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Ungogo MA, de Koning HP. Drug resistance in animal trypanosomiases: Epidemiology, mechanisms and control strategies. Int J Parasitol Drugs Drug Resist 2024; 25:100533. [PMID: 38555795 PMCID: PMC10990905 DOI: 10.1016/j.ijpddr.2024.100533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 03/13/2024] [Accepted: 03/15/2024] [Indexed: 04/02/2024]
Abstract
Animal trypanosomiasis (AT) is a complex of veterinary diseases known under various names such as nagana, surra, dourine and mal de caderas, depending on the country, the infecting trypanosome species and the host. AT is caused by parasites of the genus Trypanosoma, and the main species infecting domesticated animals are T. brucei brucei, T. b. rhodesiense, T. congolense, T. simiae, T. vivax, T. evansi and T. equiperdum. AT transmission, again depending on species, is through tsetse flies or common Stomoxys and tabanid flies or through copulation. Therefore, the geographical spread of all forms of AT together is not restricted to the habitat of a single vector like the tsetse fly and currently includes almost all of Africa, and most of South America and Asia. The disease is a threat to millions of companion and farm animals in these regions, creating a financial burden in the billions of dollars to developing economies as well as serious impacts on livestock rearing and food production. Despite the scale of these impacts, control of AT is neglected and under-resourced, with diagnosis and treatments being woefully inadequate and not improving for decades. As a result, neither the incidence of the disease, nor the effectiveness of treatment is documented in most endemic countries, although it is clear that there are serious issues of resistance to the few old drugs that are available. In this review we particularly look at the drugs, their application to the various forms of AT, and their mechanisms of action and resistance. We also discuss the spread of veterinary trypanocide resistance and its drivers, and highlight current and future strategies to combat it.
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Affiliation(s)
- Marzuq A Ungogo
- The Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, United Kingdom; School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Harry P de Koning
- School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom.
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2
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Oaikhena EE, Yahaya UA, Abdulsalami SM, Egbe NL, Adeyemi MM, Ungogo MA, Ebiloma GU, Zoiku FK, Fordjour PA, Elati HAA, Quashie NB, Igoli JO, Gray AI, Lawson C, Ferro VA, de Koning HP. The activities of suaveolol and other compounds from Hyptis suaveolens and Momordica charantia against the aetiological agents of African trypanosomiasis, leishmaniasis and malaria. Exp Parasitol 2024; 263-264:108807. [PMID: 39043327 DOI: 10.1016/j.exppara.2024.108807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 05/24/2024] [Accepted: 07/20/2024] [Indexed: 07/25/2024]
Abstract
African trypanosomiasis and malaria are among the most severe health challenges to humans and livestock in Africa and new drugs are needed. Leaves of Hyptis suaveolens Kuntze (Lamiaceae) and Momordica charantia L. (Cucurbitaceae) were extracted with hexane, ethyl acetate, and then methanol, and subjected to silica gel column chromatography. Structures of six isolated compounds were elucidated through NMR and HR-EIMS spectrometry. Callistrisic acid, dehydroabietinol, suaveolic acid, suaveolol, and a mixture of suaveolol and suaveolic acid (SSA) were obtained from H. suaveolens, while karavilagenin D and momordicin I acetate were obtained from M. charantia. The isolated biomolecules were tested against trypomastigotes of Trypanosoma brucei brucei and T. congolense, and against Plasmodium falciparum. The most promising EC50 values were obtained for the purified suaveolol fraction, at 2.71 ± 0.36 μg/mL, and SSA, exhibiting an EC50 of 1.56 ± 0.17 μg/mL against T. b. brucei trypomastigotes. Suaveolic acid had low activity against T. b. brucei but displayed moderate activity against T. congolense trypomastigotes at 11.1 ± 0.5 μg/mL. Suaveolol and SSA were also tested against T. evansi, T. equiperdum, Leishmania major and L. mexicana but the antileishmanial activity was low. Neither of the active compounds, nor the mixture of the two, displayed any cytotoxic effect on human foreskin fibroblast (HFF) cells at even the highest concentration tested, being 200 μg/mL. We conclude that suaveolol and its mixture possessed significant and selective trypanocidal activity.
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Affiliation(s)
- Enimie E Oaikhena
- Department of Biotechnology, Nigerian Defence Academy, PMB 2109, Kaduna, Kaduna State, Nigeria
| | - Umar A Yahaya
- Department of Biological Sciences, Nigerian Defence Academy, PMB 2109, Kaduna, Kaduna State, Nigeria
| | - Sani M Abdulsalami
- Department of Biotechnology, Nigerian Defence Academy, PMB 2109, Kaduna, Kaduna State, Nigeria
| | - Nkechi L Egbe
- Department of Biotechnology, Nigerian Defence Academy, PMB 2109, Kaduna, Kaduna State, Nigeria
| | - Modupe M Adeyemi
- Department of Chemistry, Nigerian Defence Academy, Kaduna, Kaduna State, Nigeria
| | - Marzuq A Ungogo
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, EH8 PYL, UK
| | - Godwin U Ebiloma
- School of Science, Engineering & Environment, University of Salford, M5 4NT, Manchester, UK
| | - Felix K Zoiku
- Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Prince A Fordjour
- Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Hamza A A Elati
- School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK; Department of Pharmacology and Toxicology, Pharmacy College, University of Elmergib, Al Khums, Libya
| | - Neils B Quashie
- West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Ghana; Centre for Tropical Clinical Pharmacology and Therapeutics, University of Ghana Medical School, Ghana
| | - John O Igoli
- Department of Chemistry, Joseph Sarwuan Tarka University, PMB 2373, Makurdi, Benue State, Nigeria; Strathclyde Institute of Pharmacy and Biomedical Science, University of Strathclyde, Glasgow, G4 0RE, UK
| | - Alexander I Gray
- Strathclyde Institute of Pharmacy and Biomedical Science, University of Strathclyde, Glasgow, G4 0RE, UK
| | - Christopher Lawson
- Strathclyde Institute of Pharmacy and Biomedical Science, University of Strathclyde, Glasgow, G4 0RE, UK
| | - Valerie A Ferro
- Strathclyde Institute of Pharmacy and Biomedical Science, University of Strathclyde, Glasgow, G4 0RE, UK
| | - Harry P de Koning
- School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
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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] [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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Venturelli A, Tagliazucchi L, Lima C, Venuti F, Malpezzi G, Magoulas GE, Santarem N, Calogeropoulou T, Cordeiro-da-Silva A, Costi MP. Current Treatments to Control African Trypanosomiasis and One Health Perspective. Microorganisms 2022; 10:microorganisms10071298. [PMID: 35889018 PMCID: PMC9321528 DOI: 10.3390/microorganisms10071298] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 06/10/2022] [Accepted: 06/20/2022] [Indexed: 02/01/2023] Open
Abstract
Human African Trypanosomiasis (HAT, sleeping sickness) and Animal African Trypanosomiasis (AAT) are neglected tropical diseases generally caused by the same etiological agent, Trypanosoma brucei. Despite important advances in the reduction or disappearance of HAT cases, AAT represents a risky reservoir of the infections. There is a strong need to control AAT, as is claimed by the European Commission in a recent document on the reservation of antimicrobials for human use. Control of AAT is considered part of the One Health approach established by the FAO program against African Trypanosomiasis. Under the umbrella of the One Health concepts, in this work, by analyzing the pharmacological properties of the therapeutic options against Trypanosoma brucei spp., we underline the need for clearer and more defined guidelines in the employment of drugs designed for HAT and AAT. Essential requirements are addressed to meet the challenge of drug use and drug resistance development. This approach shall avoid inter-species cross-resistance phenomena and retain drugs therapeutic activity.
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Affiliation(s)
- Alberto Venturelli
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy; (A.V.); (L.T.); (F.V.); (G.M.)
| | - Lorenzo Tagliazucchi
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy; (A.V.); (L.T.); (F.V.); (G.M.)
- Doctorate School in Clinical and Experimental Medicine (CEM), University of Modena and Reggio Emilia, 41125 Modena, Italy
| | - Clara Lima
- Host-Parasite Interactions Group, Institute of Research and Innovation in Health, University of Porto, 4099-002 Porto, Portugal; (C.L.); (N.S.); (A.C.-d.-S.)
- Department of Biological Sciences, Faculty of Pharmacy, University of Porto, 4099-002 Porto, Portugal
| | - Federica Venuti
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy; (A.V.); (L.T.); (F.V.); (G.M.)
| | - Giulia Malpezzi
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy; (A.V.); (L.T.); (F.V.); (G.M.)
| | - George E. Magoulas
- Institute of Chemical Biology, National Hellenic Research Foundation, 11635 Athens, Greece; (G.E.M.); (T.C.)
| | - Nuno Santarem
- Host-Parasite Interactions Group, Institute of Research and Innovation in Health, University of Porto, 4099-002 Porto, Portugal; (C.L.); (N.S.); (A.C.-d.-S.)
- Department of Biological Sciences, Faculty of Pharmacy, University of Porto, 4099-002 Porto, Portugal
| | - Theodora Calogeropoulou
- Institute of Chemical Biology, National Hellenic Research Foundation, 11635 Athens, Greece; (G.E.M.); (T.C.)
| | - Anabela Cordeiro-da-Silva
- Host-Parasite Interactions Group, Institute of Research and Innovation in Health, University of Porto, 4099-002 Porto, Portugal; (C.L.); (N.S.); (A.C.-d.-S.)
- Department of Biological Sciences, Faculty of Pharmacy, University of Porto, 4099-002 Porto, Portugal
| | - Maria Paola Costi
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy; (A.V.); (L.T.); (F.V.); (G.M.)
- Correspondence:
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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] [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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6
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Hulpia F, Bouton J, Campagnaro GD, Alfayez IA, Mabille D, Maes L, de Koning HP, Caljon G, Van Calenbergh S. C6-O-alkylated 7-deazainosine nucleoside analogues: Discovery of potent and selective anti-sleeping sickness agents. Eur J Med Chem 2020; 188:112018. [PMID: 31931339 DOI: 10.1016/j.ejmech.2019.112018] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 12/27/2019] [Accepted: 12/27/2019] [Indexed: 01/02/2023]
Abstract
African trypanosomiasis, a deadly infectious disease caused by the protozoan Trypanosoma brucei spp., is spread to new hosts by bites of infected tsetse flies. Currently approved therapies all have their specific drawbacks, prompting a search for novel therapeutic agents. T. brucei lacks the enzymes necessary to forge the purine ring from amino acid precursors, rendering them dependent on the uptake and interconversion of host purines. This dependency renders analogues of purines and corresponding nucleosides an interesting source of potential anti-T. brucei agents. In this study, we synthesized and evaluated a series of 7-substituted 7-deazainosine derivatives and found that 6-O-alkylated analogues in particular showed highly promising in vitro activity with EC50 values in the mid-nanomolar range. SAR investigation of the O-alkyl chain showed that antitrypanosomal activity increased, and also cytotoxicity, with alkyl chain length, at least in the linear alkyl chain series. However, this could be attenuated by introducing a terminal branch point, resulting in the highly potent and selective analogues, 36, 37 and 38. No resistance related to transporter-mediated uptake could be identified, earmarking several of these analogues for further in vivo follow-up studies.
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Affiliation(s)
- Fabian Hulpia
- Laboratory for Medicinal Chemistry (Campus Heymans), Ghent University, Ottergemsesteenweg 460, B-9000, Gent, Belgium
| | - Jakob Bouton
- Laboratory for Medicinal Chemistry (Campus Heymans), Ghent University, Ottergemsesteenweg 460, B-9000, Gent, Belgium
| | - Gustavo D Campagnaro
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA, United Kingdom
| | - Ibrahim A Alfayez
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA, United Kingdom
| | - Dorien Mabille
- Laboratory of Microbiology, Parasitology and Hygiene, University of Antwerp, Universiteitsplein 1 (S7), B-2610, Wilrijk, Belgium
| | - Louis Maes
- Laboratory of Microbiology, Parasitology and Hygiene, University of Antwerp, Universiteitsplein 1 (S7), B-2610, Wilrijk, Belgium
| | - Harry P de Koning
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA, United Kingdom
| | - Guy Caljon
- Laboratory of Microbiology, Parasitology and Hygiene, University of Antwerp, Universiteitsplein 1 (S7), B-2610, Wilrijk, Belgium
| | - Serge Van Calenbergh
- Laboratory for Medicinal Chemistry (Campus Heymans), Ghent University, Ottergemsesteenweg 460, B-9000, Gent, Belgium.
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7
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Melarsoprol Resistance in African Trypanosomiasis. Trends Parasitol 2018; 34:481-492. [DOI: 10.1016/j.pt.2018.04.002] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 04/03/2018] [Accepted: 04/04/2018] [Indexed: 01/06/2023]
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Abstract
Pathogenic animal trypanosomes affecting livestock have represented a major constraint to agricultural development in Africa for centuries, and their negative economic impact is increasing in South America and Asia. Chemotherapy and chemoprophylaxis represent the main means of control. However, research into new trypanocides has remained inadequate for decades, leading to a situation where the few compounds available are losing efficacy due to the emergence of drug-resistant parasites. In this review, we provide a comprehensive overview of the current options available for the treatment and prophylaxis of the animal trypanosomiases, with a special focus on the problem of resistance. The key issues surrounding the main economically important animal trypanosome species and the diseases they cause are also presented. As new investment becomes available to develop improved tools to control the animal trypanosomiases, we stress that efforts should be directed towards a better understanding of the biology of the relevant parasite species and strains, to identify new drug targets and interrogate resistance mechanisms.
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Abstract
Eukaryotic microbial pathogens are major contributors to illness and death globally. Although much of their impact can be controlled by drug therapy as with prokaryotic microorganisms, the emergence of drug resistance has threatened these treatment efforts. Here, we discuss the challenges posed by eukaryotic microbial pathogens and how these are similar to, or differ from, the challenges of prokaryotic antibiotic resistance. The therapies used for several major eukaryotic microorganisms are then detailed, and the mechanisms that they have evolved to overcome these therapies are described. The rapid emergence of resistance and the restricted pipeline of new drug therapies pose considerable risks to global health and are particularly acute in the developing world. Nonetheless, we detail how the integration of new technology, biological understanding, epidemiology and evolutionary analysis can help sustain existing therapies, anticipate the emergence of resistance or optimize the deployment of new therapies.
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Affiliation(s)
- Alan H. Fairlamb
- Dundee Drug Discovery Unit, Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Neil A. R. Gow
- Aberdeen Fungal Group, Wellcome Trust Strategic Award in Medical Mycology and Fungal Immunology, School of Medical Sciences, Institute of Medical Sciences, Foresterhill, University of Aberdeen, Aberdeen AB25 2ZD, UK
| | - Keith R. Matthews
- Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Andrew P. Waters
- Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, College of Medical and Veterinary Life Sciences, University of Glasgow, Glasgow G12 8TA, UK
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Graf FE, Baker N, Munday JC, de Koning HP, Horn D, Mäser P. Chimerization at the AQP2-AQP3 locus is the genetic basis of melarsoprol-pentamidine cross-resistance in clinical Trypanosoma brucei gambiense isolates. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2015; 5:65-8. [PMID: 26042196 PMCID: PMC4443405 DOI: 10.1016/j.ijpddr.2015.04.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Revised: 04/28/2015] [Accepted: 04/29/2015] [Indexed: 01/12/2023]
Abstract
Expression of AQP2 restores drug susceptibility in a resistant Trypanosoma brucei gambiense isolate. The AQP2/3 chimera from the resistant isolate does not complement AQP2 deletion. Hence AQP2/3 chimerization accompanied by loss of AQP2 is the cause of drug resistance.
Aquaglyceroporin-2 is a known determinant of melarsoprol–pentamidine cross-resistance in Trypanosoma brucei brucei laboratory strains. Recently, chimerization at the AQP2–AQP3 tandem locus was described from melarsoprol–pentamidine cross-resistant Trypanosoma brucei gambiense isolates from sleeping sickness patients in the Democratic Republic of the Congo. Here, we demonstrate that reintroduction of wild-type AQP2 into one of these isolates fully restores drug susceptibility while expression of the chimeric AQP2/3 gene in aqp2–aqp3 null T. b. brucei does not. This proves that AQP2–AQP3 chimerization is the cause of melarsoprol–pentamidine cross-resistance in the T. b. gambiense isolates.
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Affiliation(s)
- Fabrice E Graf
- Swiss Tropical and Public Health Institute, CH-4051 Basel, Switzerland ; University of Basel, CH-4000 Basel, Switzerland
| | - Nicola Baker
- Biological Chemistry & Drug Discovery, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
| | - Jane C Munday
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, G12 8TA, UK
| | - Harry P de Koning
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, G12 8TA, UK
| | - David Horn
- Biological Chemistry & Drug Discovery, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
| | - Pascal Mäser
- Swiss Tropical and Public Health Institute, CH-4051 Basel, Switzerland ; University of Basel, CH-4000 Basel, Switzerland
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11
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Munday JC, Tagoe DNA, Eze AA, Krezdorn JAM, Rojas López KE, Alkhaldi AAM, McDonald F, Still J, Alzahrani KJ, Settimo L, De Koning HP. Functional analysis of drug resistance-associated mutations in the Trypanosoma brucei adenosine transporter 1 (TbAT1) and the proposal of a structural model for the protein. Mol Microbiol 2015; 96:887-900. [PMID: 25708978 PMCID: PMC4755147 DOI: 10.1111/mmi.12979] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/21/2015] [Indexed: 02/01/2023]
Abstract
The Trypanosoma brucei aminopurine transporter P2/TbAT1 has long been implicated in the transport of, and resistance to, the diamidine and melaminophenyl arsenical classes of drugs that form the backbone of the pharmacopoeia against African trypanosomiasis. Genetic alterations including deletions and single nucleotide polymorphisms (SNPs) have been observed in numerous strains and clinical isolates. Here, we systematically investigate each reported mutation and assess their effects on transporter function after expression in a tbat1(-/-) T. brucei line. Out of a set of six reported SNPs from a reported 'resistance allele', none significantly impaired sensitivity to pentamidine, diminazene or melarsoprol, relative to the TbAT1-WT allele, although several combinations, and the deletion of the codon for residue F316, resulted in highly significant impairment. These combinations of SNPs, and ΔF316, also strongly impaired the uptake of [(3)H]-adenosine and [(3)H]-diminazene, identical to the tbat1(-/-) control. The TbAT1 protein model predicted that residues F19, D140 and F316 interact with the substrate of the transporter. Mutation of D140 to alanine resulted in an inactive transporter, whereas the mutation F19A produced a transporter with a slightly increased affinity for [(3)H]-diminazene but reduced the uptake rate. The results presented here validate earlier hypotheses of drug binding motifs for TbAT1.
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Affiliation(s)
- Jane C Munday
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA, UK
- Wellcome Trust Centre for Molecular Parasitology, University of Glasgow, Glasgow, UK
| | - Daniel N A Tagoe
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA, UK
- Department of Laboratory Technology, University of Cape Coast, Cape Coast, Ghana
| | - Anthonius A Eze
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA, UK
- Department of Medical Biochemistry, College of Medicine, University of Nigeria, Enugu Campus, Enugu, Nigeria
| | - Jessica A M Krezdorn
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA, UK
| | - Karla E Rojas López
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA, UK
| | - Abdulsalam A M Alkhaldi
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA, UK
- Department of Biology, College of Science, Aljouf University, Sakaka, Saudi Arabia
| | - Fiona McDonald
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA, UK
| | - Jennifer Still
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA, UK
| | - Khalid J Alzahrani
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA, UK
- Faculty of Medical Sciences, Taif University, Taif, Saudi Arabia
| | - Luca Settimo
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA, UK
- Department of Chemistry and Chemical Biology, 417 Egan Research Center, Northeastern University, 360 Huntington Avenue, Boston, MA, 02115, USA
| | - Harry P De Koning
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA, UK
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Graf FE, Ludin P, Wenzler T, Kaiser M, Brun R, Pyana PP, Büscher P, de Koning HP, Horn D, Mäser P. Aquaporin 2 mutations in Trypanosoma brucei gambiense field isolates correlate with decreased susceptibility to pentamidine and melarsoprol. PLoS Negl Trop Dis 2013; 7:e2475. [PMID: 24130910 PMCID: PMC3794916 DOI: 10.1371/journal.pntd.0002475] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Accepted: 08/28/2013] [Indexed: 12/29/2022] Open
Abstract
The predominant mechanism of drug resistance in African trypanosomes is decreased drug uptake due to loss-of-function mutations in the genes for the transporters that mediate drug import. The role of transporters as determinants of drug susceptibility is well documented from laboratory-selected Trypanosoma brucei mutants. But clinical isolates, especially of T. b. gambiense, are less amenable to experimental investigation since they do not readily grow in culture without prior adaptation. Here we analyze a selected panel of 16 T. brucei ssp. field isolates that (i) have been adapted to axenic in vitro cultivation and (ii) mostly stem from treatment-refractory cases. For each isolate, we quantify the sensitivity to melarsoprol, pentamidine, and diminazene, and sequence the genomic loci of the transporter genes TbAT1 and TbAQP2. The former encodes the well-characterized aminopurine permease P2 which transports several trypanocides including melarsoprol, pentamidine, and diminazene. We find that diminazene-resistant field isolates of T. b. brucei and T. b. rhodesiense carry the same set of point mutations in TbAT1 that was previously described from lab mutants. Aquaglyceroporin 2 has only recently been identified as a second transporter involved in melarsoprol/pentamidine cross-resistance. Here we describe two different kinds of TbAQP2 mutations found in T. b. gambiense field isolates: simple loss of TbAQP2, or loss of wild-type TbAQP2 allele combined with the formation of a novel type of TbAQP2/3 chimera. The identified mutant T. b. gambiense are 40- to 50-fold less sensitive to pentamidine and 3- to 5-times less sensitive to melarsoprol than the reference isolates. We thus demonstrate for the first time that rearrangements of the TbAQP2/TbAQP3 locus accompanied by TbAQP2 gene loss also occur in the field, and that the T. b. gambiense carrying such mutations correlate with a significantly reduced susceptibility to pentamidine and melarsoprol. Human African Trypanosomiasis, or sleeping sickness, is a fatal disease restricted to sub-Saharan Africa, caused by Trypanosoma brucei gambiense and T. b. rhodesiense. The treatment relies on chemotherapy exclusively. Drug resistance in T. brucei was investigated mainly in laboratory-selected lines and found to be linked to mutations in transporters. The adenosine transporter TbAT1 and the aquaglyceroporin TbAQP2 have been implicated in sensitivity to melarsoprol and pentamidine. Mutations in these transporters rendered trypanosomes less susceptible to either drug. Here we analyze T. brucei isolates from the field, focusing on isolates from patients where melarsoprol treatment has failed. We genotype those isolates to test for mutations in TbAQP2 or TbAT1, and phenotype for sensitivity to pentamidine and melarsoprol. Six T. b. gambiense isolates were found to carry mutations in TbAQP2. These isolates stemmed from relapse patients and exhibited significantly reduced sensitivity to pentamidine and melarsoprol as determined in cell culture. These findings indicate that mutations in TbAQP2 are present in the field, correlate with loss of sensitivity to pentamidine and melarsoprol, and might be responsible for melarsoprol treatment failures.
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Affiliation(s)
- Fabrice E. Graf
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Philipp Ludin
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Tanja Wenzler
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Marcel Kaiser
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Reto Brun
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Patient Pati Pyana
- Institut National de Recherche Biomédicale, Kinshasa-Gombe, Democratic Republic of the Congo
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Philippe Büscher
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Harry P. de Koning
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - David Horn
- Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Pascal Mäser
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
- * E-mail:
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Baker N, de Koning HP, Mäser P, Horn D. Drug resistance in African trypanosomiasis: the melarsoprol and pentamidine story. Trends Parasitol 2013; 29:110-8. [PMID: 23375541 PMCID: PMC3831158 DOI: 10.1016/j.pt.2012.12.005] [Citation(s) in RCA: 170] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Revised: 12/16/2012] [Accepted: 12/17/2012] [Indexed: 01/07/2023]
Abstract
Melarsoprol and pentamidine represent the two main classes of drugs, the arsenicals and diamidines, historically used to treat the diseases caused by African trypanosomes: sleeping sickness in humans and Nagana in livestock. Cross-resistance to these drugs was first observed over 60 years ago and remains the only example of cross-resistance among sleeping sickness therapies. A Trypanosoma brucei adenosine transporter is well known for its role in the uptake of both drugs. More recently, aquaglyceroporin 2 (AQP2) loss of function was linked to melarsoprol-pentamidine cross-resistance. AQP2, a channel that appears to facilitate drug accumulation, may also be linked to clinical cases of resistance. Here, we review these findings and consider some new questions as well as future prospects for tackling the devastating diseases caused by these parasites.
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Affiliation(s)
- Nicola Baker
- London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Harry P. de Koning
- University of Glasgow, Institute of Infection, Immunity and Inflammation, Sir Graeme Davies Building, 120 University Place, Glasgow, G12 8TA, Scotland
| | - Pascal Mäser
- Swiss Tropical and Public Health Institute, Socinstr. 57, 4051 Basel, Switzerland
- University of Basel, Petersplatz 1, 4003 Basel, Switzerland
| | - David Horn
- London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
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Barrett MP, Vincent IM, Burchmore RJS, Kazibwe AJN, Matovu E. Drug resistance in human African trypanosomiasis. Future Microbiol 2011; 6:1037-47. [DOI: 10.2217/fmb.11.88] [Citation(s) in RCA: 108] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Human African trypanosomiasis or ‘sleeping sickness’ is a neglected tropical disease caused by the parasite Trypanosoma brucei. A decade of intense international cooperation has brought the incidence to fewer than 10,000 reported cases per annum with anti-trypanosomal drugs, particularly against stage 2 disease where the CNS is involved, being central to control. Treatment failures with melarsoprol started to appear in the 1990s and their incidence has risen sharply in many foci. Loss of plasma membrane transporters involved in drug uptake, particularly the P2 aminopurine transporter and also a transporter termed the high affinity pentamidine transporter, relate to melarsoprol resistance selected in the laboratory. The same two transporters are also responsible for the uptake of the stage 1 drug pentamidine and, to varying extents, other diamidines. However, reports of treatment failures with pentamidine have been rare from the field. Eflornithine (difluoromethylornithine) has replaced melarsoprol as first-line treatment in many regions. However, a need for protracted and complicated drug dosing regimens slowed widespread implementation of eflornithine monotherapy. A combination of eflornithine with nifurtimox substantially decreases the required dose and duration of eflornithine administration and this nifurtimox-eflornithine combination therapy has enjoyed rapid implementation. Unfortunately, selection of resistance to eflornithine in the laboratory is relatively easy (through loss of an amino acid transporter believed to be involved in its uptake), as is selection of resistance to nifurtimox. The first anecdotal reports of treatment failures with eflornithine monotherapy are emerging from some foci. The possibility that parasites resistant to melarsoprol on the one hand, and eflornithine on the other, are present in the field indicates that genes capable of conferring drug resistance to both drugs are in circulation. If new drugs, that act in ways that will not render them susceptible to resistance mechanisms already in circulation do not appear soon, there is also a risk that the current downward trend in Human African trypanosomiasis prevalence will be reversed and, as has happened in the past, the disease will become resurgent, only this time in a form that resists available drugs.
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Affiliation(s)
| | - Isabel M Vincent
- Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity & Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, Scotland
| | - Richard JS Burchmore
- Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity & Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, Scotland
| | - Anne JN Kazibwe
- Makerere University School of Veterinary Medicine, Kampala, Uganda
| | - Enock Matovu
- Makerere University School of Veterinary Medicine, Kampala, Uganda
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