implemented over the last two decades, there has been a significant reduction in the number of cases of human disease reported. However, the recent identification of asymptomatic disease carriers gives cause for some concern. The parasites evade the host immune system by switching their surface coat, comprised of variable surface glycoprotein (VSG). In addition, they have evolved a variety of strategies, including the production of serum resistance associated protein (SRA) and T. b. gambiense-specific glycoprotein (TgsGP) to counter host defense molecules. Infection with either disease variant results in an early haemolymphatic-stage followed by a late encephalitic-stage when the parasites migrate into the CNS. The clinical features of HAT are diverse and non-specific with early-stage symptoms common to several infections endemic within sub-Saharan Africa which may result in a delayed or mistaken diagnosis. Migration of the parasites into the CNS marks the onset of late-stage disease. Diverse neurological manifestations can develop accompanied by a neuroinflammatory response, comprised of astrocyte activation, and inflammatory cell infiltration. However, the transition between the early and late-stage is insidious and accurate disease staging, although crucial to optimize chemotherapy, remains problematic with neurological symptoms and neuroinflammatory changes recorded in early-stage infections. Further research is required to develop better diagnostic and staging techniques as well as safer more efficacious drug regimens. Clearer information is also required concerning disease pathogenesis, specifically regarding asymptomatic carriers and the mechanisms employed by the trypanosomes to facilitate progression to the CNS and precipitate late-stage disease. Without progress in these areas it may prove difficult to maintain current control over this historically episodic disease.
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Affiliation(s)
- Peter G. E. Kennedy
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Jean Rodgers
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
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Kimani NM, Matasyoh JC, Kaiser M, Nogueira MS, Trossini GHG, Schmidt TJ. Complementary Quantitative Structure⁻Activity Relationship Models for the Antitrypanosomal Activity of Sesquiterpene Lactones. Int J Mol Sci 2018; 19:ijms19123721. [PMID: 30467296 PMCID: PMC6321053 DOI: 10.3390/ijms19123721] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [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: 10/05/2018] [Revised: 11/17/2018] [Accepted: 11/19/2018] [Indexed: 02/01/2023] Open
Abstract
Three complementary quantitative structure–activity relationship (QSAR) methodologies, namely, regression modeling based on (i) “classical” molecular descriptors, (ii) 3D pharmacophore features, and (iii) 2D molecular holograms (HQSAR) were employed on the antitrypanosomal activity of sesquiterpene lactones (STLs) toward Trypanosoma brucei rhodesiense (Tbr), the causative agent of the East African form of human African trypanosomiasis. In this study, an extension of a previous QSAR study on 69 STLs, models for a much larger and more diverse set of such natural products, now comprising 130 STLs of various structural subclasses, were established. The extended data set comprises a variety of STLs isolated and tested for antitrypanosomal activity within our group and is furthermore enhanced by 12 compounds obtained from literature, which have been tested in the same laboratory under identical conditions. Detailed QSAR analyses yielded models with comparable and good internal and external predictive ability. For a set of compounds as chemically diverse as the one under study, the models exhibited good coefficients of determination (R2) ranging from 0.71 to 0.85, as well as internal (leave-one-out Q2 values ranging from 0.62 to 0.72) and external validation coefficients (P2 values ranging from 0.54 to 0.73). The contributions of the various tested descriptors to the generated models are in good agreement with the results of previous QSAR studies and corroborate the fact that the antitrypanosomal activity of STLs is very much dependent on the presence and relative position of reactive enone groups within the molecular structure but is influenced by their hydrophilic/hydrophobic properties and molecular shape.
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Affiliation(s)
- Njogu M Kimani
- Institute of Pharmaceutical Biology and Phytochemistry (IPBP), University of Muenster, PharmaCampus Corrensstrasse 48, D-48149 Muenster, Germany.
| | - Josphat C Matasyoh
- Department of Chemistry, Egerton University, P.O. Box 536, Egerton 20115, Kenya.
| | - Marcel Kaiser
- Swiss Tropical and Public Health Institute (Swiss TPH), Socinstrasse 57, CH-4051 Basel, Switzerland.
- University of Basel, Petersplatz 1, CH-4003 Basel, Switzerland.
| | - Mauro S Nogueira
- Institute of Pharmaceutical Biology and Phytochemistry (IPBP), University of Muenster, PharmaCampus Corrensstrasse 48, D-48149 Muenster, Germany.
| | - Gustavo H G Trossini
- Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, Av. Lineu Prestes 580, 05508-000 São Paulo, Brazil.
| | - Thomas J Schmidt
- Institute of Pharmaceutical Biology and Phytochemistry (IPBP), University of Muenster, PharmaCampus Corrensstrasse 48, D-48149 Muenster, Germany.
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Monti L, Wang SC, Oukoloff K, Smith AB, Brunden KR, Caffrey CR, Ballatore C. Brain-Penetrant Triazolopyrimidine and Phenylpyrimidine Microtubule Stabilizers as Potential Leads to Treat Human African Trypanosomiasis. ChemMedChem 2018; 13:1751-1754. [PMID: 29969537 DOI: 10.1002/cmdc.201800404] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [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: 06/14/2018] [Indexed: 11/07/2022]
Abstract
In vitro whole-organism screens of Trypanosoma brucei with representative examples of brain-penetrant microtubule (MT)-stabilizing agents identified lethal triazolopyrimidines and phenylpyrimidines with sub-micromolar potency. In mammalian cells, these antiproliferative compounds disrupt MT integrity and decrease total tubulin levels. Their parasiticidal potency, combined with their generally favorable pharmacokinetic properties, which include oral bioavailability and brain penetration, suggest that these compounds are potential leads against human African trypanosomiasis.
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Affiliation(s)
- Ludovica Monti
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - Steven C Wang
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - Killian Oukoloff
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - Amos B Smith
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, 231 South 34th Street, Philadelphia, PA, 19104-6323, USA
| | - Kurt R Brunden
- Center for Neurodegenerative Disease Research, Perelman School of Medicine, University of Pennsylvania, 3600 Spruce Street, Philadelphia, PA, 19104-6323, USA
| | - Conor R Caffrey
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - Carlo Ballatore
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA
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Leaver DJ. Synthesis and Biological Activity of Sterol 14α-Demethylase and Sterol C24-Methyltransferase Inhibitors. Molecules 2018; 23:E1753. [PMID: 30018257 DOI: 10.3390/molecules23071753] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 07/13/2018] [Accepted: 07/15/2018] [Indexed: 11/17/2022] Open
Abstract
Sterol 14α-demethylase (SDM) is essential for sterol biosynthesis and is the primary molecular target for clinical and agricultural antifungals. SDM has been demonstrated to be a valid drug target for antiprotozoal therapies, and much research has been focused on using SDM inhibitors to treat neglected tropical diseases such as human African trypanosomiasis (HAT), Chagas disease, and leishmaniasis. Sterol C24-methyltransferase (24-SMT) introduces the C24-methyl group of ergosterol and is an enzyme found in pathogenic fungi and protozoa but is absent from animals. This difference in sterol metabolism has the potential to be exploited in the development of selective drugs that specifically target 24-SMT of invasive fungi or protozoa without adversely affecting the human or animal host. The synthesis and biological activity of SDM and 24-SMT inhibitors are reviewed herein.
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Abstract
New tools are required to ensure the adequate control of the neglected tropical disease human African trypanosomiasis. Annual reports of infection have recently fallen to fewer than 5000 cases per year; however, current therapies are hard to administer and have safety concerns and, hence, are far from ideal. Trypanosome alternative oxidase is an exciting target for controlling the infection; it is unique to the parasite, and inhibition of this enzyme with the natural product ascofuranone has shown to clear in vivo infections. We report the synthesis and associated structure activity relationships of inhibitors based upon this natural product with correlation to T. b. brucei growth inhibition in an attempt to generate molecules that possess improved physicochemical properties and potential for use as new treatments for human African trypanosomiasis.
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Affiliation(s)
- Ryan A. West
- Sussex Drug Discovery Centre, University of Sussex, Brighton, BN1 9QJ, United Kingdom
| | - Thomas Cunningham
- Sussex Drug Discovery Centre, University of Sussex, Brighton, BN1 9QJ, United Kingdom
| | - Lewis E. Pennicott
- Sussex Drug Discovery Centre, University of Sussex, Brighton, BN1 9QJ, United Kingdom
| | - Srinivasa P. S. Rao
- Novartis Institutes for Tropical Diseases, 5300 Chiron Way, Emeryville, California 94608-2916, United States
| | - Simon E. Ward
- Sussex Drug Discovery Centre, University of Sussex, Brighton, BN1 9QJ, United Kingdom
- Medicines Discovery Institute, Cardiff University, Park Place, Cardiff, CF10 3AT, United Kingdom
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Büscher P, Bart JM, Boelaert M, Bucheton B, Cecchi G, Chitnis N, Courtin D, Figueiredo LM, Franco JR, Grébaut P, Hasker E, Ilboudo H, Jamonneau V, Koffi M, Lejon V, MacLeod A, Masumu J, Matovu E, Mattioli R, Noyes H, Picado A, Rock KS, Rotureau B, Simo G, Thévenon S, Trindade S, Truc P, Van Reet N. Do Cryptic Reservoirs Threaten Gambiense-Sleeping Sickness Elimination? Trends Parasitol 2018; 34:197-207. [PMID: 29396200 PMCID: PMC5840517 DOI: 10.1016/j.pt.2017.11.008] [Citation(s) in RCA: 103] [Impact Index Per Article: 17.2] [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: 10/06/2017] [Revised: 11/18/2017] [Accepted: 11/27/2017] [Indexed: 12/22/2022]
Abstract
Trypanosoma brucei gambiense causes human African trypanosomiasis (HAT). Between 1990 and 2015, almost 440000 cases were reported. Large-scale screening of populations at risk, drug donations, and efforts by national and international stakeholders have brought the epidemic under control with <2200 cases in 2016. The World Health Organization (WHO) has set the goals of gambiense-HAT elimination as a public health problem for 2020, and of interruption of transmission to humans for 2030. Latent human infections and possible animal reservoirs may challenge these goals. It remains largely unknown whether, and to what extend, they have an impact on gambiense-HAT transmission. We argue that a better understanding of the contribution of human and putative animal reservoirs to gambiense-HAT epidemiology is mandatory to inform elimination strategies.
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Affiliation(s)
- Philippe Büscher
- Department of Biomedical Sciences, Institute of Tropical Medicine, Nationalestraat 155, 2000 Antwerp, Belgium.
| | - Jean-Mathieu Bart
- INTERTRYP, IRD, CIRAD, Univ Montpellier, Montpellier, France; Centro Nacional de Medicina Tropical, Instituto de Salud Carlos III, Calle Sinesio Delgado 4, 28029 Madrid, Spain
| | - Marleen Boelaert
- Department of Public Health, Institute of Tropical Medicine, Nationalestraat 155, 2000 Antwerp, Belgium
| | - Bruno Bucheton
- INTERTRYP, IRD, CIRAD, Univ Montpellier, Montpellier, France
| | - Giuliano Cecchi
- Sub-regional Office for Eastern Africa, Food and Agriculture Organization of the United Nations, CMC Road, Bole Sub City, Kebele 12/13, P O Box 5536, Addis Ababa, Ethiopia
| | - Nakul Chitnis
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Socinstrasse 57, Postfach, 4002 Basel, Switzerland; University of Basel, Switzerland
| | - David Courtin
- Université Paris Descartes, Institut de Recherche pour le Développement, Unité MERIT, Mère et enfant face aux infections tropicales, 4 avenue de l'Observatoire, 75006 Paris, France
| | - Luisa M Figueiredo
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Avenida Prof Egas Moniz, 1649-028 Lisboa, Portugal
| | - José-Ramon Franco
- Control of Neglected Tropical Diseases, Innovative and Intensified Disease Management, World Health Organization, Via Appia 20, 1202 Geneva, Switzerland
| | - Pascal Grébaut
- INTERTRYP, IRD, CIRAD, Univ Montpellier, Montpellier, France
| | - Epco Hasker
- Department of Public Health, Institute of Tropical Medicine, Nationalestraat 155, 2000 Antwerp, Belgium
| | - Hamidou Ilboudo
- Institut de Recherche sur les Bases Biologiques de la Lutte Intégrée, Centre International de Recherche-Développement sur l'Élevage en zone Subhumide, 01 BP 454 Bobo-Dioulasso 01, Burkina Faso
| | | | - Mathurin Koffi
- Université Jean Lorougnon Guédé, BP 150 Daloa, Côte d'Ivoire
| | - Veerle Lejon
- INTERTRYP, IRD, CIRAD, Univ Montpellier, Montpellier, France
| | - Annette MacLeod
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Henry Wellcome Building, 464 Bearsden Road, Glasgow, UK
| | - Justin Masumu
- Département de Parasitologie, Institut National de Recherche Biomédicale, Avenue de la Démocratie, BP 1197 Kinshasa 1, République Démocratique du Congo
| | - Enock Matovu
- College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, P O Box 7062 Kampala, Uganda
| | - Raffaele Mattioli
- Animal Production and Health Division, Food and Agriculture Organization of the United Nations, Viale delle Terme di Caracalla, 00153 Rome, Italy
| | - Harry Noyes
- Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
| | - Albert Picado
- Foundation for Innovative New Diagnostics, 9 Chemin des Mines, 1202 Geneva, Switzerland
| | - Kat S Rock
- Zeeman Institute for Systems Biology & Infectious Disease Research, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK
| | - Brice Rotureau
- Trypanosome Transmission Group, Trypanosome Cell Biology Unit, INSERM U1201 and Department of Parasites and Insect Vectors, Institut Pasteur, 25, rue du Docteur Roux, 75015 Paris, France
| | - Gustave Simo
- Department of Biochemistry, Faculty of Science, University of Dschang, P O Box 67 Dschang, Cameroon
| | - Sophie Thévenon
- INTERTRYP, IRD, CIRAD, Univ Montpellier, Montpellier, France; CIRAD, INTERTRYP, Montpellier, France
| | - Sandra Trindade
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Avenida Prof Egas Moniz, 1649-028 Lisboa, Portugal
| | - Philippe Truc
- INTERTRYP, IRD, CIRAD, Univ Montpellier, Montpellier, France
| | - Nick Van Reet
- Department of Biomedical Sciences, Institute of Tropical Medicine, Nationalestraat 155, 2000 Antwerp, Belgium
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Laperchia C, Xu YZ, Mumba Ngoyi D, Cotrufo T, Bentivoglio M. Neural Damage in Experimental Trypanosoma brucei gambiense Infection: Hypothalamic Peptidergic Sleep and Wake-Regulatory Neurons. Front Neuroanat 2018. [PMID: 29535612 PMCID: PMC5835115 DOI: 10.3389/fnana.2018.00013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [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] [Indexed: 01/08/2023] Open
Abstract
Neuron populations of the lateral hypothalamus which synthesize the orexin (OX)/hypocretin or melanin-concentrating hormone (MCH) peptides play crucial, reciprocal roles in regulating wake stability and sleep. The disease human African trypanosomiasis (HAT), also called sleeping sickness, caused by extracellular Trypanosoma brucei (T. b.) parasites, leads to characteristic sleep-wake cycle disruption and narcoleptic-like alterations of the sleep structure. Previous studies have revealed damage of OX and MCH neurons during systemic infection of laboratory rodents with the non-human pathogenic T. b. brucei subspecies. No information is available, however, on these peptidergic neurons after systemic infection with T. b. gambiense, the etiological agent of 97% of HAT cases. The present study was aimed at the investigation of immunohistochemically characterized OX and MCH neurons after T. b. gambiense or T. b. brucei infection of a susceptible rodent, the multimammate mouse, Mastomysnatalensis. Cell counts and evaluation of OX fiber density were performed at 4 and 8 weeks post-infection, when parasites had entered the brain parenchyma from the periphery. A significant decrease of OX neurons (about 44% reduction) and MCH neurons (about 54% reduction) was found in the lateral hypothalamus and perifornical area at 8 weeks in T. b. gambiense-infected M. natalensis. A moderate decrease (21% and 24% reduction, respectively), which did not reach statistical significance, was found after T. b. brucei infection. In two key targets of diencephalic orexinergic innervation, the peri-suprachiasmatic nucleus (SCN) region and the thalamic paraventricular nucleus (PVT), densitometric analyses showed a significant progressive decrease in the density of orexinergic fibers in both infection paradigms, and especially during T. b. gambiense infection. Altogether the findings provide novel information showing that OX and MCH neurons are highly vulnerable to chronic neuroinflammatory signaling caused by the infection of human-pathogenic African trypanosomes.
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Affiliation(s)
- Claudia Laperchia
- Department of Neuroscience Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Yuan-Zhong Xu
- Department of Neuroscience Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Dieudonné Mumba Ngoyi
- Institut National de Recherche Biomédicale (INRB), Kinshasa, Democratic Republic of Congo
| | - Tiziana Cotrufo
- Department of Neuroscience Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Marina Bentivoglio
- Department of Neuroscience Biomedicine and Movement Sciences, University of Verona, Verona, Italy.,National Institute of Neuroscience (INN), Verona Unit, Verona, Italy
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Tesoriero C, Xu YZ, Mumba Ngoyi D, Bentivoglio M. Neural Damage in Experimental Trypanosoma brucei gambiense Infection: The Suprachiasmatic Nucleus. Front Neuroanat 2018; 12:6. [PMID: 29491832 PMCID: PMC5817918 DOI: 10.3389/fnana.2018.00006] [Citation(s) in RCA: 10] [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: 11/09/2017] [Accepted: 01/12/2018] [Indexed: 01/01/2023] Open
Abstract
Trypanosoma brucei (T. b.) gambiense is the parasite subspecies responsible for most reported cases of human African trypanosomiasis (HAT) or sleeping sickness. This severe infection leads to characteristic disruption of the sleep-wake cycle, recalling attention on the circadian timing system. Most animal models of the disease have been hitherto based on infection of laboratory rodents with the T. b. brucei subspecies, which is not infectious to humans. In these animal models, functional, rather than structural, alterations of the master circadian pacemaker, the hypothalamic suprachiasmatic nucleus (SCN), have been reported. Information on the SCN after infection with the human pathogenic T. b. gambiense is instead lacking. The present study was aimed at the examination of the SCN after T. b. gambiense infection of a susceptible rodent, the multimammate mouse, Mastomys natalensis, compared with T. b. brucei infection of the same host species. The animals were examined at 4 and 8 weeks post-infection, when parasites (T. b. gambiense or T. b. brucei) were detected in the brain parenchyma, indicating that the disease was in the encephalitic stage. Neuron and astrocyte changes were examined with Nissl staining, immunophenotyping and quantitative analyses. Interestingly, significant neuronal loss (about 30% reduction) was documented in the SCN during the progression of T. b. gambiense infection. No significant neuronal density changes were found in the SCN of T. b. brucei-infected animals. Neuronal cell counts in the hippocampal dentate gyrus of T. b. gambiense-infected M. natalensis did not point out significant changes, indicating that no widespread neuron loss had occurred in the brain. Marked activation of astrocytes was detected in the SCN after both T. b. gambiense and T. b. brucei infections. Altogether the findings reveal that neurons of the biological clock are highly susceptible to the infection caused by human pathogenic African trypanosomes, which have the capacity to cause permanent partial damage of this structure.
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Affiliation(s)
- Chiara Tesoriero
- Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Yuan-Zhong Xu
- Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Dieudonné Mumba Ngoyi
- Institut National de Recherche Biomedicale (INRB), Kinshasa, Democratic Republic of Congo
| | - Marina Bentivoglio
- Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.,National Institute of Neuroscience (INN), Verona Unit, Verona, Italy
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