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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] [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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Ndungu K, Thuita J, Murilla G, Kagira J, Auma J, Mireji P, Ngae G, Okumu P, Gitonga P, Guya S, Mdachi R. The pathogenicity of blood stream and central nervous system forms of Trypanosoma brucei rhodesiense trypanosomes in laboratory mice: a comparative study. F1000Res 2023; 11:260. [PMID: 38162635 PMCID: PMC10755267 DOI: 10.12688/f1000research.75518.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/01/2023] [Indexed: 01/03/2024] Open
Abstract
Background: Human African trypanosomiasis (HAT) develops in two stages namely early stage when trypanosomes are found in the blood and late stage when trypanosomes are found in the central nervous system (CNS). The two environments are different with CNS environment reported as being hostile to the trypanosomes than the blood environment. The clinical symptoms manifested by the disease in the two environments are different. Information on whether blood stream are pathologically different from CNS trypanosomes is lacking. This study undertook to compare the inter-isolate pathological differences caused by bloodstream forms (BSF) and central nervous system (CNS) of five Trypanosoma brucei rhodesiense ( Tbr) isolates in Swiss white mice. Methods: Donor mice infected with each of the five isolates were euthanized at 21 days post infection (DPI) for recovery of BSF trypanosomes in heart blood and CNS trypanosomes in brain supernatants. Groups of Swiss white mice (n = 10) were then infected with BSF or CNS forms of each isolate and monitored for parasitaemia, packed cell volume (PCV), body weight, survivorship, trypanosome length, gross and histopathology characteristics. Results: Amplification of SRA gene prior to trypanosome morphology and pathogenicity studies confirmed all isolates as T. b. rhodesiense. At 21 DPI, CNS trypanosomes were predominantly long slender (LS) while BSF were a mixture of short stumpy and intermediate forms. The density of BSF trypanosomes was on average 2-3 log-scales greater than that of CNS trypanosomes with isolate KETRI 2656 having the highest CNS trypanosome density. Conclusions: The pathogenicity study revealed clear differences in the virulence/pathogenicity of the five (5) isolates but no distinct and consistent differences between CNS and BSF forms of the same isolate. We also identified KETRI 2656 as a suitable isolate for acute menigo- encephalitic studies.
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Affiliation(s)
- Kariuki Ndungu
- Biochemistry, Kenya Agricultural and Livestock Research Organization, Nairobi, P.O. Box 362 -00902, Kenya
| | - John Thuita
- Animal Science, Meru University of Science and Technology, Meru, P.O Box, 972-60200, Kenya
| | - Grace Murilla
- Administration, KAG East University, Nairobi, P.O.BOX 46328-00100, Kenya
| | - John Kagira
- Animal Science, Jomo Keyatta University of Science and Technology, Nairobi, P.O. Box 62000–00200, Kenya
| | - Joanna Auma
- Biochemistry, Kenya Agricultural and Livestock Research Organization, Nairobi, P.O. Box 362 -00902, Kenya
| | - Paul Mireji
- Bioinformatics, Centre for Geographic Medicine Research, Kilifi, P. O. Box 428-80108, Kenya
| | - Geoffrey Ngae
- Food Crops Research Institute, Kenya Agricultural and Livestock Research Organization, Nairobi, P. O. Box 30148-00200, Kenya
| | - Paul Okumu
- Veterinary Pathology, University of Nairobi, Nairobi, P.O. Box 30197-00100, Kenya
| | - Purity Gitonga
- Biochemistry, Kenya Agricultural and Livestock Research Organization, Nairobi, P.O. Box 362 -00902, Kenya
| | - Samuel Guya
- Biochemistry, Kenya Agricultural and Livestock Research Organization, Nairobi, P.O. Box 362 -00902, Kenya
| | - Raymond Mdachi
- Biochemistry, Kenya Agricultural and Livestock Research Organization, Nairobi, P.O. Box 362 -00902, Kenya
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Mewamba EM, Magang EMK, Tiofack AAZ, Woguia GF, Bouaka CUT, Kamga RMN, Farikou O, Fogue PS, Tume C, Ravel S, Simo G. Trypanosome infections in animals from tsetse infected areas of Cameroon and their sensitivity and resistance molecular profiles for diminazene aceturate and isometamidium chloride. Vet Parasitol Reg Stud Reports 2023; 41:100868. [PMID: 37208078 DOI: 10.1016/j.vprsr.2023.100868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 03/28/2023] [Accepted: 04/03/2023] [Indexed: 05/21/2023]
Abstract
Monitoring and assessment of control strategies for African trypanosomoses' elimination require not only updating data on trypanosome infections, but also to have an overview on the molecular profiles of trypanocides resistance in different epidemiological settings. This study was designed to determine, in animals from six tsetse-infested areas of Cameroon, the prevalence of trypanosome infections as well as the diminazene aceturate (DA) and isometamidium chloride (ISM) sensitivity/resistance molecular profiles of these trypanosomes. From 2016 to 2019, blood was collected in pigs, dogs, sheep, goats and cattle from six tsetse infested areas of Cameroon. DNA was extracted from blood and trypanosome species were identified by PCR. The sensitivity/resistance molecular profiles of trypanosomes to DA and ISM were investigated using PCR-RFLP. From 1343 blood samples collected, Trypanosoma vivax, Trypanosoma congolense forest and savannah, Trypanosoma theileri and trypanosomes of the sub-genus Trypanozoon were identified. The overall prevalence of trypanosome infections was 18.7%. These prevalence vary between trypanosome species, animal taxa, within and between sampling sites. Trypanosoma theileri was the predominant species with an infection rate of 12.1%. Trypanosomes showing resistant molecular profiles for ISM and DA were identified in animals from Tibati (2.7% for ISM and 65.6% for DA) and Kontcha (0.3% for ISM and 6.2% for DA). No trypanosome carrying resistant molecular profile for any of the two trypanocides was detected in animals from Fontem, Campo, Bipindi and Touboro. Mixed molecular profiles of sensitive/resistant trypanosomes were detected in animals from Tibati and Kontcha. Results of this study highlighted the presence of various trypanosome species as well as parasites carrying sensitive/resistant molecular profiles for DA and ISM in animals of tsetse infested areas of Cameroon. They indicate that the control strategies must be adapted according to epidemiological settings. The diversity of trypanosomes indicates that AAT remains a serious threat for animal breeding and animal health in these tsetse infested areas.
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Affiliation(s)
- Estelle Mezajou Mewamba
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
| | - Eugenie Melaine Kemta Magang
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
| | - Arnol Auvaker Zebaze Tiofack
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
| | - Gilles-Fils Woguia
- Department of Public Health, Faculty of Medicine and Biomedical Sciences, University of Yaoundé 1, Yaoundé, Cameroon
| | - Calmes Ursain Tsakeng Bouaka
- Department of Biochemistry, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon; Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
| | - Rolin Mitterran Ndeffo Kamga
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
| | - Oumarou Farikou
- Special Mission for Eradication of Tsetse flies, Regional tsetse Division of Adamawa, MINEPIA, Ngaoundere, Cameroon; Department of Biological Sciences, Faculty of Science, University of Bamenda, Bamenda, Cameroon
| | - Pythagore Sobgwi Fogue
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
| | - Christopher Tume
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon; Department of Biochemistry, Faculty of Science, University of Bamenda, Bamenda, Cameroon
| | - Sophie Ravel
- IRD INTERTRYP, CIRAD, University of Montpellier, Montpellier, France
| | - Gustave Simo
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon.
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Obi CF, Okpala MI, Anyogu DC, Onyeabor A, Ezeh IO, Ezeokonkwo RC. Comparative pathogenicity of drug-resistant and drug-sensitive Trypanosoma brucei and Trypanosoma congolense infections in Nigerian local dogs. Parasitol Res 2023; 122:49-60. [PMID: 36251088 DOI: 10.1007/s00436-022-07688-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 10/04/2022] [Indexed: 01/12/2023]
Abstract
Animal trypanosomosis is an important endemic and wasting disease in sub-Saharan Africa. Its control relies on chemotherapy, and resistance to trypanocides has been widely reported. The pathogenicity of drug-resistant canine trypanosomes is not clear with scanty information available. Thus, this study assessed the comparative pathogenicity of drug-resistant and drug-sensitive Trypanosoma brucei and Trypanosoma congolense infections in dogs. Twenty Nigerian local dogs were used and were randomly assigned into five groups (A-E) of four dogs each. Group A served as the uninfected-control group, while groups B and C were infected with 106 drug-sensitive T. congolense and T. brucei. Groups D and E were infected with 106 multidrug-resistant T. congolense and T. brucei, respectively. The pre-patent period (PPP), clinical signs, level of parasitaemia (LOP), rectal temperature, body weight, packed cell volume (PCV), red blood cell count (RBC), haemoglobin concentration (HbC), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), total leucocyte count (TLC) and survivability were assessed. Groups D and E had longer (p < 0.05) mean PPP than groups B and C. Also, group E dogs had lower (p < 0.05) mean LOP, longer (p < 0.05) mean survivability, and higher (p < 0.05) mean body weight, PCV, HbC and RBC than group C dogs. The clinical signs were very severe in group C dogs, compared to group E dogs. However, these parameters did not differ statistically between groups B and D. Thus, multidrug-resistant T. brucei was of lower pathogenicity than drug-sensitive T. brucei, while multidrug-resistant and drug-sensitive T. congolense had comparable pathogenicity following infection in dogs.
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Affiliation(s)
- Chukwunonso F Obi
- Department of Veterinary Parasitology and Entomology, Faculty of Veterinary Medicine, University of Nigeria, Nsukka, Enugu State, Nigeria.
| | - Michael I Okpala
- Department of Veterinary Parasitology and Entomology, Faculty of Veterinary Medicine, University of Nigeria, Nsukka, Enugu State, Nigeria
| | - Davinson C Anyogu
- Department of Veterinary Pathology and Microbiology, Faculty of Veterinary Medicine, University of Nigeria, Nsukka, Enugu State, Nigeria
| | - Amaechi Onyeabor
- Department of Veterinary Parasitology and Entomology, College of Veterinary Medicine, Michael Okpara University of Agriculture, Umudike, Abia State, Nigeria
| | - Ikenna O Ezeh
- Department of Veterinary Parasitology and Entomology, Faculty of Veterinary Medicine, University of Nigeria, Nsukka, Enugu State, Nigeria
| | - Romanus C Ezeokonkwo
- Department of Veterinary Parasitology and Entomology, Faculty of Veterinary Medicine, University of Nigeria, Nsukka, Enugu State, Nigeria
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Nakamura Y, Hayashida K, Delesalle V, Qiu Y, Omori R, Simuunza M, Sugimoto C, Namangala B, Yamagishi J. Genetic Diversity of African Trypanosomes in Tsetse Flies and Cattle From the Kafue Ecosystem. Front Vet Sci 2021; 8:599815. [PMID: 33585616 PMCID: PMC7873289 DOI: 10.3389/fvets.2021.599815] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 01/04/2021] [Indexed: 01/15/2023] Open
Abstract
We clarified the genetic diversity of Trypanosoma spp. within the Kafue ecosystem, using PCR targeting the internal transcribed spacer 1 and the cathepsin L-like cysteine protease (CatL) sequences. The overall prevalence of Trypanosoma spp. in cattle and tsetse flies was 12.65 and 26.85%, respectively. Cattle positive for Trypanosoma vivax had a significantly lower packed cell volume, suggesting that T. vivax is the dominant Trypanosoma spp. causing anemia in this area. Among the 12 operational taxonomic units (OTUs) of T. vivax CatL sequences detected, one was from a known T. vivax lineage, two OTUs were from known T. vivax-like lineages, and nine OTUs were considered novel T. vivax-like lineages. These findings support previous reports that indicated the extensive diversity of T. vivax-like lineages. The findings also indicate that combining CatL PCR with next generation sequencing is useful in assessing Trypanosoma spp. diversity, especially for T. vivax and T. vivax-like lineages. In addition, the 5.42% prevalence of Trypanosoma brucei rhodesiense found in cattle raises concern in the community and requires careful monitoring of human African trypanosomiasis.
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Affiliation(s)
- Yukiko Nakamura
- Graduate School of Infectious Diseases, Hokkaido University, Sapporo, Japan.,Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Kyoko Hayashida
- Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan.,International Collaboration Unit, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Victoire Delesalle
- Melindika, Non-governmental Organization of International Solidarity, Itezhi-Tezhi, Zambia
| | - Yongjin Qiu
- Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Ryosuke Omori
- Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Martin Simuunza
- Department of Disease Control, School of Veterinary Medicine, The University of Zambia, Lusaka, Zambia
| | - Chihiro Sugimoto
- Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Boniface Namangala
- Department of Para-Clinical Studies, School of Veterinary Medicine, The University of Zambia, Lusaka, Zambia
| | - Junya Yamagishi
- Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan.,International Collaboration Unit, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan
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Ndung’u K, Murilla GA, Thuita JK, Ngae GN, Auma JE, Gitonga PK, Thungu DK, Kurgat RK, Chemuliti JK, Mdachi RE. Differential virulence of Trypanosoma brucei rhodesiense isolates does not influence the outcome of treatment with anti-trypanosomal drugs in the mouse model. PLoS One 2020; 15:e0229060. [PMID: 33151938 PMCID: PMC7643984 DOI: 10.1371/journal.pone.0229060] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 07/04/2020] [Indexed: 11/19/2022] Open
Abstract
We assessed the virulence and anti-trypanosomal drug sensitivity patterns of Trypanosoma brucei rhodesiense (Tbr) isolates in the Kenya Agricultural and Livestock Research Organization-Biotechnology Research Institute (KALRO-BioRI) cryobank. Specifically, the study focused on Tbr clones originally isolated from the western Kenya/eastern Uganda focus of human African Trypanosomiasis (HAT). Twelve (12) Tbr clones were assessed for virulence using groups(n = 10) of Swiss White Mice monitored for 60 days post infection (dpi). Based on survival time, four classes of virulence were identified: (a) very-acute: 0-15, (b) acute: 16-30, (c) sub-acute: 31-45 and (d) chronic: 46-60 dpi. Other virulence biomarkers identified included: pre-patent period (pp), parasitaemia progression, packed cell volume (PCV) and body weight changes. The test Tbr clones together with KALRO-BioRi reference drug-resistant and drug sensitive isolates were then tested for sensitivity to melarsoprol (mel B), pentamidine, diminazene aceturate and suramin, using mice groups (n = 5) treated with single doses of each drug at 24 hours post infection. Our results showed that the clones were distributed among four classes of virulence as follows: 3/12 (very-acute), 3/12 (acute), 2/12 (sub-acute) and 4/12 (chronic) isolates. Differences in survivorship, parasitaemia progression and PCV were significant (P<0.001) and correlated. The isolate considered to be drug resistant at KALRO-BioRI, KETRI 2538, was confirmed to be resistant to melarsoprol, pentamidine and diminazene aceturate but it was not resistant to suramin. A cure rate of at least 80% was achieved for all test isolates with melarsoprol (1mg/Kg and 20 mg/kg), pentamidine (5 and 20 mg/kg), diminazene aceturate (5 mg/kg) and suramin (5 mg/kg) indicating that the isolates were not resistant to any of the drugs despite the differences in virulence. This study provides evidence of variations in virulence of Tbr clones from a single HAT focus and confirms that this variations is not a significant determinant of isolate sensitivity to anti-trypanosomal drugs.
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Affiliation(s)
- Kariuki Ndung’u
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Kikuyu, Kenya
- * E-mail:
| | - Grace Adira Murilla
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Kikuyu, Kenya
- KAG EAST University, Nairobi, Kenya
| | - John Kibuthu Thuita
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Kikuyu, Kenya
- Meru University of Science and Technology, Meru, Kenya
| | - Geoffrey Njuguna Ngae
- Food Crops Research Institute, Kenya Agricultural and Livestock Research Organization, Nairobi, Kenya
| | - Joanna Eseri Auma
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Kikuyu, Kenya
| | - Purity Kaari Gitonga
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Kikuyu, Kenya
| | - Daniel Kahiga Thungu
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Kikuyu, Kenya
| | - Richard Kiptum Kurgat
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Kikuyu, Kenya
| | - Judith Kusimba Chemuliti
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Kikuyu, Kenya
| | - Raymond Ellie Mdachi
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Kikuyu, Kenya
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Mewamba EM, Farikou O, Kamga RMN, Magang MEK, Tume C, Tiofack AAZ, Ravel S, Simo G. Molecular identification of diminazene aceturate-resistant strains of Trypanosoma congolense in naturally infected domestic animals of Yoko in the centre region of Cameroon. VETERINARY PARASITOLOGY- REGIONAL STUDIES AND REPORTS 2020; 20:100405. [PMID: 32448545 DOI: 10.1016/j.vprsr.2020.100405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Revised: 03/20/2020] [Accepted: 03/24/2020] [Indexed: 11/15/2022]
Abstract
African animal trypanosomiases (AAT) remain the major constraint for livestock production, agriculture and food security in Africa. Although several control measures have been developed to fight AAT, the use of trypanocides remains the main strategy in most affected poor and rural communities. However, several studies have highlighted drug-resistant-trypanosome infections in many African countries, though this phenomenon is still not well described. This study aims to detect trypanosome species and the molecular profiles of drug-resistant-trypanosomes in naturally infected domestic animals of Yoko in the centre region of southern Cameroon. Therefore, in October 2017, 348 animals were blood sampled. The level of packed cell volume (PCV) was evaluated in each animal and trypanosome infections were investigated with the capillary tube centrifugation technique (CTC). Thereafter, DNA was extracted from blood samples and different trypanosome species were identified by PCR. The resistant/sensitive molecular profiles of trypanosomes for diminazene aceturate (DA) and isometamidium chloride (ISM) were investigated by PCR-RFLP. About 18.4% (64/348) of animals analyzed by PCR were found with trypanosome infections including Trypanosoma vivax, Trypanosoma brucei s.l. and Trypanosoma congolense forest and savannah. Trypanosoma congolense savannah was the predominant species with an infection rate of 15.2%. Between villages, significant (p˂0.0001) differences were found in the overall trypanosome infection rates. No molecular profile for ISM resistant-trypanosomes was identified. Conversely, about 88.9% (40/45) of T. congolense positive samples have shown molecular profiles of DA-resistant strains while the remaining 11.1% (5/45) showed mixed molecular profiles of resistant/sensitive strains. Results showed that the molecular profiles of DA-resistant strains of T. congolense in domestic animals of Yoko were widespread. This data needs to be confirmed by testing in vivo the drug susceptibilities of the trypanosome strains herein detected. In conclusion, appropriate future control measures are required. In addition to the intensification of vector control, ISM is advised for the treatment of animals infected by trypanosomes.
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Affiliation(s)
- Estelle Mezajou Mewamba
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, PO. Box 67, Dschang, Cameroon
| | | | - Rolin Mitterran Ndefo Kamga
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, PO. Box 67, Dschang, Cameroon
| | - Melaine Eugenie Kemta Magang
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, PO. Box 67, Dschang, Cameroon
| | | | - Arnol Auvaker Zébazé Tiofack
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, PO. Box 67, Dschang, Cameroon
| | - Sophie Ravel
- Institut de Recherche pour le Développement, UMR INTERTRYP, Montpellier, France
| | - Gustave Simo
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, PO. Box 67, Dschang, Cameroon.
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Latif AA, Ntantiso L, De Beer C. African animal trypanosomosis (nagana) in northern KwaZulu-Natal, South Africa: Strategic treatment of cattle on a farm in endemic area. ACTA ACUST UNITED AC 2019; 86:e1-e6. [PMID: 31170783 PMCID: PMC6556924 DOI: 10.4102/ojvr.v86i1.1639] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 01/02/2019] [Accepted: 01/09/2019] [Indexed: 11/04/2022]
Abstract
African animal trypanosomosis (AAT) is caused by several species of the genus Trypanosoma, a parasitic protozoan infecting domestic and wild animals. One of the major effects of infection with pathogenic trypanosome is anaemia. Currently, the control policies for tsetse and trypanosomosis are less effective in South Africa. The only response was to block treat all infected herds and change the dip chemical to one which controls tsetse flies during severe outbreaks. This policy proved to be less effective as demonstrated by the current high level of trypanosome infections in cattle. Our objective was to study the impacts of AAT (nagana) on animal productivity by monitoring the health of cattle herds kept in tsetse and trypanosomosis endemic areas before and after an intervention that reduces the incidence of the disease. The study was conducted on a farm in northern KwaZulu-Natal which kept a commercial cattle herd. There was no history of any cattle treatment for trypanosome. All cattle were generally in poor health condition at the start of the study though the herd received regular anthelminthic treatment. A treatment strategy using two drugs, homidium bromide (ethidium) and homidium chloride (novidium), was implemented. Cattle were monitored regularly for 13 months for herd trypanosomosis prevalence (HP), herd average packed cell volume (H-PCV) and the percentage of the herd that was anaemic (HA). A total of six odour-baited H-traps were deployed where cattle grazed from January 2006 to August 2007 to monitor the tsetse population. Glossina brevipalpis Newstead and Glossina austeni Newstead were collected continuously for the entire study period. High trypanosomes HP (44%), low average H-PCV (29.5) and HA (24%) were rerecorded in the baseline survey. All cattle in the herd received their first treatment with ethidium bromide. Regular monthly sampling of cattle for the next 142 days showed a decline in HP of 2.2% – 2.8%. However, an HP of 20% was recorded by day 220 and the herd received the second treatment using novidium chloride. The HP dropped to 0.0% and HA to 0.0% by day 116 after the second treatment. The cow group was treated again by day 160 when the HP and HA were 27.3% and 11%, respectively. The same strategy was applied to the other two groups of weaners and the calves at the time when their HP reached 20%. Ethidium and novidium treatment protected cattle, that were under continuous tsetse and trypanosomosis challenge, for up to 6 months. Two to three treatments per year may be sufficient for extended protection. However, this strategy would need to be included into an integrated pest management approach combining vector control for it to be sustainable.
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Affiliation(s)
- Abdalla A Latif
- School of Life Sciences, University of KwaZulu-Natal, Westville, Durban.
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Ramirez-Barrios R, Reyna-Bello A, Parra O, Valeris R, Tavares-Marques L, Brizard JP, Demettre E, Seveno M, Martinez-Moreno A, Holzmuller P. Trypanosoma vivax infection in sheep: Different patterns of virulence and pathogenicity associated with differentially expressed proteomes. Vet Parasitol 2019; 276S:100014. [PMID: 32904712 PMCID: PMC7458391 DOI: 10.1016/j.vpoa.2019.100014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 05/22/2019] [Accepted: 05/27/2019] [Indexed: 11/18/2022]
Abstract
Trypanosoma vivax strains exhibit different virulence and pathogenicity patterns. TvMT1 strain showed low virulence and high pathogenicity. TvLIEM176 strain showed high virulence and moderate pathogenicity. Protein expression varies in high virulence/moderate pathogenicity strain vs low virulence/high pathogenicity strain.
Cattle trypanosomosis caused by Trypanosoma vivax is a widely distributed disease in Africa and Latin America. It causes significant losses in the livestock industry and is characterized by fluctuating parasitemia, anemia, fever, lethargy, and weight loss. In this study we evaluated the virulence (capacity to multiply inside the host and to modulate the host response) and pathogenicity (ability to produce disease and/or mortality) patterns of two T. vivax strains (TvMT1 and TvLIEM176) in experimentally-infected sheep and determined the proteins differentially expressed in the proteomes of these two strains. Hematological and clinical parameters were monitored in experimentally-infected versus non-infected sheep for 60 days. All the infected animals developed discernable parasitemia at 3 days post-infection (dpi), and the first parasitemia peak was observed at 6 dpi. The maximum average value of parasitemia was 1.3 × 107 (95% CI, 7.9 × 105–2 × 108) parasites/ml in TvLIEM176-infected animals, and 2.5 × 106 (95% CI, 1.6 × 105–4 × 107) parasites/ml in TvMT1-infected ones. Anemia and clinical manifestations were more severe in the animals infected by TvMT1 strain than in those infected by TvLIEM176. In the proteomic analysis, a total of 29 proteins were identified, of which 14 exhibited significant differences in their expression levels between strains. Proteins with higher expression in TvLIEM176 were: alpha tubulin, beta tubulin, arginine kinase, glucose-regulated protein 78, paraflagellar protein 3, and T-complex protein 1 subunit theta. Proteins with higher expression in TvMT1 were: chaperonin HSP60, T-complex protein 1 subunit alpha, heat shock protein 70, pyruvate kinase, glycerol kinase, inosine-5'-monophosphate dehydrogenase, 73 kDa paraflagellar rod protein, and vacuolar ATP synthase. There was a difference in the virulence and pathogenicity between the T. vivax strains: TvLIEM176 showed high virulence and moderate pathogenicity, whereas TvMT1 showed low virulence and high pathogenicity. The proteins identified in this study are discussed for their potential involvement in strains’ virulence and pathogenicity, to be further defined as biomarkers of severity in T. vivax infections.
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Perrone T, Sánchez E, Hidalgo L, Mijares A, Balzano-Nogueira L, Gonzatti MI, Aso PM. Infectivity and virulence of Trypanosoma evansi and Trypanosoma equiperdum Venezuelan strains from three different host species. VETERINARY PARASITOLOGY- REGIONAL STUDIES AND REPORTS 2018; 13:205-211. [PMID: 31014875 DOI: 10.1016/j.vprsr.2018.07.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Revised: 05/30/2018] [Accepted: 07/06/2018] [Indexed: 10/28/2022]
Abstract
The infectivity and virulence of seven Trypanosoma evansi and Trypanosoma equiperdum Venezuelan strains isolated from horses, donkeys and capybaras were compared in a mouse model up to 41 days, for parasitemia, animal weight, survival rates, packed cell volume, haemoglobin and erythrocyte count. Two T. equiperdum strains and three of the T. evansi strains resulted in 100% mice mortality, while the two T. evansi donkey strains exhibited lower infectivity and mortality. T. equiperdum strains had shorter pre-patent periods (4 days) than the T. evansi strains (4-12 days). In terms of pathogenicity, only the T. evansi horse strain and the two capybara strains produced a significant decrease of the packed cell volume, in haemoglobin concentration and in red blood cell count. In contrast, the T. evansi donkey strains did not show any changes in the hematological parameters. From the seven variables studied, only pre-patent period, day of maximum parasitemia, day of first parasitemia peak and number of parasitemia peaks were statistically significant. Weight decrease was only observed in mice infected with the T. evansi horse strain. T. equiperdum strains showed the highest mice lethality (7% survival by day 8 post-infection) with no change in the hematological parameters. The three T. evansi horse and capybara strains showed 80%, 87% and 97% survival rates, respectively by day 12 post-infection. However, by day 20 post-inoculation all the mice infected with the T. evansi horse strain died, while 53% and 27% capybara strains infected survived. Whereas by day 40 post-infection, 53 and 73% of the mice infected with the T. evansi donkey strains had survived. These results demonstrate striking infectivity and virulence differences between Venezuelan T. evansi and T. equiperdum strains in NMRI mice and open new possibilities to characterize inter and intra-species variations that may contribute to the pathogenicity of these two species.
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Affiliation(s)
- Trina Perrone
- Grupo de Bioquímica e Inmunología de Hemoparásitos, Departamento de Biología Celular, Universidad Simón Bolívar, Caracas 1080, Venezuela; Laboratorio de Fisiología de Parásitos, Centro de Biofísica y Bioquímica, Instituto Venezolano de Investigaciones Científicas, Altos de Pipe 1020A, Venezuela
| | - Evangelina Sánchez
- Laboratorio de Fisiología de Parásitos, Centro de Biofísica y Bioquímica, Instituto Venezolano de Investigaciones Científicas, Altos de Pipe 1020A, Venezuela.
| | - Luis Hidalgo
- Bioterio, Universidad Simón Bolívar, Caracas 1080, Venezuela
| | - Alfredo Mijares
- Laboratorio de Fisiología de Parásitos, Centro de Biofísica y Bioquímica, Instituto Venezolano de Investigaciones Científicas, Altos de Pipe 1020A, Venezuela
| | - Leandro Balzano-Nogueira
- Microbiology and Cell Science Department, Institute for Food and Agricultural Sciences, University of Florida, Gainesville, USA
| | - Mary Isabel Gonzatti
- Grupo de Bioquímica e Inmunología de Hemoparásitos, Departamento de Biología Celular, Universidad Simón Bolívar, Caracas 1080, Venezuela.
| | - Pedro María Aso
- Grupo de Bioquímica e Inmunología de Hemoparásitos, Departamento de Biología Celular, Universidad Simón Bolívar, Caracas 1080, Venezuela.
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T P, P M A, A M, P H, M G, N P. Comparison of infectivity and virulence of clones of Trypanosoma evansi and Ttrypanosoma equiperdum Venezuelan strains in mice. Vet Parasitol 2018; 253:60-64. [PMID: 29605005 DOI: 10.1016/j.vetpar.2018.02.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 02/06/2018] [Accepted: 02/10/2018] [Indexed: 10/18/2022]
Abstract
Livestock trypanosomoses, caused by three species of the Trypanozoon subgenus, Trypanosoma brucei brucei, T. evansi and T. equiperdum are widely distributed and limit animal production throughout the world. The infectivity and virulence of clones derived from Trypanosoma evansi and Trypanosoma equiperdum Venezuelan strains were compared in an in vivo mouse model. Primary infectivity and virulence determinants such as survival rates, parasitemia levels, PCV, and changes in body weight and survival rates were monitored for up to 32 days. The T. equiperdum strain was the most virulent, with 100% mortality in mice, with the highest parasitemia levels (7.0 × 107 Tryps/ml) and loss of physical condition. The T. evansi strains induced 100% and 20% fatality in mice. Our results show that the homogeneous parasite populations maintain the virulent phenotype of the original T. equiperdum and T. evansi stocks. This is the first comparative study of infectivity and virulence determinants among clonal populations of T. equiperdum and T. evansi.
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Affiliation(s)
- Perrone T
- Laboratorio de Fisiología de Parásitos, Centro de Biofísica y Bioquímica, Instituto Venezolano de Investigaciones Científicas, Altos de Pipe, 1020A, Venezuela; Grupo de Bioquímica e Inmunología de Hemoparásitos, Departamento de Biología Celular, Universidad Simón Bolívar, Caracas 1080, Venezuela
| | - Aso P M
- Grupo de Bioquímica e Inmunología de Hemoparásitos, Departamento de Biología Celular, Universidad Simón Bolívar, Caracas 1080, Venezuela
| | - Mijares A
- Laboratorio de Fisiología de Parásitos, Centro de Biofísica y Bioquímica, Instituto Venezolano de Investigaciones Científicas, Altos de Pipe, 1020A, Venezuela
| | - Holzmuller P
- CIRAD, UMR CIRAD-INRA CMAEE, UMR CIRAD-IRD INTERTRYP, Montpellier, France
| | - Gonzatti M
- Grupo de Bioquímica e Inmunología de Hemoparásitos, Departamento de Biología Celular, Universidad Simón Bolívar, Caracas 1080, Venezuela
| | - Parra N
- Laboratorio de Fisiología de Parásitos, Centro de Biofísica y Bioquímica, Instituto Venezolano de Investigaciones Científicas, Altos de Pipe, 1020A, Venezuela.
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Kassian EN, Simuunza MC, Silayo RS, Moonga L, Ndebe J, Sugimoto C, Namangala B. Prevalence and risk factors of bovine trypanosomosis in Kilwa district, Lindi region of southern Tanzania. VETERINARY PARASITOLOGY- REGIONAL STUDIES AND REPORTS 2017; 9:1-5. [PMID: 31014830 DOI: 10.1016/j.vprsr.2017.03.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 03/12/2017] [Accepted: 03/12/2017] [Indexed: 11/16/2022]
Abstract
African animal trypanosomosis (AAT) and human African trypanosomosis (HAT) are complex chronic, debilitating, emaciating and often fatal diseases of animals and humans, respectively. This cross-sectional study was conducted to determine the prevalence and risk factors associated with bovine trypanosomosis in tsetse-infested Kilwa district, Lindi region, southern Tanzania. Blood samples were collected from 420 cattle randomly selected from 86 herds from ten villages. A maximum of ten herds per village and at most six animals from each herd were selected for sampling. At the same time, a questionnaire was administered. Individual animal samples were analysed using microscopy and pooled sample at herd level were analysed by loop mediated isothermal amplification (LAMP). A herd was considered positive if at least one animal in the herd was positive for AAT. A prevalence of 9.3% (95% CI: 2.9-14.9) was recorded for AAT by microscopy, mainly caused by Trypanosoma congolense (5.8%, 95% CI=0.9-10.7), Trypanosoma brucei species (5.8%, 95%, CI=0.9-10.7) and Trypanosoma vivax (3.5%, 95% CI=0-7.4). Loop mediated isothermal amplification (LAMP) recorded a heard prevalence of 41.9% (95% CI: 30.0-51.4%), mainly caused by T. congolense (30.2%, 95% CI: 20.5-39.9), T. brucei species (25.6%, 95% CI: 16.4-34.8) and T. vivax (20.9%, 95% CI: 12.3-29.7). Most of the cattle herds had mixed infections of these parasites. According to LAMP, Miteja and Matandu villages had the highest AAT herd prevalence of 57% (95% CI: 20.3-93.7) while Mavuji had the lowest prevalence of 14% (95% CI: 0-39.7). Data from the present study suggest that district of origin, grazing in game reserve, water source and form of watering point are risk factors associated with AAT in Kilwa district, southern Tanzania. Continuous surveillance and monitoring of AAT using more sensitive are recommended.
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Affiliation(s)
- E N Kassian
- Department of Livestock and Fisheries Development, Kilwa District Council, P.O. Box 160, Kilwa, Tanzania
| | - M C Simuunza
- Department of Disease Control, School of Veterinary Medicine, University of Zambia, P.O. Box 32379, Lusaka, Zambia
| | - R S Silayo
- Department of Microbiology and Parasitology, Faculty of Veterinary Medicine, Sokoine University of Agriculture, P.O. Box 3012, Morogoro, Tanzania
| | - L Moonga
- Department of Paraclinical Studies, School of Veterinary Medicine, University of Zambia, P.O. Box 32379, Lusaka, Zambia
| | - J Ndebe
- Department of Disease Control, School of Veterinary Medicine, University of Zambia, P.O. Box 32379, Lusaka, Zambia
| | - C Sugimoto
- Research Centre for Zoonosis Control, Hokkaido University, Kita-Ku, Sapporo 001-0020, Japan
| | - B Namangala
- Department of Paraclinical Studies, School of Veterinary Medicine, University of Zambia, P.O. Box 32379, Lusaka, Zambia.
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MUSINGUZI SP, SUGANUMA K, ASADA M, LAOHASINNARONG D, SIVAKUMAR T, YOKOYAMA N, NAMANGALA B, SUGIMOTO C, SUZUKI Y, XUAN X, INOUE N. A PCR-based survey of animal African trypanosomosis and selected piroplasm parasites of cattle and goats in Zambia. J Vet Med Sci 2017; 78:1819-1824. [PMID: 27616437 PMCID: PMC5240760 DOI: 10.1292/jvms.16-0240] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 08/27/2016] [Indexed: 11/22/2022] Open
Abstract
We screened cattle and goats from the districts of Chama, Monze and Mumbwa in Zambia for animal African trypanosomes, Babesia bigemina and Theileria parva using PCRs; 38.1% of the samples tested positive for at least one of the parasite species. The most common parasite was Trypanosoma vivax (19.8%). Its incidence was significantly higher in goats than in cattle, (P<0.05). B. bigemina was found in samples from all the three areas, making it the most widespread of the parasites in Zambia. Among the tested samples, 12.0% of the positive samples were mixed infections. There were significant differences in the infection rates of T. vivax (Mumbwa had a significantly higher infection rate [39.6%, P<0.0001]), Th. parva (Monze had the only cases [P<0.0004]) and B. bigemina (Monze had a significantly higher infection rate [40.5%, P<0.0001]). According to the hematocrit values, the packed cell volume (%) among the cattle with mixed infections was significantly lower than that of the other cattle. The presence of multiple parasite species and mixed infections among the Zambian cattle and goat populations is of both clinical and economic importance to livestock farming. The absence of trypanosomosis among the samples from Monze can be attributed to tsetse eradication efforts that took place around Lake Kariba. This shows that the prevention and control of these parasitic diseases can have a significant impact on the disease status, which can translate directly into the improvement of the livestock sector in Zambia.
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Affiliation(s)
- Simon Peter MUSINGUZI
- OIE Reference Laboratory on Surra, National Research Center
for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine,
Inada-cho, Obihiro, Hokkaido 080–8555, Japan
| | - Keisuke SUGANUMA
- OIE Reference Laboratory on Surra, National Research Center
for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine,
Inada-cho, Obihiro, Hokkaido 080–8555, Japan
| | - Masahito ASADA
- Department of Protozoology, Institute of Tropical Medicine
(NEKKEN), Nagasaki University, 1–12–4 Sakamoto, Nagasaki 852–8523, Japan
| | - Dusit LAOHASINNARONG
- Faculty of Veterinary Science, Mahidol University, 999
Phuttamonthon Sai 4, Salaya, Phuttamonthon, Nakhon Pathom 73170, Thailand
| | - Thillaiampalam SIVAKUMAR
- OIE Reference Laboratory on Surra, National Research Center
for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine,
Inada-cho, Obihiro, Hokkaido 080–8555, Japan
- Veterinary Research Institute, Peradeniya, Sri Lanka
| | - Naoaki YOKOYAMA
- OIE Reference Laboratory on Surra, National Research Center
for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine,
Inada-cho, Obihiro, Hokkaido 080–8555, Japan
| | - Boniface NAMANGALA
- Department of Paraclinical Studies, School of Veterinary
Medicine, University of Zambia, P.O. Box 32379, Lusaka, Zambia
| | - Chihiro SUGIMOTO
- Research Center for Zoonosis Control, Hokkaido University,
Sapporo, Hokkaido 060–0818, Japan
| | - Yasuhiko SUZUKI
- Research Center for Zoonosis Control, Hokkaido University,
Sapporo, Hokkaido 060–0818, Japan
| | - Xuenan XUAN
- OIE Reference Laboratory on Surra, National Research Center
for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine,
Inada-cho, Obihiro, Hokkaido 080–8555, Japan
| | - Noboru INOUE
- OIE Reference Laboratory on Surra, National Research Center
for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine,
Inada-cho, Obihiro, Hokkaido 080–8555, Japan
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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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Motloang MY, Masumu J, Mans BJ, Latif AA. Virulence of Trypanosoma congolense strains isolated from cattle and African buffaloes (Syncerus caffer) in KwaZulu-Natal, South Africa. ACTA ACUST UNITED AC 2014; 81:e1-e7. [PMID: 25685920 DOI: 10.4102/ojvr.v81i1.679] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Revised: 06/03/2014] [Accepted: 06/03/2014] [Indexed: 11/01/2022]
Abstract
Trypanosoma congolense and Trypanosoma vivax are major species that infect cattle in north-eastern KwaZulu-Natal (KZN), South Africa. Of the two genetically distinct types of T. congolense, Savannah and Kilifi sub-groups, isolated from cattle and tsetse flies in KZN, the former is more prevalent and thought to be responsible for African animal trypanosomosis outbreaks in cattle. Furthermore, variation in pathogenicity within the Savannah sub-group is ascribed to strain differences and seems to be related to geographical locations. The objective of the present study was to compare the virulence of T. congolense strains isolated from African buffaloes (Syncerus caffer) inside Hluhluwe-iMfolozi Park, and from cattle on farms near wildlife parks (< 5 km), to isolates from cattle kept away (> 10 km) from parks. To obtain T. congolense isolates, blood of known parasitologically positive cattle or cattle symptomatically suspect with trypanosomosis, as well as isolates from buffaloes kept inside Hluhluwe-iMfolozi Park were passaged in inbred BALB/c mice. A total of 26 T. congolense isolates were obtained: 5 from buffaloes, 13 from cattle kept near parks and 8 from cattle distant from parks. Molecular characterisation revealed 80% and 20% of isolates to belong to T. congolense Savannah and Kilifi, respectively. To compare virulence, each isolate was inoculated into a group of six mice. No statistical differences were observed in the mean pre-patent period, maximum parasitaemia or drop in packed cell volume (PCV). Significant differences were found in days after infection for the drop in PCV, the patent period and the survival time. These differences were used to categorise the isolates as being of high, moderate or low virulence. Based on the virulence, 12 of 26 (46%) isolates were classified as highly virulent and 27% each as either of moderate or of low virulence. Whilst 11 of 12 high virulent strains were from buffaloes or cattle near the park, only 1 of 7 low virulent strains was from these animals. All the Kilifi T. congolense types were less virulent than the Savannah types. These results confirmed the higher virulence of T. congolense Savannah type compared to Kilifi type and indicated the prevalence of highly virulent strains to be higher in wildlife parks and in cattle near the parks than on farms further away. The geographical location of these strains in relation to the wildlife parks in the area was discussed.
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Affiliation(s)
- Makhosazana Y Motloang
- Parasites, Vectors and Vector-borne Diseases Programme, Agricultural Research Council - Onderstepoort Veterinary Institute.
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Simo G, Fogue PS, Melachio TTT, Njiokou F, Kuiate JR, Asonganyi T. Population genetics of forest type of Trypanosoma congolense circulating in Glossina palpalis palpalis of Fontem in the South-West region of Cameroon. Parasit Vectors 2014; 7:385. [PMID: 25142136 PMCID: PMC4261900 DOI: 10.1186/1756-3305-7-385] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 08/08/2014] [Indexed: 11/11/2022] Open
Abstract
Background Genetic variation of microsatellite loci is a widely used method for the analysis of population genetic structure of several organisms. To improve our knowledge on the population genetics of trypanosomes, Trypanosoma congolense forest and savannah types were identified in the mid-guts of Glossina palpalis palpalis caught in five villages of Fontem in the South-West region of Cameroon. From the positive samples of Trypanosoma congolense forest, the genetic diversity and the population genetic structure of these parasites were evaluated. Method For this study, pyramidal traps were set up during three entomological surveys and 3347 tsetse flies were collected, dissected and 1903 midguts collected. DNA was extracted from midguts and specific primers were used to identify Trypanosoma congolense forest and savannah. All Trypanosoma congolense forest positive samples were characterized with seven microsatellite markers. Results Microscopic examination revealed 25 (1.31%) mid-gut infections with trypanosomes while the PCR method identified 120 (6.3%) infections due to Trypanosoma congolense: 94 (78.33%) Trypanosoma congolense forest and 28 (21.77%) Trypanosoma congolense savannah. The trypanosome infection rates varied significantly between villages and years of capture. Menji recorded the highest infection rate (15.11%); and samples captured in 2009 were more infected (14.33%). The microsatellite markers revealed a genetic variability between Trypanosoma congolense forest populations of Fontem villages and 6.38% of mixed infections due to different genotypes of T. congolense “forest type”. Conclusion Our data on the population genetics play in favor of a clonal reproduction of this parasite. The microsatellite markers used here showed a low genetic differentiation and an absence of sub-structuration (FST ≤ 0.0003) between Trypanosoma congolense forest populations of Fontem villages. However, the high FST value (FST ≥ 0.3911) between samples of the Democratic Republic of Congo and those of Fontem villages indicates low migration rates between trypanosomes of these subpopulations. Electronic supplementary material The online version of this article (doi:10.1186/1756-3305-7-385) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Gustave Simo
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, Cameroon, PO Box 67, Dschang, Cameroon.
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Rodrigues AC, Ortiz PA, Costa-Martins AG, Neves L, Garcia HA, Alves JM, Camargo EP, Alfieri SC, Gibson W, Teixeira MM. Congopain genes diverged to become specific to Savannah, Forest and Kilifi subgroups of Trypanosoma congolense, and are valuable for diagnosis, genotyping and phylogenetic inferences. INFECTION GENETICS AND EVOLUTION 2014; 23:20-31. [DOI: 10.1016/j.meegid.2014.01.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Revised: 01/10/2014] [Accepted: 01/11/2014] [Indexed: 10/25/2022]
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Whole-genome sequencing of Trypanosoma brucei reveals introgression between subspecies that is associated with virulence. mBio 2013; 4:mBio.00197-13. [PMID: 23963174 PMCID: PMC3747575 DOI: 10.1128/mbio.00197-13] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Human African trypanosomiasis is caused by two subspecies of Trypanosoma brucei. Trypanosoma brucei rhodesiense is found in East Africa and frequently causes acute disease, while Trypanosoma brucei gambiense is found in West Africa and is associated with chronic disease. Samples taken from a single focus of a Ugandan outbreak of T. b. rhodesiense in the 1980s were associated with either chronic or acute disease. We sequenced the whole genomes of two of these isolates, which showed that they are genetically distinct from each other. Analysis of single nucleotide polymorphism markers in a panel of 31 Ugandan isolates plus 32 controls revealed a mixture of East African and West African haplotypes, and some of these haplotypes were associated with the different virulence phenotypes. It has been shown recently that T. b. brucei and T. b. rhodesiense populations undergo genetic exchange in natural populations. Our analysis showed that these strains from the Ugandan epidemic were intermediate between the reference genome sequences of T. b. gambiense and T. b. brucei and contained haplotypes that were present in both subspecies. This suggests that the human-infective subspecies of T. brucei are not genetically isolated, and our data are consistent with genomic introgression between East African and West African T. b. brucei subspecies. This has implications for the control of the parasite, the spread of drug resistance, and understanding the variation in virulence and the emergence of human infectivity. IMPORTANCE We present a genetic study of the acute form of "sleeping sickness" caused by the protozoan parasite Trypanosoma brucei rhodesiense from a single outbreak in Uganda. This represents an advance in our understanding of the relationship between the T. b. rhodesiense and Trypanosoma brucei gambiense subspecies that have previously been considered geographically distinct. Our data suggest that introgression of West African-derived T. brucei haplotypes may be associated with differences in disease presentation in the East African disease. These findings are not only of scientific interest but also important for parasite control, as they suggest that the human-infective T. brucei subspecies are not genetically isolated.
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Simo G, Sobgwi PF, Njitchouang GR, Njiokou F, Kuiate JR, Cuny G, Asonganyi T. Identification and genetic characterization of Trypanosoma congolense in domestic animals of Fontem in the South-West region of Cameroon. INFECTION GENETICS AND EVOLUTION 2013; 18:66-73. [PMID: 23624186 DOI: 10.1016/j.meegid.2013.04.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Revised: 03/30/2013] [Accepted: 04/16/2013] [Indexed: 10/26/2022]
Abstract
To understand the circulation and the spread of Trypanosoma congolense genotypes in animals of Fontem in the southwest region of Cameroon, T. congolense forest and T. congolense savannah were investigated in 397 domestic animals in eight villages. Out of the 397 domestic animals, 86 (21.7%) were found infected by trypanosomes, using the capillary tube centrifugation test. The PCR with specific primers identified 163 (41.1%) and 81 (20.4%) animals infected by T. congolense forest and T. congolense savannah, respectively; showing for the first time the circulation of T. congolense savannah in the Fontem region. No infection with T. congolense savannah was found in pigs whereas goats and sheep were infected by T. congolense forest and/or T. congolense savannah. The prevalence of trypanosomes varied significantly amongst villages and animal species. The genotyping of T. congolense forest positive samples using microsatellites markers showed that multiple genotypes occurred in 27.2% (44/163) of animals sampled, whereas single genotypes were found in 73.8% (119/163) of samples. Some alleles were found in all animal species as well as in all villages and were responsible for major genotypes, whereas others (rare alleles) were identified only in some animals of few villages. These rare alleles were characteristic of specific genotypes, assimilated to minor genotypes which can be spread in the region through tsetse flies. The microsatellite markers show a low genetic variability and an absence of sub-structuration within T. congolense forest. The analysis of the microsatellite data revealed a predominant clonal reproduction within T. congolense forest. Pigs were the animal species with the highest number of different genotypes of T. congolense forest. They seem to play an important epidemiological role in the propagation and spread of different genotypes of T. congolense.
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Affiliation(s)
- Gustave Simo
- Department of Biochemistry, Faculty of Science, University of Dschang, Cameroon.
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Isolation, cloning, and pathologic analysis of Trypanosoma evansi field isolates. Parasitol Res 2013; 112:1513-21. [PMID: 23354941 PMCID: PMC3597285 DOI: 10.1007/s00436-013-3297-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Accepted: 01/11/2013] [Indexed: 11/28/2022]
Abstract
In recent years, the emergence of highly pathogenic Trypanosoma evansi strains in the Philippines has resulted in substantial losses in livestock production. In this study, we isolated T. evansi from infected-water buffaloes in the Philippines and analyzed their virulence using mice and cattle. A total of 10 strains of T. evansi were isolated. Evaluation of the virulence of each strain using mice depicted significant differences among the strains in the prepatent period, the level of parasitemia, and the survival time of the infected animals. In mice infected with the highly pathogenic T. evansi, signs of excessive inflammation such as marked splenomegaly and increase more than 6-fold in the number of leukocytes were observed at 8 days post-infection. To study the virulence of the parasite strains in cattle (which are the common T. evansi hosts in Philippines), cattle were infected with the T. evansi isolates that showed high and low virulence in mice. The rate of parasite growth and the length of the prepatent periods were found to be similar to those observed in mice for the respective strains. The cattle infected with the highly pathogenic strain developed anemia and a marked decrease in leukocyte counts. To determine the cause of the pathological changes, we analyzed the expression levels of inflammatory cytokines and observed up-regulation of tumor necrosis factor-α in anemic infected cattle. Our findings suggest that the epidemic of T. evansi in the Philippines is characterized by T. evansi strains with varying virulences from low to very high pathogenicity in cattle.
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Chitanga S, Namangala B, De Deken R, Marcotty T. Shifting from wild to domestic hosts: the effect on the transmission of Trypanosoma congolense to tsetse flies. Acta Trop 2013; 125:32-6. [PMID: 23000543 DOI: 10.1016/j.actatropica.2012.08.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Revised: 07/24/2012] [Accepted: 08/24/2012] [Indexed: 10/27/2022]
Abstract
The epidemiology and impact of animal African trypanosomosis are influenced by the transmissibility and the pathogenicity of the circulating trypanosome strains in a particular biotope. The transmissibility of 22 Trypanosoma congolense strains isolated from domestic and wild animals was evaluated in a total of 1213 flies. Multivariate mixed models were used to compare infection and maturation rates in function of trypanosome origin (domestic or sylvatic) and pathogenicity. Both trypanosome pathogenicity and origin significantly affected the ability to establish a midgut infection in tsetse flies but not the maturation rates. The interaction between pathogenicity and origin was not significant. Since being pathogenic and having a domestic origin both increased transmissibility, dominant lowly pathogenic trypanosomes from domestic environments and highly pathogenic trypanosomes from sylvatic environments presented similar levels of transmissibility: 12% and 15%, respectively. Blood meals with parasite concentration ranging from 0.05 to 50trypanosomes/μl blood for 3 strains of T. congolense were provided to different batches of tsetse flies to evaluate the relationship between the parasite load in blood meals and the likelihood for a fly to become infected. A linear relationship between parasite load and transmissibility was observed at low parasitaemia and a plateau was observed for meals containing more than 5trypanosomes/μl. Maximum transmission was reached with 12.5trypanosomes/μl blood. About 50% of the flies were refractory to T. congolense, whatever their concentration in the blood meal. The results suggest that the dose-transmissibility relationship presents a similar profile for different T. congolense isolates.
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Vitouley HS, Sidibe I, Bengaly Z, Marcotty T, Van Den Abbeele J, Delespaux V. Is trypanocidal drug resistance a threat for livestock health and production in endemic areas? Food for thoughts from Sahelian goats infected by Trypanosoma vivax in Bobo Dioulasso (Burkina Faso). Vet Parasitol 2012; 190:349-54. [DOI: 10.1016/j.vetpar.2012.07.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Revised: 07/04/2012] [Accepted: 07/10/2012] [Indexed: 11/26/2022]
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23
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Fikru R, Goddeeris BM, Delespaux V, Moti Y, Tadesse A, Bekana M, Claes F, De Deken R, Büscher P. Widespread occurrence of Trypanosoma vivax in bovines of tsetse- as well as non-tsetse-infested regions of Ethiopia: a reason for concern? Vet Parasitol 2012; 190:355-61. [PMID: 22858227 DOI: 10.1016/j.vetpar.2012.07.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Revised: 07/04/2012] [Accepted: 07/12/2012] [Indexed: 11/18/2022]
Abstract
A cross-sectional study was undertaken to assess the prevalence of bovine trypanosomosis in some tsetse-infested and tsetse-free areas of Ethiopia. From August 2010 till April 2011, a total of 1524 animals were parasitologically examined and compared by the haematocrit centrifugation technique (Woo test) and polymerase chain reaction (ITS-1 PCR). The ITS-1 PCR was more sensitive and more accurate in species identification than the Woo test. In ITS-1 PCR, an overall trypanosome prevalence of 31.0% was observed that is significantly (P<0.001) higher than in the Woo test (5.3%). Trypanosoma vivax was the predominant taxon (24.9%), followed by T. theileri (6.0%), T. congolense (2.9%) and Trypanozoon (1.6%). Mixed infections were quite common (14% of all infections). The overall prevalence of trypanosome infections in tsetse area (32.4%) was not different from non-tsetse area (30.5%) neither were the prevalences of T. vivax in both areas (respectively 22.6% and 25.7%). With these high prevalences, bovine trypanosomosis continues to hinder animal production and productivity in Ethiopia, both in tsetse-infested and non-infested parts of the country. Attempts to control African trypanosomosis should also pay attention to mechanically transmitted pathogenic trypanosomes and should adopt the most advanced molecular tests for species identification.
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Affiliation(s)
- Regassa Fikru
- College of Veterinary Medicine, Addis Ababa University, P.O. Box 34, Debre Zeit, Ethiopia
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24
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Masumu J, Tshilenge G, Mbao V. Epidemiological aspects of bovine trypanosomosis in an endemic focus of eastern Zambia: The role of trypanosome strain variability in disease pattern. ACTA ACUST UNITED AC 2012. [DOI: 10.4102/ojvr.v79i2.468] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
Bovine trypanosomosis displays various epidemiological aspects in various areas. In some instances the disease has a high prevalence in animals with high impact on production whereas in other cases the disease has a low impact on production despite a high level of infection in animals. In addition epidemiological changes are frequently observed in various areas and are related to many factors including the vectors, the host, the parasites, the environment as well as the livestock management. However the implication of these factors in these changes is not fully elucidated. In eastern Zambia, factors predicting the establishment of severe infection in cattle are all present. However trypanosomosis occurring in cattle in this area has a low impact on livestock production. Several studies on the characterisation of trypanosome strains circulating in domestic and wild animals have been conducted in order to clarify the epidemiology of this disease in this area. These studies aimed at evaluating genetic and biological characteristics of these strains including their virulence profiles, their transmissibility by tsetse flies, their resistance to drugs and interference between different strains. In this review these findings are analysed in order to elucidate the implication of trypanosome strain variability in the distribution and the expression of this disease in the study area. The evolutionary trends of the situation occurring in this study area are also explained. Use of these findings is the context of disease control in the study area is further discussed.
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Motloang M, Masumu J, Mans B, Van den Bossche P, Latif A. Vector competence of Glossina austeni and Glossina brevipalpis for Trypanosoma congolense in KwaZulu-Natal, South Africa. ACTA ACUST UNITED AC 2012; 79:E1-6. [PMID: 23327306 DOI: 10.4102/ojvr.v79i1.353] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Revised: 10/19/2011] [Accepted: 10/19/2011] [Indexed: 01/11/2023]
Abstract
Tsetse-transmitted trypanosomosis (nagana) has been the cause of stock losses in the recent past and still presents a major problem to livestock owners in certain areas of KwaZulu- Natal, South Africa. Over 10 000 cattle mortalities were reported in the 1990 nagana outbreak. Although information on the distribution and abundance of the tsetse flies Glossina brevipalpis and Glossina austeni in KwaZulu-Natal exists, data on their vector competence are lacking. This study aimed to determine the rate of natural Trypanosoma congolense infection by field-collected as well as colony-reared flies of these species. A total of 442 field-collected G. brevipalpis and 40 G. austeni flies were dissected immediately after collection to determine their infection rates, whilst 699 G. brevipalpis and 49 G. austeni flies were fed on susceptible animals in 10 and four batches, respectively, for use in xenodiagnosis experiments. Teneral colony flies were fed on infected animals and dissected 21 days post infection to confirm their infectivity testing. Glossina austeni harboured 8% immature and mature infections. In G. brevipalpis, the infection with the immature stages was lower (1%) and no mature infections were observed. Although all four batches of G. austeni transmitted T. congolense to four susceptible animals, no transmission resulted from 10 batches of G. brevipalpis fed on susceptible cattle. Colony-derived G. austeni (534) and G. brevipalpis (882) were fed on four bovines infected with different T. congolense isolates. Both G. austeni and G. brevipalpis acquired trypanosome infection from the bovines, with immature infection ranges of 20% - 33% and 1% - 4%, respectively. Parasites, however, only matured in G. austeni (average = 4%). Glossina austeni plays a larger role in the epidemiology of animal trypanosomosis in KwaZulu-Natal than G. brevipalpis and therefore more focus should be aimed at the former when control measures are implemented.
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Affiliation(s)
- Makhosazana Motloang
- Parasites, Vectors & Vector-borne Diseases Programme, ARC-Onderstepoort Veterinary Institute, Onderstepoort.
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26
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Van den Bossche P, Delespaux V. Options for the control of tsetse-transmitted livestock trypanosomosis. An epidemiological perspective. Vet Parasitol 2011; 181:37-42. [DOI: 10.1016/j.vetpar.2011.04.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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27
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VAN den BOSSCHE P, CHITANGA S, MASUMU J, MARCOTTY T, DELESPAUX V. Virulence in Trypanosoma congolense Savannah subgroup. A comparison between strains and transmission cycles. Parasite Immunol 2011; 33:456-60. [DOI: 10.1111/j.1365-3024.2010.01277.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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28
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Nimpaye H, Njiokou F, Njine T, Njitchouang G, Cuny G, Herder S, Asonganyi T, Simo G. Trypanosoma vivax, T. congolense "forest type" and T. simiae: prevalence in domestic animals of sleeping sickness foci of Cameroon. Parasite 2011; 18:171-9. [PMID: 21678793 PMCID: PMC3671417 DOI: 10.1051/parasite/2011182171] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2010] [Accepted: 10/28/2010] [Indexed: 11/26/2022] Open
Abstract
In order to better understand the epidemiology of Human and Animal trypanosomiasis that occur together in sleeping sickness foci, a study of prevalences of animal parasites (Trypanosoma vivax, T. congolense "forest type", and T. simiae) infections was conducted on domestic animals to complete the previous work carried on T. brucei gambiense prevalence using the same animal sample. 875 domestic animals, including 307 pigs, 264 goats, 267 sheep and 37 dogs were sampled in the sleeping sickness foci of Bipindi, Campo, Doumé and Fontem in Cameroon. The polymerase chain reaction (PCR) based method was used to identify these trypanosome species. A total of 237 (27.08%) domestic animals were infected by at least one trypanosome species. The prevalence of T. vivax, T. congolense "forest type" and T. simiae were 20.91%, 11.42% and 0.34% respectively. The prevalences of 7 vivax and T. congolense "forest type" differed significantly between the animal species and between the foci (p < 0.0001); however, these two trypanosomes were found in all animal species as well as in all the foci subjected to the study. The high prevalences of 7 vivax and T congolense "forest type" in Bipindi and Fontem-Center indicate their intense transmission in these foci.
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Affiliation(s)
- H. Nimpaye
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Laboratoire de Biologie Générale, Département de Biologie et Physiologie Animales, Faculté des Sciences, Université de Yaoundé I BP 812 Yaoundé Cameroun
| | - F. Njiokou
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Laboratoire de Biologie Générale, Département de Biologie et Physiologie Animales, Faculté des Sciences, Université de Yaoundé I BP 812 Yaoundé Cameroun
| | - T. Njine
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Laboratoire de Biologie Générale, Département de Biologie et Physiologie Animales, Faculté des Sciences, Université de Yaoundé I BP 812 Yaoundé Cameroun
| | - G.R. Njitchouang
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Laboratoire de Biologie Générale, Département de Biologie et Physiologie Animales, Faculté des Sciences, Université de Yaoundé I BP 812 Yaoundé Cameroun
| | - G. Cuny
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Laboratoire de Recherche et de Coordination sur les Trypanosomoses IRD, UMR 177, CIRAD, TA 207/G, Campus International de Baillarguet 34398 Montpellier Cedex 5 France
| | - S. Herder
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Laboratoire de Recherche et de Coordination sur les Trypanosomoses IRD, UMR 177, CIRAD, TA 207/G, Campus International de Baillarguet 34398 Montpellier Cedex 5 France
| | - T. Asonganyi
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Faculty of Medicine and Biomedical Sciences, University of Yaoundé I Yaoundé Cameroun
| | - G. Simo
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Department of Biochemistry, Faculty of Science, University of Dschang PO Box 67 Dschang Cameroun
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Tait A, Morrison LJ, Duffy CW, Cooper A, Turner CMR, Macleod A. Trypanosome genetics: populations, phenotypes and diversity. Vet Parasitol 2011; 181:61-8. [PMID: 21570772 DOI: 10.1016/j.vetpar.2011.04.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
In the last decade, there has been a wide range of studies using a series of molecular markers to investigate the genotypic diversity of some of the important species of African trypanosomes. Here, we review this work and provide an update of our current understanding of the mechanisms that generate this diversity based on population genetic analysis. In parallel with field based studies, our knowledge of the key features of the system of genetic exchange in Trypanosoma brucei, based on laboratory analysis, has reached the point at which this system can be used as a tool to determine the genetic basis of a phenotype. In this context, we have outlined our current knowledge of the basis for phenotypic variation among strains of trypanosomes, and highlight that this is a relatively under researched area, except for work on drug resistance. There is clear evidence for 'strain'-specific variation in tsetse transmission, a range of virulence/pathogenesis phenotypes and the ability to cross the blood brain barrier. The potential for using genetic analysis to dissect these phenotypes is illustrated by the recent work defining a locus determining organomegaly for T. brucei. When these results are considered in relation to the body of research on the variability of the host response to infection, it is clear that there is a need to integrate the study of host and parasite diversity in relation to understanding infection outcome.
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Affiliation(s)
- Andy Tait
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, United Kingdom.
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30
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A spectrum of disease in human African trypanosomiasis: the host and parasite genetics of virulence. Parasitology 2010; 137:2007-15. [PMID: 20663245 DOI: 10.1017/s0031182010000946] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
For over 50 years it has been known that there are considerable differences in the severity and rate of progression of both Trypanosoma brucei rhodesiense and T. b. gambiense infection between individuals. Yet research into the factors, whether parasite or host, which control virulence in Human African trypanosomiasis is in its infancy. In this paper we review the clinical evidence for virulence variation and the epidemiological and experimental data that give clues as to the mechanisms involved. Evidence will be presented for both asymptomatic forms of T. b. gambiense infection and low virulence forms of T. b. rhodesiense infection in humans. While in both cases the mechanisms remain to be elucidated, the overall infection virulence phenotype is determined by both parasite and host genotype.
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A changing environment and the epidemiology of tsetse-transmitted livestock trypanosomiasis. Trends Parasitol 2010; 26:236-43. [PMID: 20304707 DOI: 10.1016/j.pt.2010.02.010] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2009] [Revised: 02/11/2010] [Accepted: 02/22/2010] [Indexed: 11/30/2022]
Abstract
The distribution, prevalence and impact of vector-borne diseases are often affected by anthropogenic environmental changes that alter the interactions between the host, the parasite and the vector. In the case of tsetse-transmitted livestock trypanosomiasis these changes are a result of the encroachment of people and their livestock into tsetse-infected wild areas. This has created a sequence of new epidemiological settings that is changing the relative importance of the domestic or sylvatic trypanosome transmission cycles and is causing concomitant changes in the impact of the disease on livestock. These changes in the dynamics of the epidemiology have an important impact on the factors that need to be considered when developing area-specific strategies for the future management of tsetse-transmitted livestock trypanosomiasis.
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Masumu J, Akoda K, Van den Bossche P. Transmissibility, by Glossina morsitans morsitans, of Trypanosoma congolense strains during the acute and chronic phases of infection. Acta Trop 2010; 113:195-8. [PMID: 19765543 DOI: 10.1016/j.actatropica.2009.09.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2009] [Revised: 08/31/2009] [Accepted: 09/08/2009] [Indexed: 10/20/2022]
Abstract
In order to verify whether chronic trypanosomal infections can affect the transmissibility of Trypanosoma congolense by tsetse flies, batches of Glossina morsitans morsitans were fed on mice infected with the same level of parasitemia (10(8.1)trypanosomes/ml of blood) of two cloned low virulent T. congolense strains during the acute and the chronic phases of infection. Results showed that the proportions of procyclic infections in flies that were fed during the acute phase (32.6% and 45.4% for isolates 1 and 2, respectively) were significantly higher (chi(2)=4.7, P<0.05 and chi(2)=23.7, P<0.0001, respectively) compared to the proportions of procyclic infections of flies fed during the chronic phase of infection (18.8% and 14.9% for isolates 1 and 2, respectively). Similarly the proportions of metacyclic infections in flies fed during the acute phase (32.6% and 45.4% for isolates 1 and 2, respectively) were significantly higher (chi(2)=6.3, P<0.05 and chi(2)=23.7, P<0.0001, respectively) compared to the proportions of metacyclic infections in flies fed during the chronic phase of infection (16.8% and 14.9% for isolates 1 and 2, respectively). No significant difference was found in the maturation rate of both strains during the acute phase compared to the chronic phase of infection (P>0.05). The results of this study suggest that T. congolense loses part of its transmissiblity by tsetse flies during the chronic phase of infection.
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Morrison LJ, Tait A, McLellan S, Sweeney L, Turner CMR, MacLeod A. A major genetic locus in Trypanosoma brucei is a determinant of host pathology. PLoS Negl Trop Dis 2009; 3:e557. [PMID: 19956590 PMCID: PMC2780326 DOI: 10.1371/journal.pntd.0000557] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2009] [Accepted: 10/22/2009] [Indexed: 11/18/2022] Open
Abstract
The progression and variation of pathology during infections can be due to components from both host or pathogen, and/or the interaction between them. The influence of host genetic variation on disease pathology during infections with trypanosomes has been well studied in recent years, but the role of parasite genetic variation has not been extensively studied. We have shown that there is parasite strain-specific variation in the level of splenomegaly and hepatomegaly in infected mice and used a forward genetic approach to identify the parasite loci that determine this variation. This approach allowed us to dissect and identify the parasite loci that determine the complex phenotypes induced by infection. Using the available trypanosome genetic map, a major quantitative trait locus (QTL) was identified on T. brucei chromosome 3 (LOD = 7.2) that accounted for approximately two thirds of the variance observed in each of two correlated phenotypes, splenomegaly and hepatomegaly, in the infected mice (named TbOrg1). In addition, a second locus was identified that contributed to splenomegaly, hepatomegaly and reticulocytosis (TbOrg2). This is the first use of quantitative trait locus mapping in a diploid protozoan and shows that there are trypanosome genes that directly contribute to the progression of pathology during infections and, therefore, that parasite genetic variation can be a critical factor in disease outcome. The identification of parasite loci is a first step towards identifying the genes that are responsible for these important traits and shows the power of genetic analysis as a tool for dissecting complex quantitative phenotypic traits. Trypanosomes are single-celled organisms that are transmitted between animal hosts by the tsetse fly. These parasites infect a wide range of mammals and in sub-Saharan Africa are extensively debilitating to livestock, and some species are also able to infect humans causing a disease, sleeping sickness, that is usually fatal unless treated. Some trypanosome strains cause more severe disease than others, and studying these differences may allow the identification of how serious disease is caused. We approached this problem by looking at how differences in disease symptoms (enlarged spleen and liver, and reduced blood cell numbers) that are caused in infections in mice with two strains of Trypanosoma brucei, TREU927 and STIB247. These disease manifestations are clinically relevant in human and livestock trypanosome infections. Examining how the symptoms are inherited in infections with offspring of a cross between the two strains allowed the identification of a region of the T. brucei genome that contains a gene (or several genes) that contributes significantly towards the enlarged spleen and liver observed in infected mice. This is a first step towards identifying the parasite genes that cause disease in the host (virulence factors), which may provide routes for developing novel therapies against the disease.
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Affiliation(s)
- Liam J Morrison
- Wellcome Trust Centre for Molecular Parasitology, University of Glasgow, Biomedical Research Centre, Glasgow, United Kingdom.
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34
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Cross-protection between Trypanosoma congolense strains of low and high virulence. Vet Parasitol 2009; 163:127-31. [PMID: 19423225 PMCID: PMC2771272 DOI: 10.1016/j.vetpar.2009.04.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2009] [Revised: 04/01/2009] [Accepted: 04/02/2009] [Indexed: 11/21/2022]
Abstract
The aim of this study was to assess the existence of possible cross-protection between Trypanosoma congolense strains of low and extreme virulence circulating in the same trypanosomiasis focus. Groups of six mice were infected using one of three strains of low virulence and challenged with one of three strains of extreme virulence. A group of six mice was used as control for each strain of low and extreme virulence. The results showed that mice infected with one of the strains of extreme virulence developed high parasitaemia and a significant drop of the PCV compared to mice infected with a strain of low virulence and challenged with one of the strains of extreme virulence. With an exception of one strain of extreme virulence (strain F), the survival time of mice infected with the strains of extreme virulence was shorter compared to mice infected with strains of low virulence and subsequently challenged with a strain of extreme virulence. These results suggest that in an area where trypanosomes of various virulence profiles circulate, livestock infected with T. congolense strains of low virulence can be protected against the adverse effects of extremely virulent T. congolense strains.
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35
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Masumu J, Geysen D, Van den Bossche P. Endemic type of animal trypanosomiasis is not associated with lower genotype variability of Trypanosoma congolense isolates circulating in livestock. Res Vet Sci 2009; 87:265-9. [PMID: 19356778 PMCID: PMC2771274 DOI: 10.1016/j.rvsc.2009.03.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2008] [Revised: 02/13/2009] [Accepted: 03/02/2009] [Indexed: 11/29/2022]
Abstract
In order to verify whether the low impact on livestock production in endemic areas is related to a low number of trypanosome strains circulating in livestock, 37 Trypanosoma congolense isolates collected from cattle in 11 sites in an endemic trypanosomiasis area in Eastern Zambia were characterised for genotype variability using a modified amplified fragment length polymorphism technique (AFLP). Isolates were further cloned to evaluate the occurrence of mixed infections in individuals. The results obtained revealed a high genotype diversity (94.6%) among these isolates. Apart from one site, all isolates gave different AFLP profiles in each of the sites. When clones were compared, three (8%) of the 37 isolates had mixed infections. These results indicate the circulation of a high number of strains in this trypanosomiasis endemic area despite the low impact the disease has on livestock production.
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Affiliation(s)
- J Masumu
- Department of Veterinary Tropical Diseases, University of Pretoria, Pretoria, Gauteng 0110, South Africa.
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36
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Trypanotolerance in small ruminants of sub-Saharan Africa. Trends Parasitol 2009; 25:132-8. [DOI: 10.1016/j.pt.2008.12.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2008] [Revised: 11/14/2008] [Accepted: 12/03/2008] [Indexed: 11/18/2022]
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37
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Simukoko H, Marcotty T, Phiri I, Geysen D, Vercruysse J, Van den Bossche P. The comparative role of cattle, goats and pigs in the epidemiology of livestock trypanosomiasis on the plateau of eastern Zambia. Vet Parasitol 2007; 147:231-8. [PMID: 17493757 PMCID: PMC2771273 DOI: 10.1016/j.vetpar.2007.04.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2006] [Revised: 03/30/2007] [Accepted: 04/03/2007] [Indexed: 11/04/2022]
Abstract
To determine and compare the prevalence of trypanosome infections in different livestock species (cattle, pigs and goats) in areas where game animals are scarce and livestock constitute the main food source of tsetse, a survey was conducted on the plateau of the Eastern Province of Zambia in Katete and Petauke districts where Glossina morsitans morsitans is the only tsetse species present. Blood was collected from a total of 734 cattle, 333 goats and 324 pigs originating from 59 villages in both districts and was examined using the buffy coat method and the PCR-RFLP as diagnostic tools. The prevalence of trypanosome infections differed substantially between livestock species. Using microscopic diagnostic methods, trypanosome infections were detected in 13.5% of the cattle and 0.9% of the pigs. All goats were parasitologically negative. The PCR-RFLP analyses increased the trypanosomiasis prevalence to 33.5, 6.5 and 3.3% in cattle, pigs and goats respectively. The majority of the infections (91.2%) were due to Trypanosoma congolense. The presence of a trypanosome infection in cattle and pigs resulted in a significant decline in the packed cell volume. The outcome of the study clearly shows that despite the availability of goats and pigs, cattle seem to be the major livestock species affected by the disease in trypanosomiasis endemic areas. The high proportion of infections in cattle could be partly attributed to their higher availability and attractiveness to tsetse.
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Affiliation(s)
- H. Simukoko
- University of Zambia, School of Veterinary Medicine, South Africa
| | - T. Marcotty
- Institute of Tropical Medicine, Animal Health Department, Nationalestraat 155, B-2000 Antwerp, Belgium
| | - I. Phiri
- University of Zambia, School of Veterinary Medicine, South Africa
| | - D. Geysen
- Institute of Tropical Medicine, Animal Health Department, Nationalestraat 155, B-2000 Antwerp, Belgium
| | - J. Vercruysse
- Ghent University, Vakgroep Virologie, parasitologie en Immunologie, Salisburylaan 133, B-9820 Merelbeke, Belgium
| | - P. Van den Bossche
- Institute of Tropical Medicine, Animal Health Department, Nationalestraat 155, B-2000 Antwerp, Belgium
- Department of Veterinary Tropical Diseases, University of Pretoria, Onderstepoort, South Africa
- Corresponding author. Institute of Tropical Medicine, Animal Health Department, Nationalestraat 155, 2000 Antwerp, Belgium Tel.: +32 3 2476396; fax: +32 3 2476268.
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Masumu J, Marcotty T, Ndeledje N, Kubi C, Geerts S, Vercruysse J, Dorny P, van den Bossche P. Comparison of the transmissibility ofTrypanosoma congolensestrains, isolated in a trypanosomiasis endemic area of eastern Zambia, byGlossina morsitans morsitans. Parasitology 2006; 133:331-4. [PMID: 16719960 DOI: 10.1017/s0031182006000369] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2006] [Revised: 03/05/2006] [Accepted: 03/09/2006] [Indexed: 11/07/2022]
Abstract
Transmission experiments were conducted to compare the transmissibility of genetically differentTrypanosoma congolense(Savannah subgroup) strains isolated from cattle in a trypanosomiasis endemic area of eastern Zambia. A total of 17 strains were compared. Three strains were extremely virulent with a short pre-patent period, high parasitaemia and a short median survival time (between 5 and 9 days) in mice. The remainder of the strains belonged to the moderate (6 strains) or low (8 strains) virulence categories with median survival times between 10 and 30 days and >30 days, respectively. Batches of 40 teneralGlossina morsitans morsitans(Diptera: Glossinidae) were offered a single bloodmeal on mice infected with one of those strains. Flies were dissected to determine their infection status 21 days later. The proportion of flies with procyclic and metacyclic infections differed significantly between trypanosome strains and were significantly higher in flies infected with extremely virulent strains (P=0·033 andP=0·016 for the differences in the procyclic infection rate of strains with moderate and low virulence, respectively andP=0·005 andP=0·019 for the differences in the metacyclic infection rate of strains with moderate and low virulence, respectively). On the other hand, moderately virulent strains had, in general, higher procyclic and metacyclic infection rates compared to low virulent strains. But the differences were not significant (P>0·05). The outcome of those experiments shows clear differences in transmissibility of trypanosome strains associated with their virulence. This observation confirms the theory for the evolution and maintenance of virulence in a parasite population and may explain the persistence of virulent trypanosome strains in a susceptible host population.
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Affiliation(s)
- J Masumu
- Institute of Tropical Medicine, Animal Health Department, Nationalestraat 155, B-2000 Antwerp, Belgium.
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