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Hadermann A, Jada SR, Sebit WJ, Deng T, Bol YY, Siewe Fodjo JN, De Coninck L, Matthijnssens J, Mertens I, Polman K, Colebunders R. Onchocerciasis-associated epilepsy: an explorative case-control study with viral metagenomic analyses on Onchocerca volvulus. F1000Res 2023; 12:1262. [PMID: 38439783 PMCID: PMC10911407 DOI: 10.12688/f1000research.138774.1] [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: 12/06/2023] [Indexed: 03/06/2024] Open
Abstract
Background A high prevalence of onchocerciasis-associated epilepsy (OAE) has been observed in onchocerciasis-endemic areas with high ongoing Onchocerca volvulus transmission. However, the pathogenesis of OAE remains to be elucidated. We hypothesise that the O. volvulus virome could be involved in inducing epilepsy. With this study, we aim to describe the O. volvulus virome and identify potential neurotropic viruses linked to OAE. Methods In Maridi County, an onchocerciasis endemic area in South Sudan with a high prevalence of OAE, we will conduct an exploratory case-control study enrolling 40 persons aged 12 years and above with palpable onchocerciasis nodules. Cases will be participants with OAE (n=20), who will be age- and village-matched with controls without epilepsy (n=20). For each study participant, two skin snips at the iliac crest will be obtained to collect O. volvulus microfilariae, and one nodulectomy will be performed to obtain adult worms. A viral metagenomic study will be conducted on microfilariae and adult worms, and the O. volvulus virome of persons with and without OAE will be compared. The number, size, and localisation of onchocerciasis nodules in persons with and without OAE will be described. Moreover, the pre- and post-nodulectomy frequency of seizures in persons with OAE will be compared. Ethics and dissemination The protocol has been approved by the Ethics Committee of the University of Antwerp and the Ministry of Health of South Sudan. Findings will be disseminated nationally and internationally via meetings and peer-reviewed publications. Registration ClinicalTrials.gov registration NCT05868551 ( https://clinicaltrials.gov/study/NCT05868551). Protocol version 1.1, dated 09/05/2023.
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Affiliation(s)
- Amber Hadermann
- Global Health Institute, University of Antwerp, Antwerp, 2610, Belgium
| | | | - Wilson J. Sebit
- Public Health Laboratory, Ministry of Health South Sudan, Juba, South Sudan
| | | | - Yak Y. Bol
- Neglected Tropical Diseases Unit, Ministry of Health South Sudan, Juba, South Sudan
| | | | - Lander De Coninck
- Laboratory of Viral Metagenomics, KU Leuven, Leuven, Flanders, 3000, Belgium
| | - Jelle Matthijnssens
- Laboratory of Viral Metagenomics, KU Leuven, Leuven, Flanders, 3000, Belgium
| | - Inge Mertens
- Health Unit, VITO (Vlaamse Instelling voor Technologisch Onderzoek), Mol, 2400, Belgium
- Centre for Proteomics, University of Atwerp, Antwerp, Belgium
| | - Katja Polman
- Department of Health Sciences, VU Amsterdam, Amsterdam, 1081, The Netherlands
- Department Public Health, Institute of Tropical Medicine, Antwerp, 2600, Belgium
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2
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Gaiya DD, Muhammad A, Aimola IA, Udu SK, Balarabe SA, Auta R, Ekpa E, Sheyin A. Potential of Onchocerca ochengi inosine-5'-monophosphate dehydrogenase (IMPDH) and guanosine-5'-monophosphate oxidoreductase (GMPR) as druggable and vaccine candidates: immunoinformatics screening. J Biomol Struct Dyn 2023; 41:14832-14848. [PMID: 36866624 DOI: 10.1080/07391102.2023.2184171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 02/18/2023] [Indexed: 03/04/2023]
Abstract
Onchocerciasis is a vector-borne disease caused by the filarial nematode Onchocerca volvulus, which is responsible for most of the visual impairments recorded in Africa, Asia and the Americas. It is known that O. volvulus has similar molecular and biological characteristics as Onchocerca ochengi in cattle. This study was designed to screen for immunogenic epitopes and binding pockets of O. ochengi IMPDH and GMPR ligands using immunoinformatic approaches. In this study, a total of 23 B cell epitopes for IMPDH and 7 B cell epitopes for GMPR were predicted using ABCpred tool, Bepipred 2.0 and Kolaskar and Tongaonkar methods. The CD4+ Th computational results showed 16 antigenic epitopes from IMPDH with strong binding affinity for DRB1_0301, DRB3_0101, DRB1_0103 and DRB1_1501 MHC II alleles while 8 antigenic epitopes from GMPR were predicted to bind DRB1_0101 and DRB1_0401 MHC II alleles, respectively. For the CD8+ CTLs analysis, 8 antigenic epitopes from IMPDH showed strong binding affinity to human leukocyte antigen HLA-A*26:01, HLA-A*03:01, HLA-A*24:02 and HLA-A*01:01 MHC I alleles while 2 antigenic epitopes from GMPR showed strong binding affinity to HLA-A*01:01 allele, respectively. The immunogenic B cell and T cell epitopes were further evaluated for antigenicity, non-alllergernicity, toxicity, IFN-gamma, IL4 and IL10. The docking score revealed favorable binding free energy with IMP and MYD scoring the highest binding affinity at -6.6 kcal/mol with IMPDH and -8.3 kcal/mol with GMPR. This study provides valuable insight on IMPDH and GMPR as potential drug targets and for the development of multiple epitope vaccine candidates.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Daniel Danladi Gaiya
- Biology Unit, Faculty of Science, Air Force Institute of Technology, Nigerian Air Force Base, Kawo, Kaduna State, Nigeria
| | - Aliyu Muhammad
- Department of Biochemistry, Faculty of Life Sciences, Ahmadu Bello University, Samaru Zaria, Kaduna State, Nigeria
| | - Idowu Asegame Aimola
- Department of Biochemistry, Faculty of Life Sciences, Ahmadu Bello University, Samaru Zaria, Kaduna State, Nigeria
| | - Stella Kuyet Udu
- Biology Unit, Faculty of Science, Air Force Institute of Technology, Nigerian Air Force Base, Kawo, Kaduna State, Nigeria
| | - Sallau Abdullahi Balarabe
- Department of Biochemistry, Faculty of Life Sciences, Ahmadu Bello University, Samaru Zaria, Kaduna State, Nigeria
| | - Richard Auta
- Department of Biochemistry, Faculty of Science, Kaduna State University, Kaduna, Kaduna State, Nigeria
| | - Emmanuel Ekpa
- Biology Unit, Faculty of Science, Air Force Institute of Technology, Nigerian Air Force Base, Kawo, Kaduna State, Nigeria
| | - Abraham Sheyin
- Department of Biochemistry, Faculty of Life Sciences, Ahmadu Bello University, Samaru Zaria, Kaduna State, Nigeria
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3
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Abraham D, Graham-Brown J, Carter D, Gray SA, Hess JA, Makepeace BL, Lustigman S. Development of a recombinant vaccine against human onchocerciasis. Expert Rev Vaccines 2021; 20:1459-1470. [PMID: 34488533 DOI: 10.1080/14760584.2021.1977125] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 09/02/2021] [Indexed: 01/02/2023]
Abstract
INTRODUCTION Human onchocerciasis caused by the filarial nematode parasite Onchocerca volvulus remains a major cause of debilitating disease infecting millions primarily in Sub-Saharan Africa. The development of a prophylactic vaccine, along with mass drug administration, would facilitate meeting the goal of onchocerciasis elimination by 2030. AREAS COVERED Models used to study immunity to Onchocerca include natural infection of cattle with Onchocerca ochengi and O. volvulus infective third-stage larvae implanted within diffusion chambers in mice. A vaccine, comprised of two adjuvanted recombinant antigens, induced protective immunity in genetically diverse mice suggesting that it will function similarly in diverse human populations. These antigens were recognized by immune humans and also induced protective immunity against Brugia malayi. We describe the development of a fusion protein composed of the two vaccine antigens with the plan to test the vaccine in cows and non-human primates as a prelude to the initiation of phase 1 clinical trials. EXPERT OPINION The adjuvanted O. volvulus vaccine composed of two antigens Ov-103 and Ov-RAL-2 was shown to be consistently effective at inducing protective immunity using multiple immune mechanisms. The vaccine is ready for further evaluation in other animal models before moving to clinical trials in humans.
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Affiliation(s)
- David Abraham
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - John Graham-Brown
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Liverpool, UK
| | | | | | - Jessica A Hess
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Benjamin L Makepeace
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Sara Lustigman
- Laboratory of Molecular Parasitology, Lindsley F. Kimball Research Institute, New York Blood Center, New York, NY, USA
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4
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Ngwasiri NN, Brattig NW, Ndjonka D, Liebau E, Paguem A, Leusder D, Kingsley MT, Eisenbarth A, Renz A, Daniel AM. Galectins from Onchocerca ochengi and O. volvulus and their immune recognition by Wistar rats, Gudali zebu cattle and human hosts. BMC Microbiol 2021; 21:5. [PMID: 33407120 PMCID: PMC7788699 DOI: 10.1186/s12866-020-02064-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 12/07/2020] [Indexed: 12/16/2022] Open
Abstract
Background During the last two decades research on animal filarial parasites, especially Onchocerca ochengi, infecting cattle in savanna areas of Africa revealed that O. ochengi as an animal model has biological features that are similar to those of O. volvulus, the aetiological agent of human onchocerciasis. There is, however, a paucity of biochemical, immunological and pathological data for O. ochengi. Galectins can be generated by parasites and their hosts. They are multifunctional molecules affecting the interaction between filarial parasites and their mammalian hosts including immune responses. This study characterized O. ochengi galectin, verified its immunologenicity and established its immune reactivity and that of Onchocerca volvulus galectin. Results The phylogenetic analysis showed the high degree of identity between the identified O. ochengi and the O. volvulus galectin-1 (ß-galactoside-binding protein-1) consisting only in one exchange of alanine for serine. O. ochengi galectin induced IgG antibodies during 28 days after immunization of Wistar rats. IgG from O. ochengi-infected cattle and O. volvulus-infected humans cross-reacted with the corresponding galectins. Under the applied experimental conditions in a cell proliferation test, O. ochengi galectin failed to significantly stimulate peripheral blood mononuclear cells (PBMCs) from O. ochengi-infected cattle, regardless of their parasite load. Conclusion An O. ochengi galectin gene was identified and the recombinantly expressed protein was immunogenic. IgG from Onchocerca-infected humans and cattle showed similar cross-reaction with both respective galectins. The present findings reflect the phylogenetic relationship between the two parasites and endorse the appropriateness of the cattle O. ochengi model for O. volvulus infection research. Supplementary Information The online version contains supplementary material available at 10.1186/s12866-020-02064-3.
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Affiliation(s)
| | - Norbert W Brattig
- Department Molecular Medicine, Bernhard Nocht Institute of Tropical Medicine, Hamburg, Germany
| | | | - Eva Liebau
- University of Muenster, Münster, Germany
| | - Archile Paguem
- University of Ngaoundéré, Ngaoundéré, Cameroon.,Department Comparative Zoology, Eberhard Karls University, Institute of Evolution and Ecology, Tübingen, Germany.,Department of Veterinary Medicine, University of Buea, Buea, Cameroon
| | | | - Manchang Tanyi Kingsley
- Department of Veterinary Medicine, University of Buea, Buea, Cameroon.,Veterinary Research Laboratory, IRAD Wakwa Regional Centre, Ngaoundéré, Cameroon
| | - Albert Eisenbarth
- Department Comparative Zoology, Eberhard Karls University, Institute of Evolution and Ecology, Tübingen, Germany.,Programme Onchocercoses, Station of the University of Tübingen, Ngaoundéré, Cameroon
| | - Alfons Renz
- Department Comparative Zoology, Eberhard Karls University, Institute of Evolution and Ecology, Tübingen, Germany.,Programme Onchocercoses, Station of the University of Tübingen, Ngaoundéré, Cameroon
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5
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Doyle SR, Sankaranarayanan G, Allan F, Berger D, Jimenez Castro PD, Collins JB, Crellen T, Duque-Correa MA, Ellis P, Jaleta TG, Laing R, Maitland K, McCarthy C, Moundai T, Softley B, Thiele E, Ouakou PT, Tushabe JV, Webster JP, Weiss AJ, Lok J, Devaney E, Kaplan RM, Cotton JA, Berriman M, Holroyd N. Evaluation of DNA Extraction Methods on Individual Helminth Egg and Larval Stages for Whole-Genome Sequencing. Front Genet 2019; 10:826. [PMID: 31616465 PMCID: PMC6764475 DOI: 10.3389/fgene.2019.00826] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 08/12/2019] [Indexed: 01/19/2023] Open
Abstract
Whole-genome sequencing is being rapidly applied to the study of helminth genomes, including de novo genome assembly, population genetics, and diagnostic applications. Although late-stage juvenile and adult parasites typically produce sufficient DNA for molecular analyses, these parasitic stages are almost always inaccessible in the live host; immature life stages found in the environment for which samples can be collected non-invasively offer a potential alternative; however, these samples typically yield very low quantities of DNA, can be environmentally resistant, and are susceptible to contamination, often from bacterial or host DNA. Here, we have tested five low-input DNA extraction protocols together with a low-input sequencing library protocol to assess the feasibility of whole-genome sequencing of individual immature helminth samples. These approaches do not use whole-genome amplification, a common but costly approach to increase the yield of low-input samples. We first tested individual parasites from two species spotted onto FTA cards-egg and L1 stages of Haemonchus contortus and miracidia of Schistosoma mansoni-before further testing on an additional five species-Ancylostoma caninum, Ascaridia dissimilis, Dirofilaria immitis, Strongyloides stercoralis, and Trichuris muris-with an optimal protocol. A sixth species-Dracunculus medinensis-was included for comparison. Whole-genome sequencing followed by analyses to determine the proportion of on- and off-target mapping revealed successful sample preparations for six of the eight species tested with variation both between species and between different life stages from some species described. These results demonstrate the feasibility of whole-genome sequencing of individual parasites, and highlight a new avenue toward generating sensitive, specific, and information-rich data for the diagnosis and surveillance of helminths.
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Affiliation(s)
- Stephen R. Doyle
- Parasites and Microbes, Wellcome Sanger Institute, Hinxton, United Kingdom
| | | | - Fiona Allan
- Department of Life Sciences, Natural History Museum, London, United Kingdom
| | - Duncan Berger
- Parasites and Microbes, Wellcome Sanger Institute, Hinxton, United Kingdom
| | - Pablo D. Jimenez Castro
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, United States
- Grupo de Parasitologia Veterinaria, Universidad Nacional de Colombia, Bogotá, Colombia
| | - James Bryant Collins
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, United States
| | - Thomas Crellen
- Parasites and Microbes, Wellcome Sanger Institute, Hinxton, United Kingdom
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | | | - Peter Ellis
- Parasites and Microbes, Wellcome Sanger Institute, Hinxton, United Kingdom
| | - Tegegn G. Jaleta
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Roz Laing
- Institute of Biodiversity Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Kirsty Maitland
- Institute of Biodiversity Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Catherine McCarthy
- Parasites and Microbes, Wellcome Sanger Institute, Hinxton, United Kingdom
| | | | - Ben Softley
- Parasites and Microbes, Wellcome Sanger Institute, Hinxton, United Kingdom
| | - Elizabeth Thiele
- Department of Biology, Vassar College, Poughkeepsie, NY, United States
| | | | - John Vianney Tushabe
- Parasites and Microbes, Wellcome Sanger Institute, Hinxton, United Kingdom
- Medical Research Council/Uganda Virus Research Institute and London School of Hygiene & Tropical Medicine Uganda Research Unit, Entebbe, Uganda
| | - Joanne P. Webster
- Centre for Emerging, Endemic and Exotic Diseases, Department of Pathology and Population Sciences, Royal Veterinary College, University of London, Herts, United Kingdom
| | - Adam J. Weiss
- Guinea Worm Eradication Program, The Carter Center, Atlanta, GA, United States
| | - James Lok
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Eileen Devaney
- Institute of Biodiversity Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Ray M. Kaplan
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, United States
| | - James A. Cotton
- Parasites and Microbes, Wellcome Sanger Institute, Hinxton, United Kingdom
| | - Matthew Berriman
- Parasites and Microbes, Wellcome Sanger Institute, Hinxton, United Kingdom
| | - Nancy Holroyd
- Parasites and Microbes, Wellcome Sanger Institute, Hinxton, United Kingdom
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6
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Neves MI, Webster JP, Walker M. Estimating helminth burdens using sibship reconstruction. Parasit Vectors 2019; 12:441. [PMID: 31522688 PMCID: PMC6745796 DOI: 10.1186/s13071-019-3687-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 08/28/2019] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Sibship reconstruction is a form of parentage analysis that can be used to identify the number of helminth parental genotypes infecting individual hosts using genetic data on only their offspring. This has the potential to be used for estimating individual worm burdens when adult parasites are otherwise inaccessible, the case for many of the most globally important human helminthiases and neglected tropical diseases. Yet methods of inferring worm burdens from sibship reconstruction data on numbers of unique parental genotypes are lacking, limiting the method's scope of application. RESULTS We developed a novel statistical method for estimating female worm burdens from data on the number of unique female parental genotypes derived from sibship reconstruction. We illustrate the approach using genotypic data on Schistosoma mansoni (miracidial) offspring collected from schoolchildren in Tanzania. We show how the bias and precision of worm burden estimates critically depends on the number of sampled offspring and we discuss strategies for obtaining sufficient sample sizes and for incorporating judiciously formulated prior information to improve the accuracy of estimates. CONCLUSIONS This work provides a novel approach for estimating individual-level worm burdens using genetic data on helminth offspring. This represents a step towards a wider scope of application of parentage analysis techniques. We discuss how the method could be used to assist in the interpretation of monitoring and evaluation data collected during mass drug administration programmes targeting human helminthiases and to help resolve outstanding questions on key population biological processes that govern the transmission dynamics of these neglected tropical diseases.
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Affiliation(s)
- M Inês Neves
- Department of Pathobiology and Population Sciences, Royal Veterinary College, University of London, Hawkshead Lane, Hatfield, UK. .,London Centre for Neglected Tropical Disease Research, London, UK.
| | - Joanne P Webster
- Department of Pathobiology and Population Sciences, Royal Veterinary College, University of London, Hawkshead Lane, Hatfield, UK.,London Centre for Neglected Tropical Disease Research, London, UK
| | - Martin Walker
- Department of Pathobiology and Population Sciences, Royal Veterinary College, University of London, Hawkshead Lane, Hatfield, UK.,London Centre for Neglected Tropical Disease Research, London, UK
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7
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Abstract
The Wolbachia endosymbionts encompass a large group of intracellular bacteria of biomedical and veterinary relevance, closely related to Anaplasma, Ehrlichia, and Rickettsia. This genus of Gram-negative members of the Alphaproteobacteria does not infect vertebrates but is instead restricted to ecdysozoan species, including terrestrial arthropods and a family of parasitic filarial nematodes, the Onchocercidae. The Wolbachia profoundly impact not only the ecology and evolution but also the reproductive biology of their hosts, through a wide range of symbiotic interactions. Because they are essential to the survival and reproduction of their filarial nematode hosts, they represent an attractive target to fight filariasis. Their abilities to spread through insect populations and to affect vector competence through pathogen protection have made Wolbachia a staple for controlling vector-borne diseases. Estimated to be present in up to 66% of insect species, the Wolbachia are probably the most abundant endosymbionts on earth. Their success resides in their unique capacity to infect and manipulate the host germ line to favor their vertical transmission through the maternal lineage. Because the Wolbachia resist genetic manipulation and growth in axenic culture, our understanding of their biology is still in its infancy. Despite these limitations, the "-omics" revolution combined with the use of well-established and emerging experimental host models is accelerating our comprehension of the host phenotypes caused by Wolbachia, and the identification of Wolbachia effectors is ongoing.
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8
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Yilmaz E, Wongkamchai S, Ramünke S, Koutsovoulos GD, Blaxter ML, Poppert S, Schaper R, von Samson-Himmelstjerna G, Krücken J. High genetic diversity in the Dirofilaria repens species complex revealed by mitochondrial genomes of feline microfilaria samples from Narathiwat, Thailand. Transbound Emerg Dis 2018; 66:389-399. [PMID: 30281949 DOI: 10.1111/tbed.13033] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 09/10/2018] [Accepted: 09/24/2018] [Indexed: 11/28/2022]
Abstract
Dirofilaria repens is a zoonotic, mosquito-borne filaria infecting carnivores, particularly dogs. It is expanding its range in Europe but epidemiological information is sparse for other Eurasian regions. In Hong Kong and India, the closely related species Candidatus Dirofilaria hongkongensis was proposed. Previous analysis of 2.5 kb partial mitochondrial genome sequences containing the particularly variable non-coding control region revealed low diversity in European D. repens while Asian nematodes showed high diversity. Sequences derived from feline blood samples from Narathiwat (Thailand) led to the proposal of a third potential species, Dirofilaria sp. "Thailand II". To avoid bias from rapidly evolving non-coding regions, this study aimed to compare Dirofilaria sp. "Thailand II" with D. repens and C. D. hongkongensis based on complete mitochondrial genomes. Using PCRs and Sanger sequencing, three complete mitochondrial genomes (13,651 bp) were assembled from DNA obtained from different feline blood samples. Mitochondrial genome organization was identical to other onchocercids with eleven protein-coding, two rRNA and 22 tRNA genes and no atp-8 gene. All genes were on the same strand showing an extremely high thymidine content (56.7%). Maximum-likelihood phylogenetic analysis using protein and rRNA sequences confirmed closer relationship of Dirofilaria sp. "Thailand II" to C. D. hongkongensis than to D. repens. All distances between these three putative species were considerably larger than the distance between the valid sibling species Onchocerca volvulus and Onchocerca ochengi. Sequencing of a 2.5 kb fragment containing the control region from microfilarial DNA from additional feline blood samples from Narathiwat 3-4 years later revealed that these also fell into the C. D. hongkongensis clade but were remarkably different from C. D. hongkongensis and Dirofilaria sp. "Thailand II". Since D. repens-like filaria are absent from dogs in Narathiwat, further field studies are required to confirm if these genotypes represent locally circulating cat-specific Dirofilaria genotypes or species.
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Affiliation(s)
- Esra Yilmaz
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Sirichit Wongkamchai
- Department of Parasitology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Sabrina Ramünke
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Georgios D Koutsovoulos
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Mark L Blaxter
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK.,The GenePool Genomics Facility, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Sven Poppert
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | | | | | - Jürgen Krücken
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
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9
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Ramünke S, de Almeida Borges F, von Son-de Fernex E, von Samson-Himmelstjerna G, Krücken J. Molecular marker sequences of cattle Cooperia species identify Cooperia spatulata as a morphotype of Cooperia punctata. PLoS One 2018; 13:e0200390. [PMID: 29979783 PMCID: PMC6034896 DOI: 10.1371/journal.pone.0200390] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Accepted: 06/25/2018] [Indexed: 12/13/2022] Open
Abstract
The genus Cooperia includes important parasites of ruminants and currently contains 34 accepted species. However, even for those species infecting livestock, there is a considerable lack of molecular information and many species are only identifiable using subtle morphological traits. The present study aimed to provide molecular data to allow diagnosis of Cooperia species infecting cattle. Partial sequences of two mitochondrial (cytochrome oxidase 2, 12S rRNA gene) and two nuclear genes (isotype 1 β tubulin gene including two introns, internal transcribed spacers (ITS) were obtained from morphologically identified specimens of Cooperia pectinata, Cooperia punctata and Cooperia spatulata as well as from larvae of pure Cooperia oncophora and C. punctata laboratory isolates. Pairwise identity of ITS-2 sequences was very high and it was the only region able to identify a specimen as Cooperia sp. However, the ITS-2 was unreliable for diagnosis at the species level. All other marker sequences could not unequivocally be allocated to the genus Cooperia but allowed clear species identification with the exception of the pair C. punctata/C. spatulata for which no significant differences were found for any marker sequence. Maximum-likelihood phylogenetic analyses of individual genes as well as a multi-locus analysis covering all four sequences confirmed that specimen identified as C. spatulata were randomly distributed throughout the C. punctata cluster and formed no group of their own. In contrast, the other Cooperia species formed clearly separated and statistically supported clusters. These data indicate that C. spatulata is most likely only a morphotype of C. punctata and the name should be considered a synonym. Combinations of nuclear and mitochondrial markers should be used to identify morphotypes or cryptic species to benefit from excellent barcoding properties of the latter but allowing proper phylogenetic analyses and controlling for lineage sorting that might occur for mitochondrial genotypes within a species.
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Affiliation(s)
- Sabrina Ramünke
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | | | - Elke von Son-de Fernex
- Centro de Enseñanza Investigación y Extensión en Ganadería Tropical, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, H. Tlapacoyan, Veracruz, México
| | | | - Jürgen Krücken
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
- * E-mail:
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10
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Full mitochondrial and nuclear genome comparison confirms that Onchocerca sp. "Siisa" is Onchocerca ochengi. Parasitol Res 2018; 117:1069-1077. [PMID: 29404746 PMCID: PMC5978932 DOI: 10.1007/s00436-018-5783-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Accepted: 01/23/2018] [Indexed: 11/01/2022]
Abstract
Onchocerca ochengi is a nodule-forming filarial nematode parasite of cattle. It is the closest known relative of the human parasite Onchocerca volvulus, with which it shares the black fly vector Simulium damnosum. Onchocerca sp. "Siisa" was described in black flies and in cattle and, based on limited mitochondrial sequence information, appeared to be about equally phylogenetically distant from O. ochengi and O. volvulus. Based on molecular genetic markers and apparent interbreeding, we later proposed that O. sp. "Siisa" belongs to the species O. ochengi. However, we did not demonstrate directly that the hybrids were fertile, and we were still unable to resolve the phylogenetic relationship of O. ochengi, O. sp. "Siisa," and O. volvulus, leaving some concerns with the conclusion mentioned above. Here, we present fully assembled, manually curated mitochondrial genomes of O. ochengi and O. sp. "Siisa," and we compare multiple individuals of these two taxa with respect to their whole mitochondrial and nuclear genomes. Based on the mitochondrial genomes, O. ochengi and O. sp. "Siisa" are phylogenetically much closer to each other than to O. volvulus. The differences between them are well within the range of what is expected for within-species variation. The nuclear genome comparison provided no indication of genetic separation of O. ochengi and O. sp. "Siisa." From this, in combination with the earlier literature, we conclude that O. ochengi and O. sp. "Siisa" should be considered one species.
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Yilmaz E, Fritzenwanker M, Pantchev N, Lendner M, Wongkamchai S, Otranto D, Kroidl I, Dennebaum M, Le TH, Anh Le T, Ramünke S, Schaper R, von Samson-Himmelstjerna G, Poppert S, Krücken J. The Mitochondrial Genomes of the Zoonotic Canine Filarial Parasites Dirofilaria (Nochtiella) repens and Candidatus Dirofilaria (Nochtiella) hongkongensis Provide Evidence for Presence of Cryptic Species. PLoS Negl Trop Dis 2016; 10:e0005028. [PMID: 27727270 PMCID: PMC5058507 DOI: 10.1371/journal.pntd.0005028] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 09/09/2016] [Indexed: 11/18/2022] Open
Abstract
Background Cutaneous dirofilariosis is a canine mosquito-borne zoonosis that can cause larva migrans disease in humans. Dirofilaria repens is considered an emerging pathogen occurring with high prevalence in Mediterranean areas and many parts of tropical Asia. In Hong Kong, a second species, Candidatus Dirofilaria hongkongensis, has been reported. The present study aimed to compare mitochondrial genomes from these parasites and to obtain population genetic information. Methods and Findings Complete mitochondrial genomes were obtained by PCR and Sanger sequencing or ILLUMINA sequencing for four worms. Cytochrome oxidase subunit 1 sequences identified three as D. repens (all from Europe) and one as C. D. hongkongensis (from India). Mitochondrial genomes have the same organization as in other spirurid nematodes but a higher preference for thymine in the coding strand. Phylogenetic analysis was in contradiction to current taxonomy of the Onchocercidae but in agreement with a recent multi-locus phylogenetic analysis using both mitochondrial and nuclear markers. D. repens and C. D. hongkongensis sequences clustered together and were the common sister group to Dirofilaria immitis. Analysis of a 2.5 kb mitochondrial genome fragment from macrofilaria or canine blood samples from Europe (42), Thailand (2), India (1) and Vietnam (1) revealed only small genetic differences in the D. repens samples including all European and the Vietnam sample. The Indian C. D. hongkongensis and the two Thai samples formed separate clusters and differences were comparatively large. Conclusion Genetic differences between Dirofilaria spp. causing cutaneous disease can be considerable whereas D. repens itself was genetically quite homogenous. C. D. hongkongensis was identified for the first time from the Indian subcontinent. The full mitochondrial genome sequence strengthens the hypothesis that it represents an independent species and the Thai samples might represent another cryptic species, Candidatus Dirofilaria sp. ‘Thailand II’, or a quite divergent population of C. D. hongkongensis. The mitochondrial genomes of the zoonotic parasite species Dirofilaria repens and Candidatus Dirofilaria hongkongensis were characterized and compared to the genomes of other filariae. The resulting phylogeny is largely in agreement with recent molecular data. C. D. hongkongensis was placed as a sister group to D. repens and both as a common sister to D. immitis. The large genetic difference between D. repens and C. D. hongkongensis further supports the hypothesis that both are distinct valid species. Two canine samples from Thailand that were diagnosed as D. repens are either from a C. D. hongkongensis population that is quite divergent from the Indian population or might represent another currently unrecognized species in the genus.
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Affiliation(s)
- Esra Yilmaz
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Moritz Fritzenwanker
- Institute of Medical Microbiology, Justus-Liebig-University, Giessen, Germany; German Center for Infection Research (DZIF), Partner site Giessen-Marburg-Langen, Campus Giessen, Giessen, Germany
| | | | - Mathias Lendner
- Institut für Parasitologie, Universität Leipzig, Leipzig, Germany
| | - Sirichit Wongkamchai
- Department of Parasitology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Domenico Otranto
- Department of Veterinary Medicine, University of Bari, Bari, Italy
| | - Inge Kroidl
- Division of Infectious Diseases and Tropical Medicine, Medical Centre of the University of Munich (LMU); German Center for Infection Research (DZIF), Partner site Munich, Germany
| | - Martin Dennebaum
- Section Clinical Tropical Medicine, Department of Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Thanh Hoa Le
- Immunology Department, Institute of Biotechnology, Ha Noi, Viet Nam
| | - Tran Anh Le
- Department of Parasitology, Viet Nam Veterinary Medical University, Ha Noi, Viet Nam
| | - Sabrina Ramünke
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | | | | | - Sven Poppert
- University Medical Center, Hamburg-Eppendorf, Germany
| | - Jürgen Krücken
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
- * E-mail:
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25 Years of the Onchocerca ochengi Model. Trends Parasitol 2016; 32:966-978. [PMID: 27665524 DOI: 10.1016/j.pt.2016.08.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 08/20/2016] [Accepted: 08/30/2016] [Indexed: 01/12/2023]
Abstract
Although of limited veterinary significance, Onchocerca ochengi has become famous as a natural model or 'analogue' of human onchocerciasis (river blindness), which is caused by Onchocerca volvulus. On the basis of both morphological and molecular criteria, O. ochengi is the closest extant relative of O. volvulus and shares several key natural history traits with the human pathogen. These include exploitation of the same group of insect vectors (blackflies of the Simulium damnosum complex) and formation of collagenous nodules with a similar histological structure to human nodules. Here, we review the contribution of this natural system to drug and vaccine discovery efforts, as well as to our basic biological understanding of Onchocerca spp., over the past quarter-century.
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Eisenbarth A, Achukwi MD, Renz A. Ongoing Transmission of Onchocerca volvulus after 25 Years of Annual Ivermectin Mass Treatments in the Vina du Nord River Valley, in North Cameroon. PLoS Negl Trop Dis 2016; 10:e0004392. [PMID: 26926855 PMCID: PMC4771805 DOI: 10.1371/journal.pntd.0004392] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 12/28/2015] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Recent reports of transmission interruption of Onchocerca volvulus, the causing agent of river blindness, in former endemic foci in the Americas, and more recently in West and East Africa, raise the question whether elimination of this debilitating disease is underway after long-term treatment of the population at risk with ivermectin. The situation in Central Africa has not yet been clearly assessed. METHODS AND FINDINGS Entomologic data from two former endemic river basins in North Cameroon were generated over a period of 43 and 48 months to follow-up transmission levels in areas under prolonged ivermectin control. Moreover, epidemiologic parameters of animal-borne Onchocerca spp. transmitted by the same local black fly vectors of the Simulium damnosum complex were recorded and their impact on O. volvulus transmission success evaluated. With mitochondrial DNA markers we unambiguously confirmed the presence of infective O. volvulus larvae in vectors from the Sudan savannah region (mean Annual Transmission Potential 2009-2012: 98, range 47-221), but not from the Adamawa highland region. Transmission rates of O. ochengi, a parasite of Zebu cattle, were high in both foci. CONCLUSIONS/SIGNIFICANCE The high cattle livestock density in conjunction with the high transmission rates of the bovine filaria O. ochengi prevents the transmission of O. volvulus on the Adamawa plateau, whereas transmission in a former hyperendemic focus was markedly reduced, but not completely interrupted after 25 years of ivermectin control. This study may be helpful to gauge the impact of the presence of animal-filariae for O. volvulus transmission in terms of the growing human and livestock populations in sub-Saharan countries.
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Affiliation(s)
- Albert Eisenbarth
- Institute of Evolution and Ecology, Department of Comparative Zoology, University of Tübingen, Tübingen, Germany
- Programme Onchocercoses field station of the University of Tübingen, Ngaoundéré, Cameroon
| | - Mbunkah Daniel Achukwi
- Veterinary research laboratory, Institute of Agricultural Research for Development, Wakwa Regional Centre, Ngaoundéré, Cameroon
| | - Alfons Renz
- Institute of Evolution and Ecology, Department of Comparative Zoology, University of Tübingen, Tübingen, Germany
- * E-mail:
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