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Chunda VC, Fombad FF, Kien CA, Ebai R, Esofi F, Ntuh AN, Ouam E, Gandjui NVT, Ekanya R, Nietcho F, Nchang LC, Magha C, Njouendou AJ, Enyong P, Hoerauf A, Wanji S, Ritter M. Comparative development of human filariae Loa loa, Onchocerca volvulus and Mansonella perstans in immunocompromised mouse strains. FRONTIERS IN TROPICAL DISEASES 2024; 5:1293632. [PMID: 38655273 PMCID: PMC7615855 DOI: 10.3389/fitd.2024.1293632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024] Open
Abstract
Introduction Mouse models of human filarial infections are not only urgently needed to investigate the biology of the nematodes and their modulation of the host's immunity, but will also provide a platform to screen and test novel anti-filarial drugs. Recently, murine Loa loa infection models have been stablished using immunocompromised mouse strains, whereas murine Mansonella perstans infections have not been implemented until now. Methods Therefore, we aim to establish experimental M. perstans infections using the immunocompromised mouse strains RAG2IL-2Rγ-/- (lack B, T and natural killer cells), IL-4Rα/IL-5-/- (impaired IL-4/5 signalling and eosinophil activation) and NOD.Cg-PrkdcscidIl2rgtm1Wj l/SzJ (NOD scid gamma, NSG) BALB/c mice (lack mature lymphocytes) through subcutaneous (s.c.) or intraperitoneal (i.p.) inoculation of infective stage 3 larvae (L3) isolated from engorged vectors. Results In total, 145 immunocompromised mice have been inoculated with 3,250 M. perstans, 3,337 O. volvulus, and 2,720 Loa loa L3 to comparatively analyse which immunocompromised mouse strain is susceptible to human filarial infections. Whereas, no M. perstans and O. volvulus L3 could be recovered upon 2-63 days post-inoculation, a 62-66% Loa loa L3 recovery rate could be achieved in the different mouse strains. Gender of mice, type of inoculation (s.c. or i.p.) or time point of analysis (2-63 days post inoculation) did not interfere with the success of L3 recovery. In addition, administration of the immune suppressants hydrocortisone, prednisolone and cyclophosphamide did not restore M. perstans L3 recovery rates. Discussion These findings show that RAG2IL-2Rg-/-BALB/c and C57BL/6, IL-4Rα/IL-5-/- BALB/c and NSG mice were not susceptible to M. perstans and O. volvulus L3 inoculation using the applied methods, whereas Loa loa infection could be maintained. Further studies should investigate if humanized immunocompromised mice might be susceptible to M. perstans. and O. volvulus.
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Affiliation(s)
- Valerine C. Chunda
- Parasite and Vector Research Unit (PAVRU), Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
- Research Foundation for Tropical Diseases and the Environment (REFOTDE), Buea, Cameroon
| | - Fanny Fri Fombad
- Parasite and Vector Research Unit (PAVRU), Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
- Research Foundation for Tropical Diseases and the Environment (REFOTDE), Buea, Cameroon
| | - Chi Anizette Kien
- Parasite and Vector Research Unit (PAVRU), Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
- Research Foundation for Tropical Diseases and the Environment (REFOTDE), Buea, Cameroon
| | - Rene Ebai
- Parasite and Vector Research Unit (PAVRU), Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
- Research Foundation for Tropical Diseases and the Environment (REFOTDE), Buea, Cameroon
| | - Frederick Esofi
- Parasite and Vector Research Unit (PAVRU), Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
- Research Foundation for Tropical Diseases and the Environment (REFOTDE), Buea, Cameroon
| | - Anna Ning Ntuh
- Parasite and Vector Research Unit (PAVRU), Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
- Research Foundation for Tropical Diseases and the Environment (REFOTDE), Buea, Cameroon
| | - Emmanuel Ouam
- Parasite and Vector Research Unit (PAVRU), Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
- Research Foundation for Tropical Diseases and the Environment (REFOTDE), Buea, Cameroon
| | - Narcisse Victor Tchamatchoua Gandjui
- Parasite and Vector Research Unit (PAVRU), Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
- Research Foundation for Tropical Diseases and the Environment (REFOTDE), Buea, Cameroon
| | - Relindis Ekanya
- Parasite and Vector Research Unit (PAVRU), Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
- Research Foundation for Tropical Diseases and the Environment (REFOTDE), Buea, Cameroon
| | - Franck Nietcho
- Parasite and Vector Research Unit (PAVRU), Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
- Research Foundation for Tropical Diseases and the Environment (REFOTDE), Buea, Cameroon
| | - Lucy Cho Nchang
- Parasite and Vector Research Unit (PAVRU), Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
- Research Foundation for Tropical Diseases and the Environment (REFOTDE), Buea, Cameroon
| | - Chefor Magha
- Parasite and Vector Research Unit (PAVRU), Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
- Research Foundation for Tropical Diseases and the Environment (REFOTDE), Buea, Cameroon
| | - Abdel Jelil Njouendou
- Parasite and Vector Research Unit (PAVRU), Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
- Research Foundation for Tropical Diseases and the Environment (REFOTDE), Buea, Cameroon
| | - Peter Enyong
- Parasite and Vector Research Unit (PAVRU), Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
- Research Foundation for Tropical Diseases and the Environment (REFOTDE), Buea, Cameroon
| | - Achim Hoerauf
- Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn (UKB), Bonn, Germany
- German Centre for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, Germany
- German-West African Centre for Global Health and Pandemic Prevention (G-WAC), Partner Site Bonn, Bonn, Germany
| | - Samuel Wanji
- Parasite and Vector Research Unit (PAVRU), Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
- Research Foundation for Tropical Diseases and the Environment (REFOTDE), Buea, Cameroon
| | - Manuel Ritter
- Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn (UKB), Bonn, Germany
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Pfarr KM, Krome AK, Al-Obaidi I, Batchelor H, Vaillant M, Hoerauf A, Opoku NO, Kuesel AC. The pipeline for drugs for control and elimination of neglected tropical diseases: 1. Anti-infective drugs for regulatory registration. Parasit Vectors 2023; 16:82. [PMID: 36859332 PMCID: PMC9979492 DOI: 10.1186/s13071-022-05581-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 11/05/2022] [Indexed: 03/03/2023] Open
Abstract
The World Health Organization 'Ending the neglect to attain the Sustainable Development Goals: A road map for neglected tropical diseases 2021-2030' outlines the targets for control and elimination of neglected tropical diseases (NTDs). New drugs are needed to achieve some of them. We are providing an overview of the pipeline for new anti-infective drugs for regulatory registration and steps to effective use for NTD control and elimination. Considering drugs approved for an NTD by at least one stringent regulatory authority: fexinidazole, included in WHO guidelines for Trypanosoma brucei gambiense African trypanosomiasis, is in development for Chagas disease. Moxidectin, registered in 2018 for treatment of individuals ≥ 12 years old with onchocerciasis, is undergoing studies to extend the indication to 4-11-year-old children and obtain additional data to inform WHO and endemic countries' decisions on moxidectin inclusion in guidelines and policies. Moxidectin is also being evaluated for other NTDs. Considering drugs in at least Phase 2 clinical development, a submission is being prepared for registration of acoziborole as an oral treatment for first and second stage T.b. gambiense African trypanosomiasis. Bedaquiline, registered for tuberculosis, is being evaluated for multibacillary leprosy. Phase 2 studies of emodepside and flubentylosin in O. volvulus-infected individuals are ongoing; studies for Trichuris trichuria and hookworm are planned. A trial of fosravuconazole in Madurella mycetomatis-infected patients is ongoing. JNJ-64281802 is undergoing Phase 2 trials for reducing dengue viral load. Studies are ongoing or planned to evaluate oxantel pamoate for onchocerciasis and soil-transmitted helminths, including Trichuris, and oxfendazole for onchocerciasis, Fasciola hepatica, Taenia solium cysticercosis, Echinococcus granulosus and soil-transmitted helminths, including Trichuris. Additional steps from first registration to effective use for NTD control and elimination include country registrations, possibly additional studies to inform WHO guidelines and country policies, and implementation research to address barriers to effective use of new drugs. Relative to the number of people suffering from NTDs, the pipeline is small. Close collaboration and exchange of experience among all stakeholders developing drugs for NTDs may increase the probability that the current pipeline will translate into new drugs effectively implemented in affected countries.
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Affiliation(s)
- Kenneth M. Pfarr
- grid.15090.3d0000 0000 8786 803XInstitute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany ,grid.452463.2German Center for Infection Research, Partner Site Bonn-Cologne, Bonn, Germany
| | - Anna K. Krome
- grid.10388.320000 0001 2240 3300Department of Pharmaceutical Technology and Biopharmaceutics, University of Bonn, Bonn, Germany
| | - Issraa Al-Obaidi
- grid.11984.350000000121138138Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Hannah Batchelor
- grid.11984.350000000121138138Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Michel Vaillant
- grid.451012.30000 0004 0621 531XCompetence Center for Methodology and Statistics, Luxembourg Institute of Health, Strassen, Grand Duchy of Luxembourg
| | - Achim Hoerauf
- grid.15090.3d0000 0000 8786 803XInstitute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany ,grid.452463.2German Center for Infection Research, Partner Site Bonn-Cologne, Bonn, Germany
| | - Nicholas O. Opoku
- grid.449729.50000 0004 7707 5975Department of Epidemiology and Biostatistics School of Public Health, University of Health and Allied Sciences, Hohoe, Ghana
| | - Annette C. Kuesel
- UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases (WHO/TDR), World Health Organization, Geneva, Switzerland
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Dieki R, Nsi-Emvo E, Akue JP. The Human Filaria Loa loa: Update on Diagnostics and Immune Response. Res Rep Trop Med 2022; 13:41-54. [PMID: 35936385 PMCID: PMC9355020 DOI: 10.2147/rrtm.s355104] [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: 02/10/2022] [Accepted: 06/03/2022] [Indexed: 11/24/2022] Open
Abstract
Loa loa loiasis was considered an anecdotal disease 30 years ago. Its spread in Equatorial Africa and the side effects associated with mass drug administration programs against filariasis in co-endemic areas have drawn the attention of the international research community. Progress in research conducted to date has provided insight into the immunobiology of this parasite. An interesting finding reported in several studies is that 70% of individuals with loiasis do not carry microfilariae in their blood, and 30% are microfilaremic, suggesting the involvement of several immunological mechanisms, as shown by elevated specific IgG4 and IgE levels signifying a potential cross-linking mechanism between the two isotypes via L. loa antigen to prevent allergy. A mechanism of anergy in the appearance of microfilariae in the peripheral blood results in immunological unresponsiveness in individuals with microfilariae. There is an interaction between other pathogens (parasites, bacteria, viruses) in individuals co-infected with L. loa. The strong antigen cross-reactivity between L. loa and lymphatic filarial worms warrants a re-evaluation of the distribution of the latter in co-endemic regions. The mechanism of concomitant immunity observed in the elimination of microfilariae or infective larvae (third-stage larvae, L3) may be used for the conception of an immunoprophylactic strategy.
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Affiliation(s)
- Roland Dieki
- Department of Parasitology, International Centre of Medical Research of Franceville, Franceville, Gabon
- Department of Chemistry, Université des Sciences et Techniques de Masuku (USTM), Franceville, Gabon
| | - Edouard Nsi-Emvo
- Department of Chemistry, Université des Sciences et Techniques de Masuku (USTM), Franceville, Gabon
| | - Jean Paul Akue
- Department of Parasitology, International Centre of Medical Research of Franceville, Franceville, Gabon
- Correspondence: Jean Paul Akue, Department of Parasitology, International Centre of Medical Research of Franceville, Franceville, BP 769, Gabon, Email
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Description and molecular characterisation of Pelecitus copsychi Uni, Mat Udin & Martin n. sp. (Nematoda: Onchocercidae) from the white-rumped shama Copsychus malabaricus (Scopoli) (Passeriformes: Muscicapidae) of Pahang, Malaysia. CURRENT RESEARCH IN PARASITOLOGY & VECTOR-BORNE DISEASES 2022; 2:100078. [PMID: 36589876 PMCID: PMC9795348 DOI: 10.1016/j.crpvbd.2022.100078] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/21/2022] [Accepted: 01/24/2022] [Indexed: 01/04/2023]
Abstract
Species of the genus Pelecitus Railliet & Henry, 1910 the most widely distributed avian filariae in Africa and South America. Zoonotic cases in humans were reported in South America. While investigating the filarial fauna of wild animals in Malaysia, we discovered an undescribed filaria from the swollen footpad of the left leg of Copsychus malabaricus (Scopoli) in Pahang, Peninsular Malaysia. Adults of both sexes have a corkscrew-shaped body. Based on comparison of their morphological characteristics (i.e. pre-oesophageal cuticular ring distinct, oesophagus divided, vulva protuberant and situated at the level of anterior half of oesophagus, spicules strongly sclerotized and left spicule with broad blade) with other Pelecitus species, they are here described as Pelecitus copsychi Uni, Mat Udin & Martin n. sp. Multi-locus sequence analyses based on seven genes (12S rDNA, cox1, 18S rDNA, 28S rDNA, MyoHC, rbp1 and hsp70) were performed to determine the phylogenetic position of the new species. The calculated p-distance between the cox1 gene sequences for P. copsychi n. sp. and Pelecitus fulicaeatrae (Diesing, 1861) was 14.1%. Intraspecific genetic variation between two individuals of the new species was 0.4%. In both the Bayesian inference and maximum-likelihood trees, P. copsychi n. sp. was positioned in the second clade of ONC5, containing three genera of the subfamily Dirofilariinae (Foleyella Seurat, 1917, Pelecitus and Loa Stiles, 1905). Immunostaining and molecular analyses remained negative for the presence of Wolbachia endosymbionts. Our findings corroborate the division of the subfamily Dirofilariinae into ONC3 with Dirofilaria Railliet & Henry, 1911 and ONC5 with Pelecitus.
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Efon Ekangouo A, Nana Djeunga HC, Sempere G, Kamgno J, Njiokou F, Moundipa Fewou P, Geiger A. Bacteriome Diversity of Blackflies' Gut and Association with Onchocerca volvulus, the Causative Agent of Onchocerciasis in Mbam Valley (Center Region, Cameroon). Pathogens 2021; 11:pathogens11010044. [PMID: 35055992 PMCID: PMC8779297 DOI: 10.3390/pathogens11010044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 12/16/2021] [Accepted: 12/20/2021] [Indexed: 11/19/2022] Open
Abstract
Vector control using larvicides is the main alternative strategy to address limits of preventive chemotherapy using ivermectin for the control of onchocerciasis. However, it remains substantially limited by implementation difficulties, ecological concerns and the resistance of vector populations. Therefore, efficient and environmentally safe alternative control strategies are still needed. This study explores the composition of the blackfly bacteriome and its variability in the presence of Onchocerca volvulus infection, in order to determine their potential as a novel vector control-based approach to fight onchocerciasis. An entomological survey of a collection of samples was performed in the Bafia health district, a historical endemic focus for onchocerciasis in Cameroon. A total of 1270 blackflies were dissected and the infection rate was 10.1%, indicative of ongoing transmission of onchocerciasis in the surveyed communities. Sequencing process of blackflies’ gut DNA for bacteria screening revealed 14 phyla and 123 genera, highlighting the diversity of gut blackflies bacterial communities. Eight bacteria formed the core of blackfly bacteriome and Wolbachia was the predominant genus with 73.4% of relative abundance of blackflies’ gut bacterial communities. Acidomonas and Roseanomas genera were significantly abundant among infected blackflies (p = 0.01), whereas other genera such as Brevibacterium and Fructobacillus were associated with the absence of infection (p = 0.0009). Differences in gut bacterial distribution of blackflies according to their infection status by the parasite suggest a causal relationship between the bacteriome composition and the onset of blackflies’ infection by O. volvulus or vice versa. Blackfly native bacteria are then potentially involved in infection by O. volvulus, either by facilitating or preventing the parasite infestation of the vector. These bacteria represent an interesting potential as a biological tool/target for a novel approach of vector control to fight onchocerciasis.
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Affiliation(s)
- Arnauld Efon Ekangouo
- Centre for Research on Filariasis and other Tropical Diseases (CRFilMT), Yaoundé P.O. Box 5797, Cameroon; (A.E.E.); (J.K.); (A.G.)
- UMR InterTryp, IRD (Institut de Recherche Pour le Développement), University of Montpellier, F-34394 Montpellier, France;
- Department of Biochemistry, Faculty of Sciences, University of Yaoundé I, Yaoundé, Cameroon;
| | - Hugues C. Nana Djeunga
- Centre for Research on Filariasis and other Tropical Diseases (CRFilMT), Yaoundé P.O. Box 5797, Cameroon; (A.E.E.); (J.K.); (A.G.)
- Correspondence: ; Tel.: +237-699-076-499
| | - Guilhem Sempere
- UMR InterTryp, IRD (Institut de Recherche Pour le Développement), University of Montpellier, F-34394 Montpellier, France;
- South Green Bioinformatics Platform, Biodiversity, F-34934 Montpellier, France
- UMR InterTryp, CIRAD (Centre de Coopération Internationale en Recherche Agronomique Pour le Développement), Campus International de Baillarguet, F-34398 Montpellier, France
| | - Joseph Kamgno
- Centre for Research on Filariasis and other Tropical Diseases (CRFilMT), Yaoundé P.O. Box 5797, Cameroon; (A.E.E.); (J.K.); (A.G.)
- Faculty of Medicine and Biomedical Sciences, University of Yaoundé I, Yaoundé, Cameroon
| | - Flobert Njiokou
- Department of Animal Biology and Physiology, Faculty of Sciences, University of Yaoundé I, Yaoundé, Cameroon;
| | - Paul Moundipa Fewou
- Department of Biochemistry, Faculty of Sciences, University of Yaoundé I, Yaoundé, Cameroon;
| | - Anne Geiger
- Centre for Research on Filariasis and other Tropical Diseases (CRFilMT), Yaoundé P.O. Box 5797, Cameroon; (A.E.E.); (J.K.); (A.G.)
- UMR InterTryp, IRD (Institut de Recherche Pour le Développement), University of Montpellier, F-34394 Montpellier, France;
- Department of Animal Biology and Physiology, Faculty of Sciences, University of Yaoundé I, Yaoundé, Cameroon;
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Johnston KL, Hong WD, Turner JD, O'Neill PM, Ward SA, Taylor MJ. Anti-Wolbachia drugs for filariasis. Trends Parasitol 2021; 37:1068-1081. [PMID: 34229954 DOI: 10.1016/j.pt.2021.06.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 05/21/2021] [Accepted: 06/07/2021] [Indexed: 10/20/2022]
Abstract
The mutualistic association between Wolbachia endosymbionts and their filarial nematode hosts has been exploited as a validated drug target delivering macrofilaricidal outcomes. Limitations of existing antibiotics to scale-up have driven the search for new drugs, which are effective in shorter regimens of 7 days or less. Here, we review the last 14 years of anti-Wolbachia drug discovery by the anti-Wolbachia (A·WOL) consortium, which has screened more than two million compounds, delivering thousands of hit compounds. Refined screening models integrated with robust pharmacokinetic/pharmacodynamic (PK/PD) driven optimisation and selection strategies have delivered the first two drug candidates specifically designed to target Wolbachia. AWZ1066S and ABBV-4083 are currently progressing through clinical trials with the aim of delivering safe and effective macrofilaricides to support the elimination of onchocerciasis and lymphatic filariasis.
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Affiliation(s)
- Kelly L Johnston
- Centre for Neglected Tropical Diseases and Centre for Drugs and Diagnostics, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, UK; School of Life Sciences, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK
| | - W David Hong
- Department of Chemistry, University of Liverpool, Liverpool, UK
| | - Joseph D Turner
- Centre for Neglected Tropical Diseases and Centre for Drugs and Diagnostics, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Paul M O'Neill
- Department of Chemistry, University of Liverpool, Liverpool, UK
| | - Stephen A Ward
- Centre for Neglected Tropical Diseases and Centre for Drugs and Diagnostics, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Mark J Taylor
- Centre for Neglected Tropical Diseases and Centre for Drugs and Diagnostics, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, UK.
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Sandri TL, Kreidenweiss A, Cavallo S, Weber D, Juhas S, Rodi M, Woldearegai TG, Gmeiner M, Veletzky L, Ramharter M, Tazemda-Kuitsouc GB, Matsiegui PB, Mordmüller B, Held J. Molecular Epidemiology of Mansonella Species in Gabon. J Infect Dis 2021; 223:287-296. [PMID: 33099649 DOI: 10.1093/infdis/jiaa670] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 10/20/2020] [Indexed: 01/04/2023] Open
Abstract
Mansonella perstans, a filarial nematode, infects large populations in Africa and Latin America. Recently, a potential new species, Mansonella sp "DEUX," was reported. Carriage of endosymbiotic Wolbachia opens treatment options for Mansonella infections. Within a cross-sectional study, we assessed the prevalence of filarial infections in 834 Gabonese individuals and the presence of the endosymbiont Wolbachia. Almost half of the participants (400/834 [48%]) were infected with filarial nematodes, with Mansonella sp "DEUX" being the most frequent (295/400 [74%]), followed by Loa loa (273/400 [68%]) and Mansonella perstans (82/400 [21%]). Being adult/elderly, male, and living in rural areas was associated with a higher risk of infection. Wolbachia carriage was confirmed in M. perstans and Mansonella sp "DEUX." In silico analysis revealed that Mansonella sp "DEUX" is not detected with currently published M. perstans-specific assays. Mansonella infections are highly prevalent in Gabon and might have been underreported, likely also beyond Gabon.
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Affiliation(s)
- Thaisa Lucas Sandri
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany.,Laboratory of Molecular Immunopathology, Department of Clinical Pathology, Federal University of Paraná, Curitiba, Brazil
| | - Andrea Kreidenweiss
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany.,Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon.,German Center for Infection Research, partner site Tübingen, Tübingen, Germany
| | - Simon Cavallo
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - David Weber
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Sascha Juhas
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Miriam Rodi
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Tamirat Gebru Woldearegai
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany.,Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon.,German Center for Infection Research, partner site Tübingen, Tübingen, Germany
| | - Markus Gmeiner
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Luzia Veletzky
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon.,Department of Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine and I. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Michael Ramharter
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon.,Department of Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine and I. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | | | - Benjamin Mordmüller
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany.,Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon.,German Center for Infection Research, partner site Tübingen, Tübingen, Germany
| | - Jana Held
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany.,Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon.,German Center for Infection Research, partner site Tübingen, Tübingen, Germany
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Manoj RRS, Latrofa MS, Epis S, Otranto D. Wolbachia: endosymbiont of onchocercid nematodes and their vectors. Parasit Vectors 2021; 14:245. [PMID: 33962669 PMCID: PMC8105934 DOI: 10.1186/s13071-021-04742-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 04/23/2021] [Indexed: 12/19/2022] Open
Abstract
Background Wolbachia is an obligate intracellular maternally transmitted, gram-negative bacterium which forms a spectrum of endosymbiotic relationships from parasitism to obligatory mutualism in a wide range of arthropods and onchocercid nematodes, respectively. In arthropods Wolbachia produces reproductive manipulations such as male killing, feminization, parthenogenesis and cytoplasmic incompatibility for its propagation and provides an additional fitness benefit for the host to protect against pathogens, whilst in onchocercid nematodes, apart from the mutual metabolic dependence, this bacterium is involved in moulting, embryogenesis, growth and survival of the host. Methods This review details the molecular data of Wolbachia and its effect on host biology, immunity, ecology and evolution, reproduction, endosymbiont-based treatment and control strategies exploited for filariasis. Relevant peer-reviewed scientic papers available in various authenticated scientific data bases were considered while writing the review. Conclusions The information presented provides an overview on Wolbachia biology and its use in the control and/or treatment of vectors, onchocercid nematodes and viral diseases of medical and veterinary importance. This offers the development of new approaches for the control of a variety of vector-borne diseases. Graphic Abstract ![]()
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Affiliation(s)
| | | | - Sara Epis
- Department of Biosciences and Pediatric CRC 'Romeo Ed Enrica Invernizzi', University of Milan, Milan, Italy
| | - Domenico Otranto
- Department of Veterinary Medicine, University of Bari, Valenzano, Italy. .,Faculty of Veterinary Sciences, Bu-Ali Sina University, Hamedan, Iran.
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Bulman CA, Chappell L, Gunderson E, Vogel I, Beerntsen B, Slatko BE, Sullivan W, Sakanari JA. The Eagle effect in the Wolbachia-worm symbiosis. Parasit Vectors 2021; 14:118. [PMID: 33627171 PMCID: PMC7905570 DOI: 10.1186/s13071-020-04545-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 12/13/2020] [Indexed: 11/30/2022] Open
Abstract
Background Onchocerciasis (river blindness) and lymphatic filariasis (elephantiasis) are two human neglected tropical diseases that cause major disabilities. Mass administration of drugs targeting the microfilarial stage has reduced transmission and eliminated these diseases in several countries but a macrofilaricidal drug that kills or sterilizes the adult worms is critically needed to eradicate the diseases. The causative agents of onchocerciasis and lymphatic filariasis are filarial worms that harbor the endosymbiotic bacterium Wolbachia. Because filarial worms depend on Wolbachia for reproduction and survival, drugs targeting Wolbachia hold great promise as a means to eliminate these diseases. Methods To better understand the relationship between Wolbachia and its worm host, adult Brugia pahangi were exposed to varying concentrations of doxycycline, minocycline, tetracycline and rifampicin in vitro and assessed for Wolbachia numbers and worm motility. Worm motility was monitored using the Worminator system, and Wolbachia titers were assessed by qPCR of the single copy gene wsp from Wolbachia and gst from Brugia to calculate IC50s and in time course experiments. Confocal microscopy was also used to quantify Wolbachia located at the distal tip region of worm ovaries to assess the effects of antibiotic treatment in this region of the worm where Wolbachia are transmitted vertically to the microfilarial stage. Results Worms treated with higher concentrations of antibiotics had higher Wolbachia titers, i.e. as antibiotic concentrations increased there was a corresponding increase in Wolbachia titers. As the concentration of antibiotic increased, worms stopped moving and never recovered despite maintaining Wolbachia titers comparable to controls. Thus, worms were rendered moribund by the higher concentrations of antibiotics but Wolbachia persisted suggesting that these antibiotics may act directly on the worms at high concentration. Surprisingly, in contrast to these results, antibiotics given at low concentrations reduced Wolbachia titers. Conclusion Wolbachia in B. pahangi display a counterintuitive dose response known as the “Eagle effect.” This effect in Wolbachia suggests a common underlying mechanism that allows diverse bacterial and fungal species to persist despite exposure to high concentrations of antimicrobial compounds. To our knowledge this is the first report of this phenomenon occurring in an intracellular endosymbiont, Wolbachia, in its filarial host.![]()
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Affiliation(s)
- Christina A Bulman
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA, USA
| | - Laura Chappell
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, CA, USA
| | - Emma Gunderson
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA, USA
| | - Ian Vogel
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA, USA
| | - Brenda Beerntsen
- Veterinary Pathobiology, University of Missouri-Columbia, Columbia, MO, USA
| | - Barton E Slatko
- Molecular Parasitology Division, New England Biolabs Inc, Ipswich, MA, USA
| | - William Sullivan
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, CA, USA
| | - Judy A Sakanari
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA, USA.
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Wan Sulaiman WA, Kamtchum-Tatuene J, Mohamed MH, Ramachandran V, Ching SM, Sazlly Lim SM, Hashim HZ, Inche Mat LN, Hoo FK, Basri H. Anti- Wolbachia therapy for onchocerciasis & lymphatic filariasis: Current perspectives. Indian J Med Res 2020; 149:706-714. [PMID: 31496523 PMCID: PMC6755775 DOI: 10.4103/ijmr.ijmr_454_17] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Onchocerciasis and lymphatic filariasis (LF) are human filarial diseases belonging to the group of neglected tropical diseases, leading to permanent and long-term disability in infected individuals in the endemic countries such as Africa and India. Microfilaricidal drugs such as ivermectin and albendazole have been used as the standard therapy in filariasis, although their efficacy in eliminating the diseases is not fully established. Anti-Wolbachia therapy employs antibiotics and is a promising approach showing potent macrofilaricidal activity and also prevents embryogenesis. This has translated to clinical benefits resulting in successful eradication of microfilarial burden, thus averting the risk of adverse events from target species as well as those due to co-infection with loiasis. Doxycycline shows potential as an anti-Wolbachia treatment, leading to the death of adult parasitic worms. It is readily available, cheap and safe to use in adult non-pregnant patients. Besides doxycycline, several other potential antibiotics are also being investigated for the treatment of LF and onchocerciasis. This review aims to discuss and summarise recent developments in the use of anti-Wolbachia drugs to treat onchocerciasis and LF.
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Affiliation(s)
- Wan Aliaa Wan Sulaiman
- Department of Medicine, Faculty of Medicine & Health Sciences; Laboratory of Medical Gerontology, Malaysian Research Institute on Ageing, Universiti Putra Malaysia, Serdang, Malaysia
| | - Joseph Kamtchum-Tatuene
- Liverpool Brain Infection Group, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | - Mohd Hazmi Mohamed
- Department of Surgery, Faculty of Medicine & Health Sciences; Laboratory of Medical Gerontology, Malaysian Research Institute on Ageing, Universiti Putra Malaysia, Serdang, Malaysia
| | - Vasudevan Ramachandran
- Laboratory of Medical Gerontology, Malaysian Research Institute on Ageing, Universiti Putra Malaysia, Serdang, Malaysia
| | - Siew Mooi Ching
- Department of Family Medicine, Faculty of Medicine & Health Sciences, Universiti Putra Malaysia, Serdang, Malaysia
| | - Sazlyna Mohd Sazlly Lim
- Department of Medicine, Faculty of Medicine & Health Sciences, Malaysian Research Institute on Ageing, Universiti Putra Malaysia, Serdang, Malaysia
| | - Hasnur Zaman Hashim
- Department of Medicine, Faculty of Medicine & Health Sciences, Malaysian Research Institute on Ageing, Universiti Putra Malaysia, Serdang, Malaysia
| | - Liyana Najwa Inche Mat
- Department of Medicine, Faculty of Medicine & Health Sciences; Laboratory of Medical Gerontology, Malaysian Research Institute on Ageing, Universiti Putra Malaysia, Serdang, Malaysia
| | - Fan Kee Hoo
- Department of Medicine, Faculty of Medicine & Health Sciences, Malaysian Research Institute on Ageing, Universiti Putra Malaysia, Serdang, Malaysia
| | - Hamidon Basri
- Department of Medicine, Faculty of Medicine & Health Sciences; Laboratory of Medical Gerontology, Malaysian Research Institute on Ageing, Universiti Putra Malaysia, Serdang, Malaysia
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11
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Short-course quinazoline drug treatments are effective in the Litomosoides sigmodontis and Brugia pahangi jird models. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2019; 12:18-27. [PMID: 31869759 PMCID: PMC6931063 DOI: 10.1016/j.ijpddr.2019.12.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 11/30/2019] [Accepted: 12/02/2019] [Indexed: 12/26/2022]
Abstract
The quinazolines CBR417 and CBR490 were previously shown to be potent anti-wolbachials that deplete Wolbachia endosymbionts of filarial nematodes and present promising pre-clinical candidates for human filarial diseases such as onchocerciasis. In the present study we tested both candidates in two models of chronic filarial infection, namely the Litomosoides sigmodontis and Brugia pahangi jird model and assessed their long-term effect on Wolbachia depletion, microfilariae counts and filarial embryogenesis 16−18 weeks after treatment initiation (wpt). Once per day (QD) oral treatment with CBR417 (50 mg/kg) for 4 days or twice per day (BID) with CBR490 (25 mg/kg) for 7 days during patent L. sigmodontis infection reduced the Wolbachia load by >99% and completely cleared peripheral microfilaremia from 10–14 wpt. Similarly, 7 days of QD treatments (40 mg/kg) with CBR417 or CBR490 cleared >99% of Wolbachia from B. pahangi and reduced peritoneal microfilariae counts by 93% in the case of CBR417 treatment. Transmission electron microscopy analysis indicated intensive damage to the B. pahangi ovaries following CBR417 treatment and in accordance filarial embryogenesis was inhibited in both models after CBR417 or CBR490 treatment. Suboptimal treatment regimens of CBR417 or CBR490 did not lead to a maintained reduction of the microfilariae and Wolbachia load. In conclusion, CBR417 or CBR490 are pre-clinical candidates for filarial diseases, which achieve long-term clearance of Wolbachia endosymbionts of filarial nematodes, inhibit filarial embryogenesis and clear microfilaremia with treatments as short as 7 days. CBR417 and CBR490 provide long-term effects in 2 chronic filaria jird models. CBR417 and CBR490 deplete >99% Wolbachia in B. pahangi and L. sigmodontis filariae. CBR417 and CBR490 clear L. sigmodontis microfilariae after 10–14 weeks. CBR417 and CBR490 inhibit filarial embryogenesis in both models. Suboptimal doses do not maintain reduction of microfilariae and Wolbachia.
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12
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Wanji S, Nji TM, Hamill L, Dean L, Ozano K, Njouendou AJ, Abong RA, Obie ED, Amuam A, Ekanya R, Ndongmo WPC, Ndzeshang BL, Fung EG, Nnamdi DB, Nkimbeng DA, Teghen S, Kah E, Piotrowski H, Forrer A, Khan JAM, Woode ME, Niessen L, Watson V, Njoumemi Z, Murdoch ME, Thomson R, Theobald S, Enyong P, Turner JD, Taylor MJ. Implementation of test-and-treat with doxycycline and temephos ground larviciding as alternative strategies for accelerating onchocerciasis elimination in an area of loiasis co-endemicity: the COUNTDOWN consortium multi-disciplinary study protocol. Parasit Vectors 2019; 12:574. [PMID: 31801631 PMCID: PMC6894124 DOI: 10.1186/s13071-019-3826-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 11/25/2019] [Indexed: 12/15/2022] Open
Abstract
Background Onchocerciasis is a priority neglected tropical disease targeted for elimination by 2025. The standard strategy to combat onchocerciasis is annual Community-Directed Treatment with ivermectin (CDTi). Yet, high prevalence rates and transmission persist following > 12 rounds in South-West Cameroon. Challenges include programme coverage, adherence to, and acceptability of ivermectin in an area of Loa loa co-endemicity. Loiasis patients harbouring heavy infections are at risk of potentially fatal serious adverse events following CDTi. Alternative strategies are therefore needed to achieve onchocerciasis elimination where CDTi effectiveness is suboptimal. Methods/design We designed an implementation study to evaluate integrating World Health Organisation-endorsed alternative strategies for the elimination of onchocerciasis, namely test-and-treat with the macrofilaricide, doxycycline (TTd), and ground larviciding for suppression of blackfly vectors with the organophosphate temephos. A community-based controlled before-after intervention study will be conducted among > 2000 participants in 20 intervention (Meme River Basin) and 10 control (Indian River Basin) communities. The primary outcome measure is O. volvulus prevalence at follow-up 18-months post-treatment. The study involves four inter-disciplinary components: parasitology, entomology, applied social sciences and health economics. Onchocerciasis skin infection will be diagnosed by skin biopsy and Loa loa infection will be diagnosed by parasitological examination of finger-prick blood samples. A simultaneous clinical skin disease assessment will be made. Eligible skin-snip-positive individuals will be offered directly-observed treatment for 5 weeks with 100 mg/day doxycycline. Transmission assessments of onchocerciasis in the communities will be collected post-human landing catch of the local biting blackfly vector prior to ground larviciding with temephos every week (0.3 l/m3) until biting rate falls below 5/person/day. Qualitative research, including in-depth interviews and focus-group discussions will be used to assess acceptability and feasibility of the implemented alternative strategies among intervention recipients and providers. Health economics will assess the cost-effectiveness of the implemented interventions. Conclusions Using a multidisciplinary approach, we aim to assess the effectiveness of TTd, alone or in combination with ground larviciding, following a single intervention round and scrutinise the acceptability and feasibility of implementing at scale in similar hotspots of onchocerciasis infection, to accelerate onchocerciasis elimination.
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Affiliation(s)
- Samuel Wanji
- COUNTDOWN, Department of Microbiology and Parasitology, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon. .,COUNTDOWN, Research Foundation for Tropical Diseases and Environment, P.O. Box 474, Buea, Cameroon.
| | - Theobald Mue Nji
- COUNTDOWN, Research Foundation for Tropical Diseases and Environment, P.O. Box 474, Buea, Cameroon.,COUNTDOWN, Department of Sociology and Anthropology, Faculty of Social and Management Sciences, University of Buea, P.O. Box 63, Buea, Cameroon
| | | | - Laura Dean
- COUNTDOWN, Department of International Public Health, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK
| | - Kim Ozano
- COUNTDOWN, Department of International Public Health, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK
| | - Abdel J Njouendou
- COUNTDOWN, Research Foundation for Tropical Diseases and Environment, P.O. Box 474, Buea, Cameroon.,COUNTDOWN, Department of Biomedical Sciences, Faculty of Health Sciences, University of Buea, P.O. Box 12, Buea, Cameroon
| | - Raphael A Abong
- COUNTDOWN, Department of Microbiology and Parasitology, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon.,COUNTDOWN, Research Foundation for Tropical Diseases and Environment, P.O. Box 474, Buea, Cameroon
| | - Elisabeth Dibando Obie
- COUNTDOWN, Department of Microbiology and Parasitology, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon.,COUNTDOWN, Research Foundation for Tropical Diseases and Environment, P.O. Box 474, Buea, Cameroon
| | - Andrew Amuam
- COUNTDOWN, Department of Microbiology and Parasitology, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon.,COUNTDOWN, Research Foundation for Tropical Diseases and Environment, P.O. Box 474, Buea, Cameroon
| | - Relindis Ekanya
- COUNTDOWN, Department of Microbiology and Parasitology, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon.,COUNTDOWN, Research Foundation for Tropical Diseases and Environment, P.O. Box 474, Buea, Cameroon
| | - Winston Patrick Chounna Ndongmo
- COUNTDOWN, Department of Microbiology and Parasitology, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon.,COUNTDOWN, Research Foundation for Tropical Diseases and Environment, P.O. Box 474, Buea, Cameroon
| | - Bertrand L Ndzeshang
- COUNTDOWN, Department of Microbiology and Parasitology, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon.,COUNTDOWN, Research Foundation for Tropical Diseases and Environment, P.O. Box 474, Buea, Cameroon
| | - Ebua Gallus Fung
- COUNTDOWN, Research Foundation for Tropical Diseases and Environment, P.O. Box 474, Buea, Cameroon.,COUNTDOWN, Department of Sociology and Anthropology, Faculty of Social and Management Sciences, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Dum-Buo Nnamdi
- COUNTDOWN, Research Foundation for Tropical Diseases and Environment, P.O. Box 474, Buea, Cameroon.,COUNTDOWN, Department of Sociology and Anthropology, Faculty of Social and Management Sciences, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Desmond Akumtoh Nkimbeng
- COUNTDOWN, Department of Microbiology and Parasitology, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon.,COUNTDOWN, Research Foundation for Tropical Diseases and Environment, P.O. Box 474, Buea, Cameroon
| | - Samuel Teghen
- COUNTDOWN, Department of Microbiology and Parasitology, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon.,COUNTDOWN, Research Foundation for Tropical Diseases and Environment, P.O. Box 474, Buea, Cameroon
| | - Emmanuel Kah
- COUNTDOWN, Department of Microbiology and Parasitology, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon.,COUNTDOWN, Research Foundation for Tropical Diseases and Environment, P.O. Box 474, Buea, Cameroon
| | - Helen Piotrowski
- COUNTDOWN, Department of International Public Health, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK
| | - Armelle Forrer
- COUNTDOWN, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK
| | - Jahangir A M Khan
- COUNTDOWN, Department of Clinical Sciences, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK
| | - Maame E Woode
- Centre for Health Economics, Monash University, Victoria, Australia
| | - Louis Niessen
- COUNTDOWN, Department of International Public Health, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK.,Department of International Health, Johns Hopkins School of Public Health, Baltimore, USA
| | - Victoria Watson
- COUNTDOWN, Department of Clinical Sciences, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK
| | - Zakariaou Njoumemi
- Health Economics Unit, Department of Public Health, Faculty of Medicine and Biomedical Sciences, University of Yaounde I, P.O. Box 1364, Yaounde, Cameroon
| | - Michele E Murdoch
- COUNTDOWN, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK.,West Herts Hospitals NHS Trust, Watford General Hospital, Vicarage Road, Watford, UK
| | - Rachael Thomson
- COUNTDOWN, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK
| | - Sally Theobald
- COUNTDOWN, Department of International Public Health, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK
| | - Peter Enyong
- COUNTDOWN, Department of Microbiology and Parasitology, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon.,COUNTDOWN, Research Foundation for Tropical Diseases and Environment, P.O. Box 474, Buea, Cameroon
| | - Joseph D Turner
- COUNTDOWN, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK.
| | - Mark J Taylor
- COUNTDOWN, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK
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Cafarelli C, Russo G, Mathis A, Silaghi C. De novo genome sequencing and comparative stage-specific transcriptomic analysis of Dirofilaria repens. Int J Parasitol 2019; 49:911-919. [PMID: 31557466 DOI: 10.1016/j.ijpara.2019.04.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 04/16/2019] [Accepted: 04/24/2019] [Indexed: 01/26/2023]
Abstract
The zoonotic mosquito-borne filarial nematode Dirofilaria repens causes subcutaneous and ocular infections in dogs, cats and humans. From infected vertebrate hosts, microfilariae are taken up by mosquitoes and develop into infective L3. These are transmitted to new vertebrate hosts and develop over two further moults to adult worms. The aims of the project were (i) the de novo sequencing and annotation of the D. repens genome and (ii) comparative transcriptomic analyses of the two developmental stages, mf and L3. Genomic DNA was obtained from adult male D. repens. RNA was extracted from mf from naturally infected dogs and from L3 produced in Aedes aegypti mosquitoes fed on blood spiked with mf. The 99.59 MB genome was approximately 17% larger than that of the related species Dirofilaria immitis (dog heartworm) and contained 8.9% fewer predicted genes (10,357). Approximately 1.8% of identified proteins (206/11,262) could not be mapped to D. immitis. Out of these, six (2.9%) presented an ortholog in all other considered filarial nematodes (e.g. Loa loa) and Caenorhabditis elegans. A significantly higher number of D. repens proteins, compared with D. immitis, mapped to the filarial nematode L. loa, reflecting the similarity in biology of D. repens and L. loa. A total of 876 genes were differentially expressed, of which 591 could be annotated in UniProtKB/Swiss-Prot. In particular, 155 genes with a UniProtKB/Swiss-Prot annotation to C. elegans and filarial nematodes were upregulated in the L3 and 57 in the mf stage, respectively. Fifteen Gene Ontology Biological Processes were significantly enriched for the L3 group and 12 for the mf. To our knowledge these data provide the first insight into the differential gene expression profiles of this filarial nematode and can serve future investigations of metabolic processes and stage-specific diagnostics.
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Affiliation(s)
- Chiara Cafarelli
- National Centre for Vector Entomology, Institute of Parasitology, Vetsuisse Faculty, University of Zürich, Winterthurerstr 266a, 8057 Zürich, Switzerland
| | - Giancarlo Russo
- Functional Genomics Center Zürich, University of Zürich and ETH Zürich, Winterthurerstr. 190, 8057 Zürich, Switzerland
| | - Alexander Mathis
- National Centre for Vector Entomology, Institute of Parasitology, Vetsuisse Faculty, University of Zürich, Winterthurerstr 266a, 8057 Zürich, Switzerland
| | - Cornelia Silaghi
- National Centre for Vector Entomology, Institute of Parasitology, Vetsuisse Faculty, University of Zürich, Winterthurerstr 266a, 8057 Zürich, Switzerland; Friedrich-Loeffler-Institute, Federal Research Institute for Animal Health, Südufer 10, 17493 Greifswald, Insel Riems, Germany.
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14
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Whittaker C, Walker M, Pion SD, Chesnais CB, Boussinesq M, Basáñez MG. The Population Biology and Transmission Dynamics of Loa loa. Trends Parasitol 2018; 34:335-350. [DOI: 10.1016/j.pt.2017.12.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 12/10/2017] [Accepted: 12/11/2017] [Indexed: 11/27/2022]
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Abstract
Mansonellosis is a filarial disease caused by three species of filarial (nematode) parasites (Mansonella perstans, Mansonella streptocerca, and Mansonella ozzardi) that use humans as their main definitive hosts. These parasites are transmitted from person to person by bloodsucking females from two families of flies (Diptera). Biting midges (Ceratopogonidae) transmit all three species of Mansonella, but blackflies (Simuliidae) are also known to play a role in the transmission of M. ozzardi in parts of Latin America. M. perstans and M. streptocerca are endemic in western, eastern, and central Africa, and M. perstans is also present in the neotropical region from equatorial Brazil to the Caribbean coast. M. ozzardi has a patchy distribution in Latin America and the Caribbean. Mansonellosis infections are thought to have little pathogenicity and to be almost always asymptomatic, but occasionally causing itching, joint pains, enlarged lymph glands, and vague abdominal symptoms. In Brazil, M. ozzardi infections are also associated with corneal lesions. Diagnosis is usually performed by detecting microfilariae in peripheral blood or skin without any periodicity. There is no standard treatment at present for mansonellosis. The combination therapy of diethylcarbamazine plus mebendazole for M. perstans microfilaremia is presently one of the most widely used, but the use of ivermectin has also been proven to be very effective against microfilariae. Recently, doxycycline has shown excellent efficacy and safety when used as an antimicrobial against endosymbiotic Wolbachia bacteria harbored by some strains of M. perstans and M. ozzardi. Diethylcarbamazine and ivermectin have been used effectively to treat M. streptocerca infection. There are at present no estimates of the disease burden caused by mansonellosis, and thus its importance to many global health professionals and policy makers is presently limited to how it can interfere with diagnostic tools used in modern filarial disease control and elimination programs aimed at other species of filariae.
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Affiliation(s)
- Thuy-Huong Ta-Tang
- Malaria and Emerging Parasitic Diseases Laboratory, National Microbiology Center, Instituto de Salud Carlos III, Majadahonda, Spain,
| | - James L Crainey
- Laboratory of Infectious Disease Ecology in the Amazon, Oswaldo Cruz Foundation, Instituto Leônidas e Maria Deane, Manaus, Brazil
| | - Rory J Post
- School of Natural Sciences and Psychology, John Moores University, Liverpool
- Department of Disease Control, Faculty of Infectious Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Sergio Lb Luz
- Laboratory of Infectious Disease Ecology in the Amazon, Oswaldo Cruz Foundation, Instituto Leônidas e Maria Deane, Manaus, Brazil
| | - José M Rubio
- Malaria and Emerging Parasitic Diseases Laboratory, National Microbiology Center, Instituto de Salud Carlos III, Majadahonda, Spain,
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Albendazole and antibiotics synergize to deliver short-course anti- Wolbachia curative treatments in preclinical models of filariasis. Proc Natl Acad Sci U S A 2017; 114:E9712-E9721. [PMID: 29078351 PMCID: PMC5692564 DOI: 10.1073/pnas.1710845114] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Filarial nematode infections, caused by Wuchereria bancrofti, Brugia malayi (elephantiasis), and Onchocerca volvulus (river blindness) infect 150 million of the world’s poorest populations and cause profound disability. Standard treatments require repetitive, long-term, mass drug administrations and have failed to interrupted transmission in certain sub-Saharan African regions. A drug cure using doxycycline, which targets the essential filarial endosymbiont Wolbachia, is clinically effective but programmatically challenging to implement due to long treatment durations and contraindications. Here we provide proof-of-concept of a radical improvement of targeting Wolbachia via identification of drug synergy between the anthelmintic albendazole and antibiotics. This synergy enables the shortening of treatment duration of macrofilaricidal anti-Wolbachia based treatments from 4 wk to 7 d with registered drugs ready for clinical testing. Elimination of filariasis requires a macrofilaricide treatment that can be delivered within a 7-day period. Here we have identified a synergy between the anthelmintic albendazole (ABZ) and drugs depleting the filarial endosymbiont Wolbachia, a proven macrofilaricide target, which reduces treatment from several weeks to 7 days in preclinical models. ABZ had negligible effects on Wolbachia but synergized with minocycline or rifampicin (RIF) to deplete symbionts, block embryogenesis, and stop microfilariae production. Greater than 99% Wolbachia depletion following 7-day combination of RIF+ABZ also led to accelerated macrofilaricidal activity. Thus, we provide preclinical proof-of-concept of treatment shortening using antibiotic+ABZ combinations to deliver anti-Wolbachia sterilizing and macrofilaricidal effects. Our data are of immediate public health importance as RIF+ABZ are registered drugs and thus immediately implementable to deliver a 1-wk macrofilaricide. They also suggest that novel, more potent anti-Wolbachia drugs under development may be capable of delivering further treatment shortening, to days rather than weeks, if combined with benzimidazoles.
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Globisch D, Eubanks LM, Shirey RJ, Pfarr KM, Wanji S, Debrah AY, Hoerauf A, Janda KD. Validation of onchocerciasis biomarker N-acetyltyramine-O-glucuronide (NATOG). Bioorg Med Chem Lett 2017; 27:3436-3440. [PMID: 28600214 PMCID: PMC5510726 DOI: 10.1016/j.bmcl.2017.05.082] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 05/25/2017] [Accepted: 05/26/2017] [Indexed: 12/14/2022]
Abstract
The Neglected Tropical Disease onchocerciasis is a parasitic disease. Despite many control programmes by the World Health Organization (WHO), large communities in West and Central Africa are still affected. Besides logistic challenges during biannual mass drug administration, the lack of a robust, point-of-care diagnostic is limiting successful eradication of onchocerciasis. Towards the implementation of a non-invasive and point-of-care diagnostic, we have recently reported the discovery of the biomarker N-acetyltyramine-O-glucuronide (NATOG) in human urine samples using a metabolomics-mining approach. NATOG's biomarker value was enhanced during an investigation in a rodent model. Herein, we further detail the specificity of NATOG in active onchocerciasis infections as well as the co-infecting parasites Loa loa and Mansonella perstans. Our results measured by liquid chromatography coupled with mass spectrometry (LC-MS) reveal elevated NATOG values in mono- and co-infection samples only in the presence of the nematode Onchocerca volvulus. Metabolic pathway investigation of l-tyrosine/tyramine in all investigated nematodes uncovered an important link between the endosymbiotic bacterium Wolbachia and O. volvulus for the biosynthesis of NATOG. Based on these extended studies, we suggest NATOG as a biomarker for tracking active onchocerciasis infections and provide a threshold concentration value of NATOG for future diagnostic tool development.
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Affiliation(s)
- Daniel Globisch
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, United States; Department of Immunology, The Skaggs Institute for Chemical Biology, The Worm Institute of Research and Medicine (WIRM), The Scripps Research Institute, 10550 North Torrey, La Jolla, CA 92037, United States.
| | - Lisa M Eubanks
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, United States; Department of Immunology, The Skaggs Institute for Chemical Biology, The Worm Institute of Research and Medicine (WIRM), The Scripps Research Institute, 10550 North Torrey, La Jolla, CA 92037, United States
| | - Ryan J Shirey
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, United States; Department of Immunology, The Skaggs Institute for Chemical Biology, The Worm Institute of Research and Medicine (WIRM), The Scripps Research Institute, 10550 North Torrey, La Jolla, CA 92037, United States
| | - Kenneth M Pfarr
- Institute of Medical Microbiology, Immunology, and Parasitology (IMMIP), University Hospital Bonn, Sigmund Freud Straße 25, 53105 Bonn, Germany
| | - Samuel Wanji
- Research Foundation in Tropical Diseases and Environment (REFOTDE), P.O Box 474, Buea, Cameroon
| | - Alexander Y Debrah
- Faculty of Allied Health Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana; Kumasi Centre for Collaborative Research in Tropical Medicine (KCCR), Kumasi, Ghana
| | - Achim Hoerauf
- Institute of Medical Microbiology, Immunology, and Parasitology (IMMIP), University Hospital Bonn, Sigmund Freud Straße 25, 53105 Bonn, Germany
| | - Kim D Janda
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, United States; Department of Immunology, The Skaggs Institute for Chemical Biology, The Worm Institute of Research and Medicine (WIRM), The Scripps Research Institute, 10550 North Torrey, La Jolla, CA 92037, United States
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18
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Herrick JA, Legrand F, Gounoue R, Nchinda G, Montavon C, Bopda J, Tchana SM, Ondigui BE, Nguluwe K, Fay MP, Makiya M, Metenou S, Nutman TB, Kamgno J, Klion AD. Posttreatment Reactions After Single-Dose Diethylcarbamazine or Ivermectin in Subjects With Loa loa Infection. Clin Infect Dis 2017; 64:1017-1025. [PMID: 28329346 DOI: 10.1093/cid/cix016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 01/15/2017] [Indexed: 12/17/2022] Open
Abstract
Background Severe adverse reactions have been observed in individuals with Loa loa infection treated with either diethylcarbamazine (DEC), the drug of choice for loiasis, or ivermectin (IVM), which is used in mass drug administration programs for control of onchocerciasis and lymphatic filariasis in Africa. In this study, posttreatment clinical and immunologic reactions were compared following single-dose therapy with DEC or IVM to assess whether these reactions have the same underlying pathophysiology. Methods Twelve patients with loiasis and microfilarial counts <2000 mf/mL were randomized to receive single-dose DEC (8 mg/kg) or IVM (200 µg/kg). Clinical and laboratory assessments were performed at 4, 8, 24, 48, and 72 hours and 5, 7, 9, and 14 days posttreatment. Results Posttreatment adverse events were similar following DEC or IVM, but peaked earlier in subjects who received DEC, consistent with a trend toward more rapid and complete microfilarial clearance in the DEC group. After a transient rise (post-IVM) or fall (post-DEC) in the first 24 hours posttreatment, the eosinophil count rose significantly in both groups, peaking at day 5 in the DEC group and day 9 in the IVM group. Serum interleukin 5 levels and eosinophil activation, as assessed by surface expression of CD69 and serum levels of eosinophil granule proteins, were increased posttreatment in both groups. Conclusions Despite differences in eosinophil and lymphocyte counts during the first 24 hours posttreatment, the overall pattern of hematologic and immunologic changes suggest that posttreatment reactions following DEC and IVM share a common pathophysiology. Clinical Trials Registration NCT01593722.
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Affiliation(s)
- Jesica A Herrick
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Fanny Legrand
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | | | - Godwin Nchinda
- Laboratory of Immunology, Chantal Biya International Reference Centre for Research on Prevention and Management of HIV/AIDS, Yaoundé, Cameroon
| | - Céline Montavon
- Institut de recherche pour le développement, Montpellier, France
| | - Jean Bopda
- Center for Research on Filariasis and Other Tropical Diseases, Yaoundé, Cameroon
| | | | | | | | - Michael P Fay
- Biostatistics Research Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Michelle Makiya
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Simon Metenou
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Thomas B Nutman
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Joseph Kamgno
- Center for Research on Filariasis and Other Tropical Diseases, Yaoundé, Cameroon.,Faculty of Medicine and Biomedical Sciences, University of Yaoundé I, Cameroon
| | - Amy D Klion
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
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19
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Aljayyoussi G, Tyrer HE, Ford L, Sjoberg H, Pionnier N, Waterhouse D, Davies J, Gamble J, Metuge H, Cook DAN, Steven A, Sharma R, Guimaraes AF, Clare RH, Cassidy A, Johnston KL, Myhill L, Hayward L, Wanji S, Turner JD, Taylor MJ, Ward SA. Short-Course, High-Dose Rifampicin Achieves Wolbachia Depletion Predictive of Curative Outcomes in Preclinical Models of Lymphatic Filariasis and Onchocerciasis. Sci Rep 2017; 7:210. [PMID: 28303006 PMCID: PMC5428297 DOI: 10.1038/s41598-017-00322-5] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 02/21/2017] [Indexed: 12/29/2022] Open
Abstract
Lymphatic filariasis (LF) and onchocerciasis are priority neglected tropical diseases targeted for elimination. The only safe drug treatment with substantial curative activity against the filarial nematodes responsible for LF (Brugia malayi, Wuchereria bancrofti) or onchocerciasis (Onchocerca volvulus) is doxycycline. The target of doxycycline is the essential endosymbiont, Wolbachia. Four to six weeks doxycycline therapy achieves >90% depletion of Wolbachia in worm tissues leading to blockade of embryogenesis, adult sterility and premature death 18-24 months post-treatment. Long treatment length and contraindications in children and pregnancy are obstacles to implementing doxycycline as a public health strategy. Here we determine, via preclinical infection models of Brugia malayi or Onchocerca ochengi that elevated exposures of orally-administered rifampicin can lead to Wolbachia depletions from filariae more rapidly than those achieved by doxycycline. Dose escalation of rifampicin achieves >90% Wolbachia depletion in time periods of 7 days in B. malayi and 14 days in O. ochengi. Using pharmacokinetic-pharmacodynamic modelling and mouse-human bridging analysis, we conclude that clinically relevant dose elevations of rifampicin, which have recently been determined as safe in humans, could be administered as short courses to filariasis target populations with potential to reduce anti-Wolbachia curative therapy times to between one and two weeks.
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Affiliation(s)
- Ghaith Aljayyoussi
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Hayley E Tyrer
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Louise Ford
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Hanna Sjoberg
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Nicolas Pionnier
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - David Waterhouse
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Jill Davies
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Joanne Gamble
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Haelly Metuge
- Research Foundation in Tropical Medicine and the Environment, Buea, Cameroon
- Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
| | - Darren A N Cook
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Andrew Steven
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Raman Sharma
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Ana F Guimaraes
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Rachel H Clare
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Andrew Cassidy
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Kelly L Johnston
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Laura Myhill
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Laura Hayward
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Samuel Wanji
- Research Foundation in Tropical Medicine and the Environment, Buea, Cameroon
- Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
| | - Joseph D Turner
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Mark J Taylor
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.
| | - Stephen A Ward
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
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20
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Hise AG, Gillette-Ferguson I, Pearlman E. Immunopathogenesis of Onchocerca volvulus keratitis (river blindness): a novel role for TLR4 and endosymbiotic Wolbachia bacteria. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/09680519030090060101] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Infection with the parasitic nematode Onchocerca volvulus is associated with inflammation of the skin and cornea that can lead to blindness. Corneal damage is thought to occur as a result of the host inflammatory responses to degenerating microfilariae in the eye. We have utilized a murine model of corneal inflammation (keratitis) to investigate the immune and inflammatory responses associated with river blindness. Soluble extracts of O. volvulus, a filarial species that contains the endosymbiont bacteria Wolbachia or Acanthocheilonema viteae (a nematode not naturally infected with the bacteria) were injected into mouse corneas. Inflammatory responses and corneal changes were measured. We demonstrated a major role for endosymbiont Wolbachia bacteria and Toll-like receptor 4 (TLR4) in the pathogenesis of ocular onchocerciasis.
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Affiliation(s)
- Amy G. Hise
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, Ohio, USA
| | | | - Eric Pearlman
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, Ohio, USA,
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21
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Keroack CD, Wurster JI, Decker CG, Williams KM, Slatko BE, Foster JM, Williams SA. Absence of the Filarial Endosymbiont Wolbachia in Seal Heartworm (Acanthocheilonema spirocauda) but Evidence of Ancient Lateral Gene Transfer. J Parasitol 2016; 102:312-8. [PMID: 26859724 DOI: 10.1645/15-872] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The symbiotic relationship of Wolbachia spp. was first observed in insects and subsequently in many parasitic filarial nematodes. This bacterium is believed to provide metabolic and developmental assistance to filarial parasitic nematodes, although the exact nature of this relationship remains to be fully elucidated. While Wolbachia is present in most filarial nematodes in the family Onchocercidae, it is absent in several disparate species such as the human parasite Loa loa . All tested members of the genus Acanthocheilonema, such as Acanthocheilonema viteae, have been shown to lack Wolbachia. Consistent with this, we show that Wolbachia is absent from the seal heartworm (Acanthocheilonema spirocauda), but lateral gene transfer (LGT) of DNA sequences between Wolbachia and A. spirocauda has occurred, indicating a past evolutionary association. Seal heartworm is an important pathogen of phocid seals and understanding its basic biology is essential for conservation of the host. The findings presented here may allow for the development of future treatments or diagnostics for the disease and also aid in clarification of the complicated nematode-Wolbachia relationship.
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Affiliation(s)
- Caroline D Keroack
- * Smith College, Department of Biological Sciences, Northampton, Massachusetts 01063
| | - Jenna I Wurster
- * Smith College, Department of Biological Sciences, Northampton, Massachusetts 01063
| | - Caroline G Decker
- * Smith College, Department of Biological Sciences, Northampton, Massachusetts 01063
| | - Kalani M Williams
- * Smith College, Department of Biological Sciences, Northampton, Massachusetts 01063
| | | | | | - Steven A Williams
- * Smith College, Department of Biological Sciences, Northampton, Massachusetts 01063
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22
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Johnston KL, Ford L, Umareddy I, Townson S, Specht S, Pfarr K, Hoerauf A, Altmeyer R, Taylor MJ. Repurposing of approved drugs from the human pharmacopoeia to target Wolbachia endosymbionts of onchocerciasis and lymphatic filariasis. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2014; 4:278-86. [PMID: 25516838 PMCID: PMC4266796 DOI: 10.1016/j.ijpddr.2014.09.001] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
There is an urgent need to discover a macrofilaricide for filariasis. The A·WOL approach is to target the Wolbachia bacteria of filarial nematodes. The human pharmacopoeia was screened against Wolbachia for potential repurposing. 69 orally available hits from different drug categories were identified in vitro. In vivo, the tetracyclines, fluoroquinolones and rifamycins were the most active.
Lymphatic filariasis and onchocerciasis are debilitating diseases caused by parasitic filarial nematodes infecting around 150 million people throughout the tropics with more than 1.5 billion at risk. As with other neglected tropical diseases, classical drug-discovery and development is lacking and a 50 year programme of macrofilaricidal discovery failed to deliver a drug which can be used as a public health tool. Recently, antibiotic targeting of filarial Wolbachia, an essential bacterial symbiont, has provided a novel drug treatment for filariasis with macrofilaricidal activity, although the current gold-standard, doxycycline, is unsuitable for use in mass drug administration (MDA). The anti-Wolbachia (A·WOL) Consortium aims to identify novel anti-Wolbachia drugs, compounds or combinations that are suitable for use in MDA. Development of a Wolbachia cell-based assay has enabled the screening of the approved human drug-pharmacopoeia (∼2600 drugs) for a potential repurposing. This screening strategy has revealed that approved drugs from various classes show significant bacterial load reduction equal to or superior to the gold-standard doxycycline, with 69 orally available hits from different drug categories being identified. Based on our defined hit criteria, 15 compounds were then selectively screened in a Litomosoides sigmodontis mouse model, 4 of which were active. These came from the tetracycline, fluoroquinolone and rifamycin classes. This strategy of repurposing approved drugs is a promising development in the goal of finding a novel treatment against filariasis and could also be a strategy applicable for other neglected tropical diseases.
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Affiliation(s)
- Kelly L Johnston
- Filariasis Research Group, Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Louise Ford
- Filariasis Research Group, Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Indira Umareddy
- CombinatoRx-Singapore Ptd Ltd, 11 Biopolis Way, 138667 Singapore, Singapore
| | - Simon Townson
- Tropical Parasitic Diseases Unit, Northwick Park Institute for Medical Research, Watford Road, Harrow, Middlesex HA1 3UJ, UK
| | - Sabine Specht
- Institute of Medical Microbiology, Immunology & Parasitology, University Hospital of Bonn, Sigmund Freud Strasse 25, 53105 Bonn, Germany
| | - Kenneth Pfarr
- Institute of Medical Microbiology, Immunology & Parasitology, University Hospital of Bonn, Sigmund Freud Strasse 25, 53105 Bonn, Germany
| | - Achim Hoerauf
- Institute of Medical Microbiology, Immunology & Parasitology, University Hospital of Bonn, Sigmund Freud Strasse 25, 53105 Bonn, Germany
| | - Ralf Altmeyer
- CombinatoRx-Singapore Ptd Ltd, 11 Biopolis Way, 138667 Singapore, Singapore ; Institut Pasteur Shanghai, Chinese Academy of Sciences, 320 Yueyang Road, 200031 Shanghai, People's Republic of China
| | - Mark J Taylor
- Filariasis Research Group, Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
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23
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Tallon LJ, Liu X, Bennuru S, Chibucos MC, Godinez A, Ott S, Zhao X, Sadzewicz L, Fraser CM, Nutman TB, Dunning Hotopp JC. Single molecule sequencing and genome assembly of a clinical specimen of Loa loa, the causative agent of loiasis. BMC Genomics 2014; 15:788. [PMID: 25217238 PMCID: PMC4175631 DOI: 10.1186/1471-2164-15-788] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Accepted: 09/02/2014] [Indexed: 12/31/2022] Open
Abstract
Background More than 20% of the world’s population is at risk for infection by filarial nematodes and >180 million people worldwide are already infected. Along with infection comes significant morbidity that has a socioeconomic impact. The eight filarial nematodes that infect humans are Wuchereria bancrofti, Brugia malayi, Brugia timori, Onchocerca volvulus, Loa loa, Mansonella perstans, Mansonella streptocerca, and Mansonella ozzardi, of which three have published draft genome sequences. Since all have humans as the definitive host, standard avenues of research that rely on culturing and genetics have often not been possible. Therefore, genome sequencing provides an important window into understanding the biology of these parasites. The need for large amounts of high quality genomic DNA from homozygous, inbred lines; the availability of only short sequence reads from next-generation sequencing platforms at a reasonable expense; and the lack of random large insert libraries has limited our ability to generate high quality genome sequences for these parasites. However, the Pacific Biosciences single molecule, real-time sequencing platform holds great promise in reducing input amounts and generating sufficiently long sequences that bypass the need for large insert paired libraries. Results Here, we report on efforts to generate a more complete genome assembly for L. loa using genetically heterogeneous DNA isolated from a single clinical sample and sequenced on the Pacific Biosciences platform. To obtain the best assembly, numerous assemblers and sequencing datasets were analyzed, combined, and compared. Quiver-informed trimming of an assembly of only Pacific Biosciences reads by HGAP2 was selected as the final assembly of 96.4 Mbp in 2,250 contigs. This results in ~9% more of the genome in ~85% fewer contigs from ~80% less starting material at a fraction of the cost of previous Roche 454-based sequencing efforts. Conclusions The result is the most complete filarial nematode assembly produced thus far and demonstrates the utility of single molecule sequencing on the Pacific Biosciences platform for genetically heterogeneous metazoan genomes. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-788) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Julie C Dunning Hotopp
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA.
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24
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Slatko BE, Luck AN, Dobson SL, Foster JM. Wolbachia endosymbionts and human disease control. Mol Biochem Parasitol 2014; 195:88-95. [DOI: 10.1016/j.molbiopara.2014.07.004] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2014] [Revised: 07/09/2014] [Accepted: 07/10/2014] [Indexed: 01/08/2023]
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25
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Gehringer C, Kreidenweiss A, Flamen A, Antony JS, Grobusch MP, Bélard S. Molecular Evidence ofWolbachiaEndosymbiosis inMansonella perstansin Gabon, Central Africa. J Infect Dis 2014; 210:1633-8. [DOI: 10.1093/infdis/jiu320] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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26
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Koutsovoulos G, Makepeace B, Tanya VN, Blaxter M. Palaeosymbiosis revealed by genomic fossils of Wolbachia in a strongyloidean nematode. PLoS Genet 2014; 10:e1004397. [PMID: 24901418 PMCID: PMC4046930 DOI: 10.1371/journal.pgen.1004397] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2014] [Accepted: 04/06/2014] [Indexed: 12/19/2022] Open
Abstract
Wolbachia are common endosymbionts of terrestrial arthropods, and are also found in nematodes: the animal-parasitic filaria, and the plant-parasite Radopholus similis. Lateral transfer of Wolbachia DNA to the host genome is common. We generated a draft genome sequence for the strongyloidean nematode parasite Dictyocaulus viviparus, the cattle lungworm. In the assembly, we identified nearly 1 Mb of sequence with similarity to Wolbachia. The fragments were unlikely to derive from a live Wolbachia infection: most were short, and the genes were disabled through inactivating mutations. Many fragments were co-assembled with definitively nematode-derived sequence. We found limited evidence of expression of the Wolbachia-derived genes. The D. viviparus Wolbachia genes were most similar to filarial strains and strains from the host-promiscuous clade F. We conclude that D. viviparus was infected by Wolbachia in the past, and that clade F-like symbionts may have been the source of filarial Wolbachia infections. Bovine lungworms are economically important nematode parasites of cattle. We have sequenced the genome of the bovine lungworm to provide information for drug and vaccine discovery. Within the lungworm genome we found extensive evidence of an ancient association between the lungworm and a bacterium called Wolbachia. The lungworm Wolbachia is now a “fossil” in the genome, but tells of an ancient infection. Association between lungworms, and related nematode worms, and Wolbachia was not known previously. We have used the lungworm Wolbachia sequence to explore the history of nematode-Wolbachia interactions, particularly the jumping of these symbionts between arthropods and nematodes.
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Affiliation(s)
- Georgios Koutsovoulos
- Institute of Evolutionary Biology, The University of Edinburgh, Edinburgh, United Kingdom
- * E-mail:
| | - Benjamin Makepeace
- Institute of Infection and Global Health, The University of Liverpool, Liverpool, United Kingdom
| | - Vincent N. Tanya
- Institut de Recherche Agricole pour le Développement, Regional Centre of Wakwa, Ngaoundéré, Adamawa Region, Cameroon
| | - Mark Blaxter
- Institute of Evolutionary Biology, The University of Edinburgh, Edinburgh, United Kingdom
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27
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Metzger WG, Mordmüller B. Loa loa—does it deserve to be neglected? THE LANCET. INFECTIOUS DISEASES 2014; 14:353-7. [DOI: 10.1016/s1473-3099(13)70263-9] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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28
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Foster JM, Landmann F, Ford L, Johnston KL, Elsasser SC, Schulte-Hostedde AI, Taylor MJ, Slatko BE. Absence of Wolbachia endobacteria in the human parasitic nematode Dracunculus medinensis and two related Dracunculus species infecting wildlife. Parasit Vectors 2014; 7:140. [PMID: 24685011 PMCID: PMC3994231 DOI: 10.1186/1756-3305-7-140] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Accepted: 03/20/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Wolbachia endosymbionts are a proven target for control of human disease caused by filarial nematodes. However, little is known about the occurrence of Wolbachia in taxa closely related to the superfamily Filarioidea. Our study addressed the status of Wolbachia presence in members of the superfamily Dracunculoidea by screening the human parasite Dracunculus medinensis and related species from wildlife for Wolbachia. FINDINGS D. medinensis, D. lutrae and D. insignis specimens were all negative for Wolbachia colonization by PCR screening for the Wolbachia ftsZ, 16S rRNA and Wolbachia surface protein (wsp) sequences. The quality and purity of the DNA preparations was confirmed by amplification of nematode 18S rRNA and cytochrome c oxidase subunit I sequences. Furthermore, Wolbachia endobacteria were not detected by whole mount fluorescence staining, or by immunohistochemistry using a Wolbachia-specific antiserum. In contrast, positive control Brugia malayi worms were shown to harbour Wolbachia by PCR, fluorescence staining and immunohistochemistry. CONCLUSIONS Three examined species of Dracunculus showed no evidence of Wolbachia endobacteria. This supports that members of the superfamily Dracunculoidea are free of Wolbachia. Within the order Spirurida, these endosymbionts appear restricted to the Filarioidea.
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Affiliation(s)
- Jeremy M Foster
- Parasitology Division, New England Biolabs, 240 County Road, Ipswich, MA 01938, USA.
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Abstract
Two of the major filarial infections, lymphatic filariasis (LF) and onchocerciasis, affect 150 million people, while 1 billion living in endemic areas are at risk of infection. Public health programs to control these infections have successfully existed for years and have evolved from activities driven by the WHO into global programs with public-private partnerships. Currently, these programs use yearly mass application of drugs that mainly kill the larval stages (the microfilariae), with the aim of preventing uptake by the transmitting insect vectors and thus, to block transmission and reduce the infections to such levels that in 15-30 years from now, they will no longer pose a public health problem. While the programs have been very successful in general, there are drawbacks such as coverage being too low within the population, reappearance of infection by migration of infected people into controlled areas, targeting of a stage (the microfilaria) that does not induce pathology in LF and thus lowers compliance, and the potential development of drug resistance, first indications of which have been clearly observed in onchocerciasis. In addition, even without drawbacks, program scopes are not the eradication of filarial infections, which is, however, an ultimate goal of control activities. There is therefore an unequivocal call for the development of higher efficient, complementary chemotherapeutical approaches that lead to a long-lasting reduction of the pathology-inducing worm stages; that is, microfilariae in onchocerciasis and adult worms in LF, or to a macrofilaricidal effect. The recent discovery that depletion of Wolbachia endosymbionts by tetracycline antibiotics leads to long-lasting sterility of adult female worms in onchocerciasis and a macrofilaricidal effect in LF fulfils these requirements. Successful regimens have already been published and agreed upon for use by expert panels. While these regimens are still too long for mass application, the antiwolbachial chemotherapy can currently be applied in the form of a suitable doxycycline regimen for 6 weeks for the treatment of individuals, and exploited in the future for the development of new drugs suitable for mass application. In addition, first data suggest that Wolbachia may also be major mediators of lymphangiogenesis and that their depletion is associated with reduction of lymph vessel-specific vascular endothelial growth factors and reduced lymph vessel size.
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Affiliation(s)
- Achim Hoerauf
- Institute of Medical Microbiology, Immunology and Parasitology, University Clinic Bonn, 53105 Bonn, Germany.
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Babayan SA, Allen JE, Taylor DW. Future prospects and challenges of vaccines against filariasis. Parasite Immunol 2012; 34:243-53. [PMID: 22150082 DOI: 10.1111/j.1365-3024.2011.01350.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Filarial infections remain a major public health and socio-economic problem across the tropics, despite considerable effort to reduce disease burden or regionally eliminate the infection with mass drug administration programmes. The sustainability of these programmes is now open to question owing to a range of issues, not least of which is emerging evidence for drug resistance. Vaccination, if developed appropriately, remains the most cost-effective means of long-term disease control. The rationale for the feasibility of vaccination against filarial parasites including onchocerciasis (river blindness, Onchocerca volvulus) and lymphatic filariasis (Wuchereria bancrofti or Brugia malayi) is founded on evidence from both humans and animal models for the development of protective immunity. Nonetheless, enormous challenges need to be faced in terms of overcoming parasite-induced suppression without inducing pathology as well as the need to both recognize and tackle evolutionary and ecological obstacles to successful vaccine development. Nonetheless, new technological advances in addition to systems biology approaches offer hope that optimal immune responses can be induced that will prevent infection, disease and/or transmission.
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Affiliation(s)
- Simon A Babayan
- Institute of Immunology and Infection Research, and Centre for Immunity, Infection & Evolution, University of Edinburgh, Edinburgh, UK.
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McNulty SN, Mullin AS, Vaughan JA, Tkach VV, Weil GJ, Fischer PU. Comparing the mitochondrial genomes of Wolbachia-dependent and independent filarial nematode species. BMC Genomics 2012; 13:145. [PMID: 22530989 PMCID: PMC3409033 DOI: 10.1186/1471-2164-13-145] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Accepted: 04/24/2012] [Indexed: 11/25/2022] Open
Abstract
Background Many species of filarial nematodes depend on Wolbachia endobacteria to carry out their life cycle. Other species are naturally Wolbachia-free. The biological mechanisms underpinning Wolbachia-dependence and independence in filarial nematodes are not known. Previous studies have indicated that Wolbachia have an impact on mitochondrial gene expression, which may suggest a role in energy metabolism. If Wolbachia can supplement host energy metabolism, reduced mitochondrial function in infected filarial species may account for Wolbachia-dependence. Wolbachia also have a strong influence on mitochondrial evolution due to vertical co-transmission. This could drive alterations in mitochondrial genome sequence in infected species. Comparisons between the mitochondrial genome sequences of Wolbachia-dependent and independent filarial worms may reveal differences indicative of altered mitochondrial function. Results The mitochondrial genomes of 5 species of filarial nematodes, Acanthocheilonema viteae, Chandlerella quiscali, Loa loa, Onchocerca flexuosa, and Wuchereria bancrofti, were sequenced, annotated and compared with available mitochondrial genome sequences from Brugia malayi, Dirofilaria immitis, Onchocerca volvulus and Setaria digitata. B. malayi, D. immitis, O. volvulus and W. bancrofti are Wolbachia-dependent while A. viteae, C. quiscali, L. loa, O. flexuosa and S. digitata are Wolbachia-free. The 9 mitochondrial genomes were similar in size and AT content and encoded the same 12 protein-coding genes, 22 tRNAs and 2 rRNAs. Synteny was perfectly preserved in all species except C. quiscali, which had a different order for 5 tRNA genes. Protein-coding genes were expressed at the RNA level in all examined species. In phylogenetic trees based on mitochondrial protein-coding sequences, species did not cluster according to Wolbachia dependence. Conclusions Thus far, no discernable differences were detected between the mitochondrial genome sequences of Wolbachia-dependent and independent species. Additional research will be needed to determine whether mitochondria from Wolbachia-dependent filarial species show reduced function in comparison to the mitochondria of Wolbachia-independent species despite their sequence-level similarities.
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Affiliation(s)
- Samantha N McNulty
- Infectious Diseases Division, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA.
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McNulty SN, Fischer K, Mehus JO, Vaughan JA, Tkach VV, Weil GJ, Fischer PU. Absence of Wolbachia endobacteria in Chandlerella quiscali, an avian filarial parasite. J Parasitol 2011; 98:382-7. [PMID: 22032328 DOI: 10.1645/ge-2879.1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Chandlerella quiscali is a filarial nematode parasite of the common grackle (Quiscalus quiscula), a widespread bird species found throughout most of North America. Worms collected from wild-caught birds were morphologically identified as C. quiscali and tested for the presence of Wolbachia, an alphaproteobacterial endosymbiont required for reproduction and maturation by many filarial species. Although various methods, including polymerase chain reaction, in situ hybridization, and immunohistology, were used, we were unable to detect evidence of colonization with Wolbachia. Due to the widespread distribution of the grackle host, localization within the host, and high prevalence, C. quiscali may be among the most easily obtainable of Wolbachia-free filarial species. Further studies of C. quiscali and other Wolbachia-free filarial species may help to clarify the reason(s) that some filarial species require Wolbachia but others do not.
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Affiliation(s)
- Samantha N McNulty
- Infectious Diseases Division, Department of Internal Medicine, Washington University School of Medicine, Campus Box 8051, 660 S. Euclid Avenue, St. Louis, Missouri 63110, USA.
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Interaction of a Wolbachia WSP-like protein with a nuclear-encoded protein of Brugia malayi. Int J Parasitol 2011; 41:1053-61. [PMID: 21782817 DOI: 10.1016/j.ijpara.2011.05.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2011] [Revised: 05/21/2011] [Accepted: 05/23/2011] [Indexed: 11/23/2022]
Abstract
The Brugia malayi endosymbiont Wolbachia has recently been shown to be essential for its host's survival and development. However, relatively little is known about Wolbachia proteins that interact with the filarial host and which might be important in maintaining the obligate symbiotic relationship. The Wolbachia surface proteins (WSPs) are members of the outer membrane protein family and we hypothesise that they might be involved in the Wolbachia-Brugia symbiotic relationship. Notably, immunolocalisation studies of two WSP members, WSP-0432 and WSP-0284 in B. malayi female adult worms showed that the corresponding proteins are not only present on the surface of Wolbachia but also in the host tissues, with WSP-0284 more abundant in the cuticle, hypodermis and the nuclei within the embryos. These results confirmed that WSPs might be secreted by Wolbachia into the worm's tissue. Our present studies focus on the potential involvement of WSP-0284 in the symbiotic relationship of Wolbachia with its filarial host. We show that WSP-0284 binds specifically to B. malayi crude protein extracts. Furthermore, a fragment of the hypothetical B. malayi protein (Bm1_46455) was found to bind WSP-0284 by panning of a B. malayi cDNA library. The interaction of WSP-0284 and this protein was further confirmed by ELISA and pull-down assays. Localisation by immunoelectron microscopy within Wolbachia cells as well as in the worm's tissues, cuticle and nuclei within embryos established that both proteins are present in similar locations within the parasite and the bacteria. Identifying such specific interactions between B. malayi and Wolbachia proteins should lead to a better understanding of the molecular basis of the filarial nematode and Wolbachia symbiosis.
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Belanger DH, Perkins SL. Wolbachia infection and mitochondrial diversity in the canine heartworm (Dirofilaria immitis). ACTA ACUST UNITED AC 2011; 21:227-33. [PMID: 21171866 DOI: 10.3109/19401736.2010.533765] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND AND AIMS Many species of filarial nematodes are infected with Wolbachia pipientis, a maternally inherited endosymbiont. In addition to manipulating host reproduction, these bacteria also affect the evolution of the mitochondrial DNA with which they are transmitted. Selective sweeps can establish a single mitochondrial lineage within a Wolbachia-infected population and purge genetic diversity. While this phenomenon has been studied in insect model systems, it has not been thoroughly examined in a filarial nematode. MATERIALS AND METHODS Patterns of mitochondrial diversity were examined in Dirofilaria immitis, a Wolbachia-infected species. RESULTS The levels of genetic diversity observed in canine heartworm were much lower than those in related species not known to be hosts of Wolbachia. CONCLUSION RESULTS suggest that a maternally inherited endosymbiont can depress mitochondrial diversity in a filarial host.
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Affiliation(s)
- Diana H Belanger
- Sackler Institute for Comparative Genomics, American Museum of Natural History, New York, NY 10024, USA.
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36
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Chai JY. Recent Advances in the Use of Anthelmintics for Treating Nematode Infections. Infect Chemother 2011. [DOI: 10.3947/ic.2011.43.1.26] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Jong-Yil Chai
- Department of Parasitology and Tropical Medicine, Seoul National University College of Medicine, Seoul, Korea
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Abstract
Lymphatic filariasis and onchocerciasis are parasitic helminth diseases that constitute a serious public health issue in tropical regions. The filarial nematodes that cause these diseases are transmitted by blood-feeding insects and produce chronic and long-term infection through suppression of host immunity. Disease pathogenesis is linked to host inflammation invoked by the death of the parasite, causing hydrocoele, lymphoedema, and elephantiasis in lymphatic filariasis, and skin disease and blindness in onchocerciasis. Most filarial species that infect people co-exist in mutualistic symbiosis with Wolbachia bacteria, which are essential for growth, development, and survival of their nematode hosts. These endosymbionts contribute to inflammatory disease pathogenesis and are a target for doxycycline therapy, which delivers macrofilaricidal activity, improves pathological outcomes, and is effective as monotherapy. Drugs to treat filariasis include diethylcarbamazine, ivermectin, and albendazole, which are used mostly in combination to reduce microfilariae in blood (lymphatic filariasis) and skin (onchocerciasis). Global programmes for control and elimination have been developed to provide sustained delivery of drugs to affected communities to interrupt transmission of disease and ultimately eliminate this burden on public health.
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Affiliation(s)
- Mark J Taylor
- Liverpool School of Tropical Medicine, Liverpool, UK.
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McNulty SN, Foster JM, Mitreva M, Dunning Hotopp JC, Martin J, Fischer K, Wu B, Davis PJ, Kumar S, Brattig NW, Slatko BE, Weil GJ, Fischer PU. Endosymbiont DNA in endobacteria-free filarial nematodes indicates ancient horizontal genetic transfer. PLoS One 2010; 5:e11029. [PMID: 20543958 PMCID: PMC2882956 DOI: 10.1371/journal.pone.0011029] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2010] [Accepted: 05/19/2010] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Wolbachia are among the most abundant symbiotic microbes on earth; they are present in about 66% of all insect species, some spiders, mites and crustaceans, and most filarial nematode species. Infected filarial nematodes, including many pathogens of medical and veterinary importance, depend on Wolbachia for proper development and survival. The mechanisms behind this interdependence are not understood. Interestingly, a minority of filarial species examined to date are naturally Wolbachia-free. METHODOLOGY/PRINCIPAL FINDINGS We used 454 pyrosequencing to survey the genomes of two distantly related Wolbachia-free filarial species, Acanthocheilonema viteae and Onchocerca flexuosa. This screen identified 49 Wolbachia-like DNA sequences in A. viteae and 114 in O. flexuosa. qRT-PCR reactions detected expression of 30 Wolbachia-like sequences in A. viteae and 56 in O. flexuosa. Approximately half of these appear to be transcribed from pseudogenes. In situ hybridization showed that two of these pseudogene transcripts were specifically expressed in developing embryos and testes of both species. CONCLUSIONS/SIGNIFICANCE These results strongly suggest that the last common ancestor of extant filarial nematodes was infected with Wolbachia and that this former endosymbiont contributed to their genome evolution. Horizontally transferred Wolbachia DNA may explain the ability of some filarial species to live and reproduce without the endosymbiont while other species cannot.
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Affiliation(s)
- Samantha N. McNulty
- Infectious Diseases Division, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Jeremy M. Foster
- New England Biolabs, Ipswich, Massachusetts, United States of America
| | - Makedonka Mitreva
- The Genome Center, Department of Genetics, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Julie C. Dunning Hotopp
- Institute for Genome Sciences, Department of Microbiology and Immunology, University of Maryland Baltimore, Baltimore, Maryland, United States of America
| | - John Martin
- The Genome Center, Department of Genetics, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Kerstin Fischer
- Infectious Diseases Division, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Bo Wu
- New England Biolabs, Ipswich, Massachusetts, United States of America
| | - Paul J. Davis
- New England Biolabs, Ipswich, Massachusetts, United States of America
| | - Sanjay Kumar
- New England Biolabs, Ipswich, Massachusetts, United States of America
| | | | - Barton E. Slatko
- New England Biolabs, Ipswich, Massachusetts, United States of America
| | - Gary J. Weil
- Infectious Diseases Division, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Peter U. Fischer
- Infectious Diseases Division, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
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Figueredo-Silva J, Cavalcanti C, Montenegro LT, Norões J, Dreyer G. Diethylcarbamazine and non-diethylcarbamazine related bancroftian granuloma: an immunohistochemical study of eosinophil toxic proteins. INTERNATIONAL JOURNAL OF BIOMEDICAL SCIENCE : IJBS 2010; 6:111-9. [PMID: 23675184 PMCID: PMC3614742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Accepted: 04/27/2010] [Indexed: 11/03/2022]
Abstract
It has been suggested, mostly using in vitro experiments, that defenses against parasites involve mainly activated eosinophils and their toxic proteins, such as major basic protein (MBP), eosinophil cationic protein (ECP) and eosinophil peroxidase (EPO). Eosinophil degranulation has been described around degenerating onchocercal microfilariae in patients treated with diethylcarbamazine (DEC). In bancroftian filariasis, traditional histopathologic studies have shown remarkable numbers of eosinophils in granulomatous lesions associated with both DEC-induced and spontaneous death of adult Wuchereria bancrofti parasites. No immunohistochemical study targeting eosinophil degranulation has been previously performed in these granulomas, which are found mainly within intrascrotal lymphatic vessels. This investigation was undertaken in 22 (12 DEC-treated and 10 untreated) male patients in order to determine the immunohistochemical expressions of MBP, EPO and ECP in bancofitian granulomas, using the indirect method. Stained intact esosinophils, as well as granular, extra-cellular material positive for all three proteins, were found in all granulomas. The immunohistochemical patterns were similar in both DEC-treated and untreated cases, irrespective of microfilaremia, blood eosinophilia, and granuloma age. Positive intact cells were observed mostly at the periphery of the granulomas, whereas granular material predominated in central areas around dead or degenerating parasites. These results indicate that eosinophils accumulate in the granulomas and degranulate preferentially in close proximity to degenerating or dead adult parasites. In bancroftian granulomas, influx and degranulation of eosinophils are considered a consequence of parasite death, rather than its cause.
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Affiliation(s)
- Jose Figueredo-Silva
- Núcleo de Ensino e Pesquisa em Patologia, Faculdade de Ciências Médicas, Universidade Estadual do Piauí, Piauí, Brazil;
| | - Carmelita Cavalcanti
- Laboratório de Imunopatologia Keizo Asami (LIKA), Universidade Federal de Pernambuco, Pernambuco, Brazil;
| | - Luciano Tavares Montenegro
- Departamento de Patologia, Centro de Ciências da Saúde, Universidade Federal de Pernambuco, Pernambuco, Brazil;
| | - Joaquim Norões
- Serviço de Urologia, Departamento de Cirurgia, Centro de Ciências da Saúde, Universidade Federal de Pernambuco, Pernambuco, Brazil;,Núcleo de Ensino Pesquisa e Assistência em Filariose (NEPAF), Hospital das Clínicas, Universidade Federal de Pernambuco, Pernambuco, Brazil;
| | - Gerusa Dreyer
- Núcleo de Ensino Pesquisa e Assistência em Filariose (NEPAF), Hospital das Clínicas, Universidade Federal de Pernambuco, Pernambuco, Brazil;,Centro de Pesquisas Aggeu Magalhães (CPqAM), Fundação Oswaldo Cruz (FIOCRUZ), Pernambuco, Brazil;,NGO Amaury Coutinho Rua Conselheiro Portela, 665, Sala 120, Espinheiro, Recife, 50670-900, Pernambuco, Brazil
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Turner JD, Tendongfor N, Esum M, Johnston KL, Langley RS, Ford L, Faragher B, Specht S, Mand S, Hoerauf A, Enyong P, Wanji S, Taylor MJ. Macrofilaricidal activity after doxycycline only treatment of Onchocerca volvulus in an area of Loa loa co-endemicity: a randomized controlled trial. PLoS Negl Trop Dis 2010; 4:e660. [PMID: 20405054 PMCID: PMC2854122 DOI: 10.1371/journal.pntd.0000660] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Accepted: 03/04/2010] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND The risk of severe adverse events following treatment of onchocerciasis with ivermectin in areas co-endemic with loiasis currently compromises the development of control programmes and the treatment of co-infected individuals. We therefore assessed whether doxycycline treatment could be used without subsequent ivermectin administration to effectively deliver sustained effects on Onchocerca volvulus microfilaridermia and adult viability. Furthermore we assessed the safety of doxycycline treatment prior to ivermectin administration in a subset of onchocerciasis individuals co-infected with low to moderate intensities of Loa loa microfilaraemia. METHODS A double-blind, randomized, field trial was conducted of 6 weeks of doxycycline (200 mg/day) alone, doxycycline in combination with ivermectin (150 microg/kg) at +4 months or placebo matching doxycycline + ivermectin at +4 months in 150 individuals infected with Onchocerca volvulus. A further 22 individuals infected with O. volvulus and low to moderate intensities of Loa loa infection were administered with a course of 6 weeks doxycycline with ivermectin at +4 months. Treatment efficacy was determined at 4, 12 and 21 months after the start of doxycycline treatment together with the frequency and severity of adverse events. RESULTS One hundred and four (60.5%) participants completed all treatment allocations and follow up assessments over the 21-month trial period. At 12 months, doxycycline/ivermectin treated individuals had lower levels of microfilaridermia and higher frequency of amicrofilaridermia compared with ivermectin or doxycycline only groups. At 21 months, microfilaridermia in doxycycline/ivermectin and doxycycline only groups was significantly reduced compared to the ivermectin only group. 89% of the doxycycline/ivermectin group and 67% of the doxycycline only group were amicrofilaridermic, compared with 21% in the ivermectin only group. O. volvulus from doxycycline groups were depleted of Wolbachia and all embryonic stages in utero. Notably, the viability of female adult worms was significantly reduced in doxycycline treated groups and the macrofilaricidal and sterilising activity was unaffected by the addition of ivermectin. Treatment with doxycycline was well tolerated and the incidence of adverse event to doxycycline or ivermectin did not significantly deviate between treatment groups. CONCLUSIONS A six-week course of doxycycline delivers macrofilaricidal and sterilizing activities, which is not dependent upon co-administration of ivermectin. Doxycycline is well tolerated in patients co-infected with moderate intensities of L. loa microfilariae. Therefore, further trials are warranted to assess the safety and efficacy of doxycycline-based interventions to treat onchocerciasis in individuals at risk of serious adverse reactions to standard treatments due to the co-occurrence of high intensities of L. loa parasitaemias. The development of an anti-wolbachial treatment regime compatible with MDA control programmes could offer an alternative to the control of onchocerciasis in areas of co-endemicity with loiasis and at risk of severe adverse reactions to ivermectin. TRIAL REGISTRATION Controlled-Trials.com ISRCTN48118452.
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Affiliation(s)
- Joseph D. Turner
- Filariasis Research Laboratory, Molecular and Biochemical Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Nicholas Tendongfor
- Department of Life Sciences, Faculty of Science, University of Buea, Buea, Cameroon
- Research Foundation in Tropical Diseases and Environment (REFOTDE), Buea, Cameroon
| | - Mathias Esum
- Department of Life Sciences, Faculty of Science, University of Buea, Buea, Cameroon
- Research Foundation in Tropical Diseases and Environment (REFOTDE), Buea, Cameroon
| | - Kelly L. Johnston
- Filariasis Research Laboratory, Molecular and Biochemical Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - R. Stuart Langley
- Filariasis Research Laboratory, Molecular and Biochemical Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Louise Ford
- Filariasis Research Laboratory, Molecular and Biochemical Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Brian Faragher
- Filariasis Research Laboratory, Molecular and Biochemical Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Sabine Specht
- Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Bonn, Germany
| | - Sabine Mand
- Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Bonn, Germany
| | - Achim Hoerauf
- Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Bonn, Germany
| | - Peter Enyong
- Tropical Medicine Research Station, Kumba, Cameroon
| | - Samuel Wanji
- Department of Life Sciences, Faculty of Science, University of Buea, Buea, Cameroon
- Research Foundation in Tropical Diseases and Environment (REFOTDE), Buea, Cameroon
| | - Mark J. Taylor
- Filariasis Research Laboratory, Molecular and Biochemical Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- * E-mail:
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Abstract
Filariasis is caused by thread-like nematode worms, classified according to their presence in the vertebrate host. The cutaneous group includes Onchocerca volvulus, Loa loa and Mansonella streptocerca; the lymphatic group includes Wuchereria bancrofti, Brugia malayi and Brugia timori and the body cavity group includes Mansonella perstans and Mansonella ozzardi. Lymphatic filariasis, a mosquito-borne disease, is one of the most prevalent diseases in tropical and subtropical countries and is accompanied by a number of pathological conditions. In recent years, there has been rapid progress in filariasis research, which has provided new insights into the pathogenesis of filarial disease, diagnosis, chemotherapy, the host–parasite relationship and the genomics of the parasite. Together, these insights are assisting the identification of novel drug targets and the discovery of antifilarial agents and candidate vaccine molecules. This review discusses the antifilarial activity of various chemical entities, the merits and demerits of antifilarial drugs currently in use, their mechanisms of action, in addition to antifilarial drug targets and their validation.
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Abstract
Among the causes of lymphoedema (LE), secondary LE due to filariasis is the most prevalent. It affects only a minority of the 120 million people infected with the causative organisms of lymphatic filariasis (LF), Wuchereria bancrofti and Brugia malayi/timori, but is clustered in families, indicating a genetic basis for development of this pathology. The majority of infected individuals develop filarial-specific immunosuppression that starts even before birth in cases where mothers are infected and is characterized by regulatory T-cell responses and high levels of IgG4, thus tolerating high parasite loads and microfilaraemia. In contrast, individuals with this pathology show stronger immune reactions biased towards Th1, Th2 and probably also Th17. Importantly, as for the aberrant lymph vessel development, innate immune responses that are triggered by the filarial antigen ultimately result in the activation of vascular endothelial growth factors (VEGF), thus promoting lymph vessel hyperplasia as a first step to lymphoedema development. Wolbachia endosymbionts are major inducers of these responses in vitro, and their depletion by doxycycline in LF patients reduces plasma VEGF and soluble VEGF-receptor-3 levels to those seen in endemic normals preceding pathology improvement. The search for the immunogenetic basis for LE could lead to the identification of risk factors and thus, to prevention; and has so far led to the identification of single-nucleotide polymorphisms (SNP) with potential functional relevance to VEGF, cytokine and toll-like receptor (TLR) genes. Hydrocele, a pathology with some similarity to LE in which both lymph vessel dilation and lymph extravasation are shared sequelae, has been found to be strongly associated with a VEGF-A SNP known for upregulation of this (lymph-)angiogenesis factor.
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Affiliation(s)
- K M Pfarr
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
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44
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Paily KP, Hoti SL, Das PK. A review of the complexity of biology of lymphatic filarial parasites. J Parasit Dis 2009; 33:3-12. [PMID: 23129882 PMCID: PMC3454129 DOI: 10.1007/s12639-009-0005-4] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2009] [Accepted: 12/01/2009] [Indexed: 10/19/2022] Open
Abstract
There are about five more common, including Wuchereria bancrofti and Brugia malayi, and four less common filarial parasites infecting human. Genetic analysis of W. bancrofti populations in India showed that two strains of the species are prevalent in the country. The adult filarial parasites are tissue specific in the human host and their embryonic stage, called microfilariae (mf), are found in the blood or skin of the host, depending upon the species of the parasite. Three genetically determined physiological races exist in W. bancrofti and B. malayi, based on the microfilarial periodicity. They are the nocturnally periodic, nocturnally subperiodic and diurnally subperiodic forms. The susceptibility of a mosquito species to filarial infection depends on various factors, which could be genetic, physiological or physical. Survival analysis of Culex quinquefasciatus infected with W. bancrofti showed that the parasite load in the mosquito is a risk factor of vector survival. The extrinsic life cycle of the parasite is initiated when the mf are ingested by a mosquito vector during feeding on the host blood. On maturity, most of the infective L3 stage larvae migrate to the head and proboscis of the mosquito to get transmitted to the mammalian host during subsequent feeding. They develop to the adult L5 stage and the period of development and the longevity of the parasites varies according to the species of the nematode and the mammalian host. The rate of production of mf by the adult female was found to be stable at least for a period of five years. The life span of the mf has some influence on the dynamics of transmission of filariasis. Recent studies show that the endosymbiont, Wolbachia, plays an important role in the survival of filarial parasites. The possibility of in vitro and in vivo culture of filarial parasites is also reviewed.
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Affiliation(s)
- K. P. Paily
- Vector Control Research Centre (Indian Council of Medical Research), Indira Nagar, Pondicherry, 605 006 India
| | - S. L. Hoti
- Vector Control Research Centre (Indian Council of Medical Research), Indira Nagar, Pondicherry, 605 006 India
| | - P. K. Das
- Vector Control Research Centre (Indian Council of Medical Research), Indira Nagar, Pondicherry, 605 006 India
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Coulibaly YI, Dembele B, Diallo AA, Lipner EM, Doumbia SS, Coulibaly SY, Konate S, Diallo DA, Yalcouye D, Kubofcik J, Doumbo OK, Traore AK, Keita AD, Fay MP, Traore SF, Nutman TB, Klion AD. A randomized trial of doxycycline for Mansonella perstans infection. N Engl J Med 2009; 361:1448-58. [PMID: 19812401 PMCID: PMC3410935 DOI: 10.1056/nejmoa0900863] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Mansonella perstans infection is common in areas of Africa where Wuchereria bancrofti, a causative agent of lymphatic filariasis, is endemic. M. perstans is refractory to standard antifilarial therapies. The recent discovery of bacterial endosymbionts (e.g., wolbachia) in most filarial species, including M. perstans, provides new therapeutic options for reducing microfilaremia. METHODS In an open-label, randomized trial, we recruited subjects with M. perstans microfilaremia, with or without concomitant W. bancrofti infection, from four villages in Mali and randomly assigned them to receive doxycycline, at a dose of 200 mg daily for 6 weeks (106 subjects), or no treatment (110). At 6 months, subjects who were coinfected with W. bancrofti underwent a second random assignment, to treatment with a single dose of albendazole (400 mg) and ivermectin (150 microg per kilogram of body weight) or no treatment. Subjects were monitored daily during the first 6-week study period for adverse events. M. perstans and W. bancrofti microfilarial levels were assessed at 6, 12, and 36 months. RESULTS At 12 months, 67 of 69 subjects who had received treatment with doxycycline only (97%) had no detectable M. perstans microfilariae per 60 microl of blood, as compared with 10 of 63 subjects who had received no treatment (16%) (relative risk, 6.18; 95% confidence interval, 3.63 to 11.89; P<0.001). At 36 months, M. perstans microfilaremia remained suppressed in 48 of 64 subjects who had received treatment with doxycycline only (75%), a finding that was consistent with a macrofilaricidal effect of doxycycline. Vomiting was more frequent in the doxycycline-treated group than in the untreated group (17% vs. 4%). CONCLUSIONS These results are consistent with previous findings that M. perstans harbors the intracellular endosymbiont, wolbachia, and suggest that doxycycline is an effective therapy for M. perstans infection. (ClinicalTrials.gov number, NCT00340691.)
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Affiliation(s)
- Yaya I Coulibaly
- Faculty of Medicine, Pharmacy and Odontostomatology, University of Bamako, Bamako, Mali
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46
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Ghedin E, Hailemariam T, DePasse JV, Zhang X, Oksov Y, Unnasch TR, Lustigman S. Brugia malayi gene expression in response to the targeting of the Wolbachia endosymbiont by tetracycline treatment. PLoS Negl Trop Dis 2009; 3:e525. [PMID: 19806204 PMCID: PMC2754610 DOI: 10.1371/journal.pntd.0000525] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2009] [Accepted: 09/02/2009] [Indexed: 11/28/2022] Open
Abstract
Background Brugia malayi, like most human filarial parasite species, harbors an endosymbiotic bacterium of the genus Wolbachia. Elimination of the endosymbiont leads to sterilization of the adult female. Previous biochemical and genetic studies have established that communication with its endobacterium is essential for survival of the worm. Methodology/Principal findings We used electron microscopy to examine the effects of antibiotic treatment on Wolbachia cell structure. We have also used microarray and quantitative RT-PCR analyses to examine the regulation of the B. malayi transcripts altered in response to the anti-Wolbachia treatment. Microscopy of worms taken from animals treated with tetracycline for 14 and 21 days (14 d and 21 d) demonstrated substantial morphologic effects on the Wolbachia endobacterium by 14 d and complete degeneration of the endobacterial structures by 21 d. We observed upregulation of transcripts primarily encoding proteins involved in amino acid synthesis and protein translation, and downregulation of transcripts involved in cuticle biosynthesis after both 7 d and 14 d of treatment. In worms exposed to tetracycline in culture, substantial effects on endobacteria morphology were evident by day 3, and extensive death of the endobacteria was observed by day 5. In a detailed examination of the expression kinetics of selected signaling genes carried out on such cultured worms, a bimodal pattern of regulation was observed. The selected genes were upregulated during the early phase of antibiotic treatment and quickly downregulated in the following days. These same genes were upregulated once more at 6 days post-treatment. Conclusions/Significance Upregulation of protein translation and amino acid synthesis may indicate a generalized stress response induced in B. malayi due to a shortage of essential nutrients/factors that are otherwise supplied by Wolbachia. Downregulation of transcripts involved in cuticle biosynthesis perhaps reflects a disruption in the normal embryogenic program. This is confirmed by the expression pattern of transcripts that may be representative of the worms' response to Wolbachia in different tissues; the early peak potentially reflects the effect of bacteria death on the embryogenic program while the second peak may be a manifestation of the adult worm response to the affected bacteria within the hypodermis. Filarial parasites afflict hundreds of millions of individuals worldwide, and cause significant public health problems in many of the poorest countries in the world. Most of the human filarial parasite species, including Brugia malayi, harbor endosymbiotic bacteria of the genus Wolbachia. Elimination of the endosymbiont leads to sterilization of the adult female worm. The need exists for the development of new chemotherapeutic approaches that can practically exploit the vulnerability of the filaria to the loss of the Wolbachia. In this study we performed ultrastructural and microarray analyses of female worms collected from infected jirds treated with tetracycline. Results suggest that the endosymbiotic bacteria were specifically affected by the antibiotic. Furthermore, in response to the targeting of the endosymbiont, the parasites modulated expression of their genes. When exposed to tetracycline, the parasites over-expressed genes involved in protein synthesis. Expression of genes involved in cuticle biosynthesis and energy metabolism was, on the other hand, limited.
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Affiliation(s)
- Elodie Ghedin
- University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.
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47
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Wanji S, Tendongfor N, Nji T, Esum M, Che JN, Nkwescheu A, Alassa F, Kamnang G, Enyong PA, Taylor MJ, Hoerauf A, Taylor DW. Community-directed delivery of doxycycline for the treatment of onchocerciasis in areas of co-endemicity with loiasis in Cameroon. Parasit Vectors 2009; 2:39. [PMID: 19712455 PMCID: PMC2742514 DOI: 10.1186/1756-3305-2-39] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2009] [Accepted: 08/27/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Severe side effects following ivermectin treatment of onchocerciasis in areas of co-endemicity with loaisis have been an impediment for the work of the African Programme for Onchocerciasis Control (APOC) in forested regions of several countries. Doxycycline has been shown to be effective in the treatment of onchocerciasis and has the added advantages of killing adult Onchocerca volvulus but neither adult Loa loa nor their microfilariae. This drug therefore offers great potential for the treatment of onchocerciasis in areas of co-endemicity with loiasis. The limitation of use of this drug is the duration of treatment that may pose a potential problem with therapeutic coverage and compliance with treatment. To benefit from the advantages that doxycycline offers in the treatment of onchocerciasis, it will be necessary to establish an effective distribution system that can access remote communities. This study assessed the feasibility of a large-scale distribution of doxycycline for the treatment of onchocerciasis in areas of co-endemicity with loiasis using a community-directed approach. METHODS The study was carried out in 5 health areas co-endemic for Onchocerca volvulus and Loa loa which had no prior experience of the Community Directed Treatment with Ivermectin (CDTI). The community-directed delivery process was introduced using a cascade mechanism from the central health system that passed through the regional health delegation, health district and the health areas. Community health implementers (CHIs) were trained to deliver doxycycline to community members and, under the supervision of the health system, to monitor and document drug intake and side effects. RESULTS The community members adhered massively to the process. Of the 21355 individuals counted, 17519 were eligible for treatment and 12936 were treated with doxycycline; giving a therapeutic coverage of eligible population of 73.8%. Of the 12936 who started the treatment, 97.5% complied by the end of six weeks. No serious side effect was registered during the six week treatment. CONCLUSION This study indicates that when empowered the community health implementers can successfully deliver doxycycline for six weeks for the treatment of onchocerciasis in areas of co-endemicity with loiasis. The therapeutic coverage and the compliance treatment rate achieved in this study coupled to the known efficacy of doxycycline on O. volvulus, are indicators that the strategy involving the mass administration of doxycycline can be used to control onchocerciasis in those areas of co-endemicity with loiasis where ivermectin may be contraindicated.
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Affiliation(s)
- Samuel Wanji
- Department of Biochemistry and Microbiology, University of Buea, P,O, Box 63, Buea Cameroon.
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Foster JM, Kumar S, Ford L, Johnston KL, Ben R, Graeff-Teixeira C, Taylor MJ. Absence of Wolbachia endobacteria in the non-filariid nematodes Angiostrongylus cantonensis and A. costaricensis. Parasit Vectors 2008; 1:31. [PMID: 18801163 PMCID: PMC2565651 DOI: 10.1186/1756-3305-1-31] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2008] [Accepted: 09/18/2008] [Indexed: 11/10/2022] Open
Abstract
The majority of filarial nematodes harbour Wolbachia endobacteria, including the major pathogenic species in humans, Onchocerca volvulus, Brugia malayi and Wuchereria bancrofti. These obligate endosymbionts have never been demonstrated unequivocally in any non-filariid nematode. However, a recent report described the detection by PCR of Wolbachia in the metastrongylid nematode, Angiostrongylus cantonensis (rat lungworm), a leading cause of eosinophilic meningitis in humans. To address the intriguing possibility of Wolbachia infection in nematode species distinct from the Family Onchocercidae, we used both PCR and immunohistochemistry to screen samples of A. cantonensis and A. costaricensis for the presence of this endosymbiont. We were unable to detect Wolbachia in either species using these methodologies. In addition, bioinformatic and phylogenetic analyses of the Wolbachia gene sequences reported previously from A. cantonensis indicate that they most likely result from contamination with DNA from arthropods and filarial nematodes. This study demonstrates the need for caution in relying solely on PCR for identification of new endosymbiont strains from invertebrate DNA samples.
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Affiliation(s)
- Jeremy M Foster
- Molecular and Biochemical Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK.
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Keiser PB, Coulibaly Y, Kubofcik J, Diallo AA, Klion AD, Traoré SF, Nutman TB. Molecular identification of Wolbachia from the filarial nematode Mansonella perstans. Mol Biochem Parasitol 2008; 160:123-8. [PMID: 18538871 DOI: 10.1016/j.molbiopara.2008.04.012] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2008] [Revised: 04/23/2008] [Accepted: 04/24/2008] [Indexed: 11/29/2022]
Abstract
Wolbachiae are bacterial endosymbionts of insects and many filarial nematodes whose products trigger inflammation in filarial infections. The dependence of the parasites on their endosymbionts has also led to the use of antibiotics directed against the Wolbachiae, therapy that has been demonstrated to have a profound salutary effect on filarial infections. The identification of Wolbachiae in Mansonella species has been conclusively shown for Mansonella ozzardi (Mo), but not for Mansonella perstans (Mp). Using primers known to amplify the 16S ribosomal DNA of other filarial Wolbachiae, an identical 1393bp band was found in all samples tested. Sequence analysis of these samples demonstrated a single consensus sequence for Mp Wolbachia 16S rDNA that was most similar to Wolbachia sequences from other filarial nematodes. When aligned with the only other Mansonella Wolbachia sequence (Mo) there were only 8 nucleotide differences in the 1369bp overlapping sequence. Phylogenetic dendrograms, examining the relationship of the Mp Wolbachia to other Wolbachia 16S rDNA, showed that the Wolbachia tracked almost identically to the 5S rRNA of their parasite host. Wolbachia surface protein (WSP) was also demonstrated in protein extracted from Mp-containing whole blood. In advance of a treatment trial of Mp, a method for the quantitation of Mp Wolbachia was developed and used to demonstrate not only a relationship between microfilarial numbers and Wolbachia copy numbers, but also to demonstrate the effect of antibiotic on ridding Mp of Wolbachia.
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Affiliation(s)
- Paul B Keiser
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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Abstract
Loiasis affects millions of individuals living in the forest and savannah regions of Central Africa. In some areas, this disease constitutes one of the most common reasons for medical consultation. The burden posed by loiasis is probably under-estimated and, in addition, individuals harbouring high Loa microfilarial loads are at risk of developing serious neurological reactions after treatment with diethylcarbamazine or ivermectin. These events are currently significantly hampering the development of the African Programme for Onchocerciasis Control, and operational research is required to address the issue. The results of recent studies, involving either human populations from endemic areas or monkey models, have provided much more detail of the mechanisms associated with amicrofilaraemic or so-called 'occult' loiasis. New diagnostic tools have also been developed in the last decade, and various protocols are now available for the risk-free treatment of loiasis cases.
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Affiliation(s)
- M Boussinesq
- Institut de Recherche pour le Développement (IRD), UR024, Département Sociétés et Santé, 213 rue La Fayette, 75480 Paris Cedex 10, France.
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