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Weevil Carbohydrate Intake Triggers Endosymbiont Proliferation: A Trade-Off between Host Benefit and Endosymbiont Burden. mBio 2023; 14:e0333322. [PMID: 36779765 PMCID: PMC10127669 DOI: 10.1128/mbio.03333-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023] Open
Abstract
Nutritional symbioses between insects and intracellular bacteria (endosymbionts) are a major force of adaptation, allowing animals to colonize nutrient-poor ecological niches. Many beetles feeding on tyrosine-poor substrates rely on a surplus of aromatic amino acids produced by bacterial endosymbionts. This surplus of aromatic amino acids is crucial for the biosynthesis of a thick exoskeleton, the cuticle, which is made of a matrix of chitin with proteins and pigments built from tyrosine-derived molecules, providing an important defensive barrier against biotic and abiotic stress. Other endosymbiont-related advantages for beetles include faster development and improved fecundity. The association between Sitophilus oryzae and the Sodalis pierantonius endosymbiont represents a unique case study among beetles: endosymbionts undergo an exponential proliferation in young adults concomitant with the cuticle tanning, and then they are fully eliminated. While endosymbiont clearance, as well as total endosymbiont titer, are host-controlled processes, the mechanism triggering endosymbiont exponential proliferation remains poorly understood. Here, we show that endosymbiont exponential proliferation relies on host carbohydrate intake, unlike the total endosymbiont titer or the endosymbiont clearance, which are under host genetic control. Remarkably, insect fecundity was preserved, and the cuticle tanning was achieved, even when endosymbiont exponential proliferation was experimentally blocked, except in the context of a severely unbalanced diet. Moreover, a high endosymbiont titer coupled with nutrient shortage dramatically impacted host survival, revealing possible environment-dependent disadvantages for the host, likely due to the high energy cost of exponentially proliferating endosymbionts. IMPORTANCE Beetles thriving on tyrosine-poor diet sources often develop mutualistic associations with endosymbionts able to synthesize aromatic amino acids. This surplus of aromatic amino acids is used to reinforce the insect's protective cuticle. An exceptional feature of the Sitophilus oryzae/Sodalis pierantonius interaction is the exponential increase in endosymbiotic titer observed in young adult insects, in concomitance with cuticle biosynthesis. Here, we show that host carbohydrate intake triggers endosymbiont exponential proliferation, even in conditions that lead to the detriment of the host survival. In addition, when hosts thrive on a balanced diet, endosymbiont proliferation is dispensable for several host fitness traits. The endosymbiont exponential proliferation is therefore dependent on the nutritional status of the host, and its consequences on host cuticle biosynthesis and survival depend on food quality and availability.
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Djoukzoumka S, Mahamat Hassane H, Khan Payne V, Ibrahim MAM, Tagueu Kanté S, Mouliom Mfopit Y, Berger P, Kelm S, Simo G. Sodalis glossinidius and Wolbachia infections in wild population of Glossina morsitans submorsitans caught in the area of Lake Iro in the south of Chad. J Invertebr Pathol 2022; 195:107835. [DOI: 10.1016/j.jip.2022.107835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 10/01/2022] [Accepted: 10/07/2022] [Indexed: 10/31/2022]
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Ferrarini MG, Dell’Aglio E, Vallier A, Balmand S, Vincent-Monégat C, Hughes S, Gillet B, Parisot N, Zaidman-Rémy A, Vieira C, Heddi A, Rebollo R. Efficient compartmentalization in insect bacteriomes protects symbiotic bacteria from host immune system. MICROBIOME 2022; 10:156. [PMID: 36163269 PMCID: PMC9513942 DOI: 10.1186/s40168-022-01334-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Accepted: 07/25/2022] [Indexed: 06/16/2023]
Abstract
BACKGROUND Many insects house symbiotic intracellular bacteria (endosymbionts) that provide them with essential nutrients, thus promoting the usage of nutrient-poor habitats. Endosymbiont seclusion within host specialized cells, called bacteriocytes, often organized in a dedicated organ, the bacteriome, is crucial in protecting them from host immune defenses while avoiding chronic host immune activation. Previous evidence obtained in the cereal weevil Sitophilus oryzae has shown that bacteriome immunity is activated against invading pathogens, suggesting endosymbionts might be targeted and impacted by immune effectors during an immune challenge. To pinpoint any molecular determinants associated with such challenges, we conducted a dual transcriptomic analysis of S. oryzae's bacteriome subjected to immunogenic peptidoglycan fragments. RESULTS We show that upon immune challenge, the bacteriome actively participates in the innate immune response via induction of antimicrobial peptides (AMPs). Surprisingly, endosymbionts do not undergo any transcriptomic changes, indicating that this potential threat goes unnoticed. Immunohistochemistry showed that TCT-induced AMPs are located outside the bacteriome, excluding direct contact with the endosymbionts. CONCLUSIONS This work demonstrates that endosymbiont protection during an immune challenge is mainly achieved by efficient confinement within bacteriomes, which provides physical separation between host systemic response and endosymbionts. Video Abstract.
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Affiliation(s)
- Mariana Galvão Ferrarini
- Univ Lyon, INRAE, INSA-Lyon, BF2I, UMR 203, 69621 Villeurbanne, France
- Laboratoire de Biométrie et Biologie Evolutive, UMR5558, Université Lyon 1, Université Lyon, Villeurbanne, France
| | - Elisa Dell’Aglio
- Univ Lyon, INRAE, INSA-Lyon, BF2I, UMR 203, 69621 Villeurbanne, France
| | - Agnès Vallier
- Univ Lyon, INRAE, INSA-Lyon, BF2I, UMR 203, 69621 Villeurbanne, France
| | - Séverine Balmand
- Univ Lyon, INRAE, INSA-Lyon, BF2I, UMR 203, 69621 Villeurbanne, France
| | | | - Sandrine Hughes
- UMR5242, Institut de Génomique Fonctionnelle de Lyon (IGFL), Ecole Normale Supérieure de Lyon, Centre National de la Recherche Scientifique (CNRS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon (Univ Lyon), F-69007 Lyon, France
| | - Benjamin Gillet
- UMR5242, Institut de Génomique Fonctionnelle de Lyon (IGFL), Ecole Normale Supérieure de Lyon, Centre National de la Recherche Scientifique (CNRS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon (Univ Lyon), F-69007 Lyon, France
| | - Nicolas Parisot
- Univ Lyon, INSA-Lyon, INRAE, BF2I, UMR 203, 69621 Villeurbanne, France
| | - Anna Zaidman-Rémy
- Univ Lyon, INSA-Lyon, INRAE, BF2I, UMR 203, 69621 Villeurbanne, France
| | - Cristina Vieira
- Laboratoire de Biométrie et Biologie Evolutive, UMR5558, Université Lyon 1, Université Lyon, Villeurbanne, France
| | - Abdelaziz Heddi
- Univ Lyon, INSA-Lyon, INRAE, BF2I, UMR 203, 69621 Villeurbanne, France
| | - Rita Rebollo
- Univ Lyon, INRAE, INSA-Lyon, BF2I, UMR 203, 69621 Villeurbanne, France
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Opiro R, Opoke R, Angwech H, Nakafu E, Oloya FA, Openy G, Njahira M, Macharia M, Echodu R, Malinga GM, Opiyo EA. Apparent density, trypanosome infection rates and host preference of tsetse flies in the sleeping sickness endemic focus of northwestern Uganda. BMC Vet Res 2021; 17:365. [PMID: 34839816 PMCID: PMC8628410 DOI: 10.1186/s12917-021-03071-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 11/13/2021] [Indexed: 11/11/2022] Open
Abstract
Background African trypanosomiasis, caused by protozoa of the genus Trypanosoma and transmitted by the tsetse fly, is a serious parasitic disease of humans and animals. Reliable data on the vector distribution, feeding preference and the trypanosome species they carry is pertinent to planning sustainable control strategies. Methodology We deployed 109 biconical traps in 10 villages in two districts of northwestern Uganda to obtain information on the apparent density, trypanosome infection status and blood meal sources of tsetse flies. A subset (272) of the collected samples was analyzed for detection of trypanosomes species and sub-species using a nested PCR protocol based on primers amplifying the Internal Transcribed Spacer (ITS) region of ribosomal DNA. 34 blood-engorged adult tsetse midguts were analyzed for blood meal sources by sequencing of the mitochondrial cytochrome c oxidase 1 (COI) and cytochrome b (cytb) genes. Results We captured a total of 622 Glossina fuscipes fuscipes tsetse flies (269 males and 353 females) in the two districts with apparent density (AD) ranging from 0.6 to 3.7 flies/trap/day (FTD). 10.7% (29/272) of the flies were infected with one or more trypanosome species. Infection rate was not significantly associated with district of origin (Generalized linear model (GLM), χ2 = 0.018, P = 0.895, df = 1, n = 272) and sex of the fly (χ2 = 1.723, P = 0.189, df = 1, n = 272). However, trypanosome infection was highly significantly associated with the fly’s age based on wing fray category (χ2 = 22.374, P < 0.001, df = 1, n = 272), being higher among the very old than the young tsetse. Nested PCR revealed several species of trypanosomes: T. vivax (6.62%), T. congolense (2.57%), T. brucei and T. simiae each at 0.73%. Blood meal analyses revealed five principal vertebrate hosts, namely, cattle (Bos taurus), humans (Homo sapiens), Nile monitor lizard (Varanus niloticus), African mud turtle (Pelusios chapini) and the African Savanna elephant (Loxodonta africana). Conclusion We found an infection rate of 10.8% in the tsetse sampled, with all infections attributed to trypanosome species that are causative agents for AAT. However, more verification of this finding using large-scale passive and active screening of human and tsetse samples should be done. Cattle and humans appear to be the most important tsetse hosts in the region and should be considered in the design of control interventions.
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Affiliation(s)
- Robert Opiro
- Department of Biology, Faculty of Science, Gulu University, P.O Box 166, Gulu, Uganda.
| | - Robert Opoke
- Department of Biology, Faculty of Science, Muni University, P.O Box 725, Arua, Uganda
| | - Harriet Angwech
- Department of Biology, Faculty of Science, Gulu University, P.O Box 166, Gulu, Uganda
| | - Esther Nakafu
- Department of Molecular Biology, College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, P.O Box 7062, Kampala, Uganda
| | - Francis A Oloya
- Department of Biology, Faculty of Science, Gulu University, P.O Box 166, Gulu, Uganda
| | - Geoffrey Openy
- Department of Biosystems Engineering, Faculty of Agriculture and Environment, Gulu University, P. O Box 166, Gulu, Uganda
| | - Moses Njahira
- Biosciences Eastern and Central Africa-International Livestock Research Institute Hub, P. O Box 30709, Nairobi, Kenya
| | - Mercy Macharia
- Biosciences Eastern and Central Africa-International Livestock Research Institute Hub, P. O Box 30709, Nairobi, Kenya
| | - Richard Echodu
- Department of Biology, Faculty of Science, Gulu University, P.O Box 166, Gulu, Uganda
| | - Geoffrey M Malinga
- Department of Biology, Faculty of Science, Gulu University, P.O Box 166, Gulu, Uganda.,Department of Forestry, Biodiversity and Tourism, Makerere University, PO Box 7062, Kampala, Uganda
| | - Elizabeth A Opiyo
- Department of Biology, Faculty of Science, Gulu University, P.O Box 166, Gulu, Uganda
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Wudil UJ, Aliyu MH, Prigmore HL, Ingles DJ, Ahonkhai AA, Musa BM, Muhammad H, Sani MU, Nalado AM, Abdu A, Abdussalam K, Shepherd BE, Dankishiya FS, Burgner AM, Ikizler TA, Wyatt CM, Kopp JB, Kimmel PL, Winkler CA, Wester CW. Apolipoprotein-1 risk variants and associated kidney phenotypes in an adult HIV cohort in Nigeria. Kidney Int 2021; 100:146-154. [PMID: 33901548 PMCID: PMC8487768 DOI: 10.1016/j.kint.2021.03.038] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 03/03/2021] [Accepted: 03/11/2021] [Indexed: 12/17/2022]
Abstract
HIV-positive adults are at risk for various kidney diseases, and apolipoprotein 1 (APOL1) high-risk genotypes increase this risk. This study aimed to determine the prevalence and ethnic distribution of APOL1 risk genotypes among a cohort of HIV-positive Nigerian adults and explore the relationship between APOL1 risk variant status with albuminuria and estimated glomerular filtration rate (eGFR). We conducted a cross-sectional study among 2 458 persons living with HIV who attended an HIV clinic in northern Nigeria and had received antiretroviral therapy for a minimum of six months. We collected two urine samples four-eight weeks apart to measure albumin excretion, and blood samples to measure eGFR and determine APOL1 genotype. The frequency of APOL1 high-risk genotype was 6.2%, which varied by ethnic group: Hausa/Fulani (2.1%), Igbo (49.1%), and Yoruba (14.5%). The prevalence of microalbuminuria (urine/albumin creatinine ratio 30- 300 mg/g) was 37%, and prevalence of macroalbuminuria (urine/albumin creatinine ratio over 300 mg/g) was 3%. The odds of microalbuminuria and macroalbuminuria were higher for participants with the APOL1 high-risk genotype compared to those carrying the low-risk genotype ([adjusted odds ratio 1.97, 95% confidence interval 1.37-2.82] and [3.96, 1.95-8.02] respectively). APOL1 high-risk genotype participants were at higher risk of having both an eGFR under 60 ml/min/1.73m2 and urine/albumin creatinine ratio over 300 mg/g (5.56, 1.57-19.69). Thus, we found a high proportion of HIV-positive, antiretroviral therapy-experienced, and largely virologically suppressed adults had microalbuminuria. Hence, although the high-risk APOL1 genotype was less prevalent than expected, it was strongly associated with some level of albuminuria.
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Affiliation(s)
- Usman J Wudil
- Vanderbilt Institute for Global Health, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Muktar H Aliyu
- Vanderbilt Institute for Global Health, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Department of Health Policy, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Heather L Prigmore
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Donna J Ingles
- Vanderbilt Institute for Global Health, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Aima A Ahonkhai
- Vanderbilt Institute for Global Health, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Department of Medicine, Division of Infectious Diseases, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Baba M Musa
- Department of Medicine, Aminu Kano Teaching Hospital, Kano, Nigeria; Africa Center of Excellence for Population Health and Policy, Bayero University, Kano, Nigeria
| | - Hamza Muhammad
- Department of Medicine, Aminu Kano Teaching Hospital, Kano, Nigeria
| | - Mahmoud U Sani
- Department of Medicine, Aminu Kano Teaching Hospital, Kano, Nigeria
| | - Aisha M Nalado
- Department of Medicine, Aminu Kano Teaching Hospital, Kano, Nigeria
| | - Aliyu Abdu
- Department of Medicine, Aminu Kano Teaching Hospital, Kano, Nigeria
| | - Kabiru Abdussalam
- Department of Chemical Pathology, Aminu Kano Teaching Hospital, Kano, Nigeria
| | - Bryan E Shepherd
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | | | - Anna M Burgner
- Department of Medicine, Division of Nephrology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - T Alp Ikizler
- Department of Medicine, Division of Nephrology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Christina M Wyatt
- Department of Medicine, Division of Nephrology, Duke University School of Medicine, Duke Clinical Research Institute, Durham, North Carolina, USA
| | - Jeffrey B Kopp
- Kidney Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland, USA
| | - Paul L Kimmel
- Kidney Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland, USA
| | - Cheryl A Winkler
- Basic Research Laboratory, Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA
| | - C William Wester
- Vanderbilt Institute for Global Health, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Department of Medicine, Division of Infectious Diseases, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
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Kasozi KI, Zirintunda G, Ssempijja F, Buyinza B, Alzahrani KJ, Matama K, Nakimbugwe HN, Alkazmi L, Onanyang D, Bogere P, Ochieng JJ, Islam S, Matovu W, Nalumenya DP, Batiha GES, Osuwat LO, Abdelhamid M, Shen T, Omadang L, Welburn SC. Epidemiology of Trypanosomiasis in Wildlife-Implications for Humans at the Wildlife Interface in Africa. Front Vet Sci 2021; 8:621699. [PMID: 34222391 PMCID: PMC8248802 DOI: 10.3389/fvets.2021.621699] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 05/05/2021] [Indexed: 12/18/2022] Open
Abstract
While both human and animal trypanosomiasis continue to present as major human and animal public health constraints globally, detailed analyses of trypanosome wildlife reservoir hosts remain sparse. African animal trypanosomiasis (AAT) affects both livestock and wildlife carrying a significant risk of spillover and cross-transmission of species and strains between populations. Increased human activity together with pressure on land resources is increasing wildlife–livestock–human infections. Increasing proximity between human settlements and grazing lands to wildlife reserves and game parks only serves to exacerbate zoonotic risk. Communities living and maintaining livestock on the fringes of wildlife-rich ecosystems require to have in place methods of vector control for prevention of AAT transmission and for the treatment of their livestock. Major Trypanosoma spp. include Trypanosoma brucei rhodesiense, Trypanosoma brucei gambiense, and Trypanosoma cruzi, pathogenic for humans, and Trypanosoma vivax, Trypanosoma congolense, Trypanosoma evansi, Trypanosoma brucei brucei, Trypanosoma dionisii, Trypanosoma thomasbancrofti, Trypanosma elephantis, Trypanosoma vegrandis, Trypanosoma copemani, Trypanosoma irwini, Trypanosoma copemani, Trypanosoma gilletti, Trypanosoma theileri, Trypanosoma godfreyi, Trypansoma simiae, and Trypanosoma (Megatrypanum) pestanai. Wildlife hosts for the trypansomatidae include subfamilies of Bovinae, Suidae, Pantherinae, Equidae, Alcephinae, Cercopithecinae, Crocodilinae, Pteropodidae, Peramelidae, Sigmodontidae, and Meliphagidae. Wildlife species are generally considered tolerant to trypanosome infection following centuries of coexistence of vectors and wildlife hosts. Tolerance is influenced by age, sex, species, and physiological condition and parasite challenge. Cyclic transmission through Glossina species occurs for T. congolense, T. simiae, T. vivax, T. brucei, and T. b. rhodesiense, T. b. gambiense, and within Reduviid bugs for T. cruzi. T. evansi is mechanically transmitted, and T. vixax is also commonly transmitted by biting flies including tsetse. Wildlife animal species serve as long-term reservoirs of infection, but the delicate acquired balance between trypanotolerance and trypanosome challenge can be disrupted by an increase in challenge and/or the introduction of new more virulent species into the ecosystem. There is a need to protect wildlife, animal, and human populations from the infectious consequences of encroachment to preserve and protect these populations. In this review, we explore the ecology and epidemiology of Trypanosoma spp. in wildlife.
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Affiliation(s)
- Keneth Iceland Kasozi
- Infection Medicine, Deanery of Biomedical Sciences, College of Medicine and Veterinary Medicine, The University of Edinburgh, Scotland, United Kingdom.,School of Medicine, Kabale University, Kabale, Uganda
| | - Gerald Zirintunda
- Department of Animal Production and Management, Faculty of Agriculture and Animal Sciences, Busitema University Arapai Campus, Soroti, Uganda
| | - Fred Ssempijja
- Faculty of Biomedical Sciences, Kampala International University Western Campus, Bushenyi, Uganda
| | - Bridget Buyinza
- College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Khalid J Alzahrani
- Department of Clinical Laboratories Sciences, College of Applied Medical Sciences, Taif University, Taif, Saudi Arabia
| | - Kevin Matama
- School of Pharmacy, Kampala International University Western Campus, Bushenyi, Uganda
| | - Helen N Nakimbugwe
- Department of Animal Production and Management, Faculty of Agriculture and Animal Sciences, Busitema University Arapai Campus, Soroti, Uganda.,Department of Agriculture, Faculty of Vocational Studies, Kyambogo University, Kampala, Uganda
| | - Luay Alkazmi
- Biology Department, Faculty of Applied Sciences, Umm Al-Qura University, Makkah, Saudi Arabia
| | - David Onanyang
- Department of Biology, Faculty of Science, Gulu University, Gulu, Uganda
| | - Paul Bogere
- Faculty of Agriculture and Environmental Science, Muni University, Arua, Uganda
| | - Juma John Ochieng
- Faculty of Biomedical Sciences, Kampala International University Western Campus, Bushenyi, Uganda
| | - Saher Islam
- Department of Biotechnology, Lahore College for Women University, Lahore, Pakistan
| | - Wycliff Matovu
- College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - David Paul Nalumenya
- College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Gaber El-Saber Batiha
- Department of Pharmacology and Therapeutics, Faculty of Veterinary Medicine, Damanhour University, Damanhour, Egypt
| | | | - Mahmoud Abdelhamid
- Department of Parasitology, Faculty of Veterinary Medicine, Aswan University, Aswan, Egypt
| | - Tianren Shen
- Infection Medicine, Deanery of Biomedical Sciences, College of Medicine and Veterinary Medicine, The University of Edinburgh, Scotland, United Kingdom.,Zhejiang University-University of Edinburgh Institute, Zhejiang University School of Medicine, Zhejiang University, Haining, China
| | - Leonard Omadang
- Department of Animal Production and Management, Faculty of Agriculture and Animal Sciences, Busitema University Arapai Campus, Soroti, Uganda
| | - Susan Christina Welburn
- Infection Medicine, Deanery of Biomedical Sciences, College of Medicine and Veterinary Medicine, The University of Edinburgh, Scotland, United Kingdom.,Zhejiang University-University of Edinburgh Institute, Zhejiang University School of Medicine, Zhejiang University, Haining, China
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Vreysen MJB, Abd-Alla AMM, Bourtzis K, Bouyer J, Caceres C, de Beer C, Oliveira Carvalho D, Maiga H, Mamai W, Nikolouli K, Yamada H, Pereira R. The Insect Pest Control Laboratory of the Joint FAO/IAEA Programme: Ten Years (2010-2020) of Research and Development, Achievements and Challenges in Support of the Sterile Insect Technique. INSECTS 2021; 12:346. [PMID: 33924539 PMCID: PMC8070182 DOI: 10.3390/insects12040346] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 03/30/2021] [Accepted: 04/01/2021] [Indexed: 02/06/2023]
Abstract
The Joint FAO/IAEA Centre (formerly called Division) of Nuclear Techniques in Food and Agriculture was established in 1964 and its accompanying laboratories in 1961. One of its subprograms deals with insect pest control, and has the mandate to develop and implement the sterile insect technique (SIT) for selected key insect pests, with the goal of reducing the use of insecticides, reducing animal and crop losses, protecting the environment, facilitating international trade in agricultural commodities and improving human health. Since its inception, the Insect Pest Control Laboratory (IPCL) (formerly named Entomology Unit) has been implementing research in relation to the development of the SIT package for insect pests of crops, livestock and human health. This paper provides a review of research carried out between 2010 and 2020 at the IPCL. Research on plant pests has focused on the development of genetic sexing strains, characterizing and assessing the performance of these strains (e.g., Ceratitis capitata), elucidation of the taxonomic status of several members of the Bactrocera dorsalis and Anastrepha fraterculus complexes, the use of microbiota as probiotics, genomics, supplements to improve the performance of the reared insects, and the development of the SIT package for fruit fly species such as Bactrocera oleae and Drosophila suzukii. Research on livestock pests has focused on colony maintenance and establishment, tsetse symbionts and pathogens, sex separation, morphology, sterile male quality, radiation biology, mating behavior and transportation and release systems. Research with human disease vectors has focused on the development of genetic sexing strains (Anopheles arabiensis, Aedes aegypti and Aedes albopictus), the development of a more cost-effective larvae and adult rearing system, assessing various aspects of radiation biology, characterizing symbionts and pathogens, studying mating behavior and the development of quality control procedures, and handling and release methods. During the review period, 13 coordinated research projects (CRPs) were completed and six are still being implemented. At the end of each CRP, the results were published in a special issue of a peer-reviewed journal. The review concludes with an overview of future challenges, such as the need to adhere to a phased conditional approach for the implementation of operational SIT programs, the need to make the SIT more cost effective, to respond with demand driven research to solve the problems faced by the operational SIT programs and the use of the SIT to address a multitude of exotic species that are being introduced, due to globalization, and established in areas where they could not survive before, due to climate change.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Hanano Yamada
- Insect Pest Control Subprogramme, Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, A-1400 Vienna, Austria; (M.J.B.V.); (A.M.M.A.-A.); (K.B.); (J.B.); (C.C.); (C.d.B.); (D.O.C.); (H.M.); (W.M.); (K.N.); (R.P.)
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8
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Diallo S, Shahbaaz M, Makwatta JO, Muema JM, Masiga D, Christofells A, Getahun MN. Antennal Enriched Odorant Binding Proteins Are Required for Odor Communication in Glossina f. fuscipes. Biomolecules 2021; 11:541. [PMID: 33917773 PMCID: PMC8068202 DOI: 10.3390/biom11040541] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 03/31/2021] [Indexed: 02/07/2023] Open
Abstract
Olfaction is orchestrated at different stages and involves various proteins at each step. For example, odorant-binding proteins (OBPs) are soluble proteins found in sensillum lymph that might encounter odorants before reaching the odorant receptors. In tsetse flies, the function of OBPs in olfaction is less understood. Here, we investigated the role of OBPs in Glossina fuscipes fuscipes olfaction, the main vector of sleeping sickness, using multidisciplinary approaches. Our tissue expression study demonstrated that GffLush was conserved in legs and antenna in both sexes, whereas GffObp44 and GffObp69 were expressed in the legs but absent in the antenna. GffObp99 was absent in the female antenna but expressed in the male antenna. Short odorant exposure induced a fast alteration in the transcription of OBP genes. Furthermore, we successfully silenced a specific OBP expressed in the antenna via dsRNAi feeding to decipher its function. We found that silencing OBPs that interact with 1-octen-3-ol significantly abolished flies' attraction to 1-octen-3-ol, a known attractant for tsetse fly. However, OBPs that demonstrated a weak interaction with 1-octen-3-ol did not affect the behavioral response, even though it was successfully silenced. Thus, OBPs' selective interaction with ligands, their expression in the antenna and their significant impact on behavior when silenced demonstrated their direct involvement in olfaction.
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Affiliation(s)
- Souleymane Diallo
- International Centre of Insect Physiology and Ecology (ICIPE), Nairobi P.O. Box 30772-00100, Kenya
- South African Medical Research Council Bioinformatics Unit, South African National Bioinformatics Institute (SANBI), University of the Western Cape, Private Bag X17, Bellville 7535, South Africa
| | - Mohd Shahbaaz
- South African Medical Research Council Bioinformatics Unit, South African National Bioinformatics Institute (SANBI), University of the Western Cape, Private Bag X17, Bellville 7535, South Africa
| | - JohnMark O Makwatta
- International Centre of Insect Physiology and Ecology (ICIPE), Nairobi P.O. Box 30772-00100, Kenya
| | - Jackson M Muema
- International Centre of Insect Physiology and Ecology (ICIPE), Nairobi P.O. Box 30772-00100, Kenya
| | - Daniel Masiga
- International Centre of Insect Physiology and Ecology (ICIPE), Nairobi P.O. Box 30772-00100, Kenya
| | - Alan Christofells
- South African Medical Research Council Bioinformatics Unit, South African National Bioinformatics Institute (SANBI), University of the Western Cape, Private Bag X17, Bellville 7535, South Africa
| | - Merid N Getahun
- International Centre of Insect Physiology and Ecology (ICIPE), Nairobi P.O. Box 30772-00100, Kenya
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9
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Bateta R, Saarman NP, Okeyo WA, Dion K, Johnson T, Mireji PO, Okoth S, Malele I, Murilla G, Aksoy S, Caccone A. Phylogeography and population structure of the tsetse fly Glossina pallidipes in Kenya and the Serengeti ecosystem. PLoS Negl Trop Dis 2020; 14:e0007855. [PMID: 32092056 PMCID: PMC7058365 DOI: 10.1371/journal.pntd.0007855] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 03/05/2020] [Accepted: 10/17/2019] [Indexed: 02/06/2023] Open
Abstract
Glossina pallidipes is the main vector of animal African trypanosomiasis and a potential vector of human African trypanosomiasis in eastern Africa where it poses a large economic burden and public health threat. Vector control efforts have succeeded in reducing infection rates, but recent resurgence in tsetse fly population density raises concerns that vector control programs require improved strategic planning over larger geographic and temporal scales. Detailed knowledge of population structure and dispersal patterns can provide the required information to improve planning. To this end, we investigated the phylogeography and population structure of G. pallidipes over a large spatial scale in Kenya and northern Tanzania using 11 microsatellite loci genotyped in 600 individuals. Our results indicate distinct genetic clusters east and west of the Great Rift Valley, and less distinct clustering of the northwest separate from the southwest (Serengeti ecosystem). Estimates of genetic differentiation and first-generation migration indicated high genetic connectivity within genetic clusters even across large geographic distances of more than 300 km in the east, but only occasional migration among clusters. Patterns of connectivity suggest isolation by distance across genetic breaks but not within genetic clusters, and imply a major role for river basins in facilitating gene flow in G. pallidipes. Effective population size (Ne) estimates and results from Approximate Bayesian Computation further support that there has been recent G. pallidipes population size fluctuations in the Serengeti ecosystem and the northwest during the last century, but also suggest that the full extent of differences in genetic diversity and population dynamics between the east and the west was established over evolutionary time periods (tentatively on the order of millions of years). Findings provide further support that the Serengeti ecosystem and northwestern Kenya represent independent tsetse populations. Additionally, we present evidence that three previously recognized populations (the Mbeere-Meru, Central Kenya and Coastal "fly belts") act as a single population and should be considered as a single unit in vector control.
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Affiliation(s)
- Rosemary Bateta
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Kikuyu, Nairobi, Kenya
| | - Norah P. Saarman
- Department of Ecology and Evolutionary Biology, Yale University, Connecticut, United States of America
- * E-mail:
| | - Winnie A. Okeyo
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Kikuyu, Nairobi, Kenya
- Department of Biomedical Sciences and Technology, School of Public Health and Community Development, Maseno University, Maseno, Kisumu, Kenya
| | - Kirstin Dion
- Department of Ecology and Evolutionary Biology, Yale University, Connecticut, United States of America
| | - Thomas Johnson
- Department of Ecology and Evolutionary Biology, Yale University, Connecticut, United States of America
| | - Paul O. Mireji
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Kikuyu, Nairobi, Kenya
- Centre for Geographic Medicine Research Coast, Kenya Medical Research Institute, Kilifi, Kenya
| | - Sylvance Okoth
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Kikuyu, Nairobi, Kenya
| | - Imna Malele
- Vector and Vector Borne Diseases Research Institute, Tanzania Veterinary Laboratory Agency, Tanga, Tanzania
| | - Grace Murilla
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Kikuyu, Nairobi, Kenya
| | - Serap Aksoy
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, Connecticut, United States of America
| | - Adalgisa Caccone
- Department of Ecology and Evolutionary Biology, Yale University, Connecticut, United States of America
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10
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Saarman NP, Opiro R, Hyseni C, Echodu R, Opiyo EA, Dion K, Johnson T, Aksoy S, Caccone A. The population genomics of multiple tsetse fly (Glossina fuscipes fuscipes) admixture zones in Uganda. Mol Ecol 2019; 28:66-85. [PMID: 30471158 DOI: 10.1111/mec.14957] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 10/26/2018] [Accepted: 11/05/2018] [Indexed: 11/28/2022]
Abstract
Understanding the mechanisms that enforce, maintain or reverse the process of speciation is an important challenge in evolutionary biology. This study investigates the patterns of divergence and discusses the processes that form and maintain divergent lineages of the tsetse fly Glossina fuscipes fuscipes in Uganda. We sampled 251 flies from 18 sites spanning known genetic lineages and the four admixture zones between them. We apply population genomics, hybrid zone and approximate Bayesian computation to the analysis of three types of genetic markers: 55,267 double-digest restriction site-associated DNA (ddRAD) SNPs to assess genome-wide admixture, 16 microsatellites to provide continuity with published data and accurate biogeographic modelling, and a 491-bp fragment of mitochondrial cytochrome oxidase I and II to infer maternal inheritance patterns. Admixture zones correspond with regions impacted by the reorganization of Uganda's river networks that occurred during the formation of the West African Rift system over the last several hundred thousand years. Because tsetse fly population distributions are defined by rivers, admixture zones likely represent both old and new regions of secondary contact. Our results indicate that older hybrid zones contain mostly parental types, while younger zones contain variable hybrid types resulting from multiple generations of interbreeding. These findings suggest that reproductive barriers are nearly complete in the older admixture zones, while nearly absent in the younger admixture zones. Findings are consistent with predictions of hybrid zone theory: Populations in zones of secondary contact transition rapidly from early to late stages of speciation or collapse all together.
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Affiliation(s)
- Norah P Saarman
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut
| | - Robert Opiro
- Department of Biology, Faculty of Science, Gulu University, Uganda
| | - Chaz Hyseni
- Department of Biology, University of Mississippi, Oxford, Mississippi
| | - Richard Echodu
- Department of Biology, Faculty of Science, Gulu University, Uganda
| | | | - Kirstin Dion
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut
| | - Thomas Johnson
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut
| | - Serap Aksoy
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut
| | - Adalgisa Caccone
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut
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11
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Schneider DI, Saarman N, Onyango MG, Hyseni C, Opiro R, Echodu R, O’Neill M, Bloch D, Vigneron A, Johnson TJ, Dion K, Weiss BL, Opiyo E, Caccone A, Aksoy S. Spatio-temporal distribution of Spiroplasma infections in the tsetse fly (Glossina fuscipes fuscipes) in northern Uganda. PLoS Negl Trop Dis 2019; 13:e0007340. [PMID: 31369548 PMCID: PMC6692048 DOI: 10.1371/journal.pntd.0007340] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Revised: 08/13/2019] [Accepted: 07/13/2019] [Indexed: 12/13/2022] Open
Abstract
Tsetse flies (Glossina spp.) are vectors of parasitic trypanosomes, which cause human (HAT) and animal African trypanosomiasis (AAT) in sub-Saharan Africa. In Uganda, Glossina fuscipes fuscipes (Gff) is the main vector of HAT, where it transmits Gambiense disease in the northwest and Rhodesiense disease in central, southeast and western regions. Endosymbionts can influence transmission efficiency of parasites through their insect vectors via conferring a protective effect against the parasite. It is known that the bacterium Spiroplasma is capable of protecting its Drosophila host from infection with a parasitic nematode. This endosymbiont can also impact its host's population structure via altering host reproductive traits. Here, we used field collections across 26 different Gff sampling sites in northern and western Uganda to investigate the association of Spiroplasma with geographic origin, seasonal conditions, Gff genetic background and sex, and trypanosome infection status. We also investigated the influence of Spiroplasma on Gff vector competence to trypanosome infections under laboratory conditions. Generalized linear models (GLM) showed that Spiroplasma probability was correlated with the geographic origin of Gff host and with the season of collection, with higher prevalence found in flies within the Albert Nile (0.42 vs 0.16) and Achwa River (0.36 vs 0.08) watersheds and with higher prevalence detected in flies collected in the intermediate than wet season. In contrast, there was no significant correlation of Spiroplasma prevalence with Gff host genetic background or sex once geographic origin was accounted for in generalized linear models. Additionally, we found a potential negative correlation of Spiroplasma with trypanosome infection, with only 2% of Spiroplasma infected flies harboring trypanosome co-infections. We also found that in a laboratory line of Gff, parasitic trypanosomes are less likely to colonize the midgut in individuals that harbor Spiroplasma infection. These results indicate that Spiroplasma infections in tsetse may be maintained by not only maternal but also via horizontal transmission routes, and Spiroplasma infections may also have important effects on trypanosome transmission efficiency of the host tsetse. Potential functional effects of Spiroplasma infection in Gff could have impacts on vector control approaches to reduce trypanosome infections.
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Affiliation(s)
- Daniela I. Schneider
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, United States of America
- * E-mail:
| | - Norah Saarman
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, United States of America
| | - Maria G. Onyango
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, United States of America
| | - Chaz Hyseni
- Department of Biology, University of Mississippi, University, MS, United States of America
| | - Robert Opiro
- Department of Biology, Faculty of Science, Gulu University, Uganda
| | - Richard Echodu
- Department of Biology, Faculty of Science, Gulu University, Uganda
| | - Michelle O’Neill
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, United States of America
| | - Danielle Bloch
- Department of Health and Mental Hygiene, New York City, NY, United States of America
| | - Aurélien Vigneron
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, United States of America
| | - T. J. Johnson
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, United States of America
| | - Kirstin Dion
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, United States of America
| | - Brian L. Weiss
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, United States of America
| | - Elizabeth Opiyo
- Department of Biology, University of Mississippi, University, MS, United States of America
| | - Adalgisa Caccone
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, United States of America
| | - Serap Aksoy
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, United States of America
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Abstract
Parasites elicit several physiological changes in their host to enhance transmission. Little is known about the functional association between parasitism and microbiota-provisioned resources typically dedicated to animal hosts and how these goods may be rerouted to optimize parasite development. This study is the first to identify a specific symbiont-generated metabolite that impacts insect vector competence by facilitating parasite establishment and, thus, eventual transmission. Specifically, we demonstrate that the tsetse fly obligate mutualist Wigglesworthia provisions folate (vitamin B9) that pathogenic African trypanosomes exploit in an effort to successfully establish an infection in the vector’s MG. This process is essential for the parasite to complete its life cycle and be transmitted to a new vertebrate host. Disrupting metabolic contributions provided by the microbiota of arthropod disease vectors may fuel future innovative control strategies while also offering minimal nontarget effects. Many symbionts supplement their host’s diet with essential nutrients. However, whether these nutrients also enhance parasitism is unknown. In this study, we investigated whether folate (vitamin B9) production by the tsetse fly (Glossina spp.) essential mutualist, Wigglesworthia, aids auxotrophic African trypanosomes in completing their life cycle within this obligate vector. We show that the expression of Wigglesworthia folate biosynthesis genes changes with the progression of trypanosome infection within tsetse. The disruption of Wigglesworthia folate production caused a reduction in the percentage of flies that housed midgut (MG) trypanosome infections. However, decreased folate did not prevent MG trypanosomes from migrating to and establishing an infection in the fly’s salivary glands, thus suggesting that nutrient requirements vary throughout the trypanosome life cycle. We further substantiated that trypanosomes rely on symbiont-generated folate by feeding this vitamin to Glossina brevipalpis, which exhibits low trypanosome vector competency and houses Wigglesworthia incapable of producing folate. Folate-supplemented G. brevipalpis flies were significantly more susceptible to trypanosome infection, further demonstrating that this vitamin facilitates parasite infection establishment. Our cumulative results provide evidence that Wigglesworthia provides a key metabolite (folate) that is “hijacked” by trypanosomes to enhance their infectivity, thus indirectly impacting tsetse species vector competency. Parasite dependence on symbiont-derived micronutrients, which likely also occurs in other arthropod vectors, represents a relationship that may be exploited to reduce disease transmission.
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Simo G, Kanté ST, Madinga J, Kame G, Farikou O, Ilombe G, Geiger A, Lutumba P, Njiokou F. Molecular identification of Wolbachia and Sodalis glossinidius in the midgut of Glossina fuscipes quanzensis from the Democratic Republic of Congo. ACTA ACUST UNITED AC 2019; 26:5. [PMID: 30729921 PMCID: PMC6366345 DOI: 10.1051/parasite/2019005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 01/23/2019] [Indexed: 11/20/2022]
Abstract
During the last 30 years, investigations on the microbiome of different tsetse species have generated substantial data on the bacterial flora of these cyclical vectors of African trypanosomes, with the overarching goal of improving the control of trypanosomiases. It is in this context that the presence of Wolbachia and Sodalis glossinidius was studied in wild populations of Glossina fuscipes quanzensis from the Democratic Republic of Congo. Tsetse flies were captured with pyramidal traps. Of the 700 Glossina f. quanzensis captured, 360 were dissected and their midguts collected and analyzed. Sodalis glossinidius and Wolbachia were identified by PCR. The Wolbachia-positive samples were genetically characterized with five molecular markers. PCR revealed 84.78% and 15.55% midguts infected by Wolbachia and S. glossinidius, respectively. The infection rates varied according to capture sites. Of the five molecular markers used to characterize Wolbachia, only the fructose bis-phosphate aldolase gene was amplified for about 60% of midguts previously found with Wolbachia infections. The sequencing results confirmed the presence of Wolbachia and revealed the presence of S. glossinidius in the midgut of Glossina f. quanzensis. A low level of midguts were naturally co-infected by both bacteria. The data generated in this study open a framework for investigations aimed at understanding the contribution of these symbiotic microorganisms to the vectorial competence of Glossina fuscipes quanzensis.
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Affiliation(s)
- Gustave Simo
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, PO Box 67, Dschang, Cameroon
| | - Sartrien Tagueu Kanté
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, PO Box 67, Dschang, Cameroon
| | - Joule Madinga
- Institute of Health and Society, Université Catholique de Louvain, Clos Chapelle-aux-Champs 30, 1200 Woluwe-Saint-Lambert, Brussels, Belgium - Department of Biomedical Sciences, Institute of Tropical Medicine, Nationalestraat 155, 2000, Antwerp, Belgium
| | - Ginette Kame
- Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé I, PO Box 812 Yaoundé, Cameroon
| | - Oumarou Farikou
- Mission Spéciale d'Eradication des Glossines, Division Régionale Tsé-Tsé Adamaoua, PO Box 263 Ngaoundéré, Cameroon
| | - Gillon Ilombe
- Institut national de recherche biomédicale Kinshasa, Avenue de la démocratie N°5345, Gombe, Kinshasa, Democratic Republic of Congo
| | - Anne Geiger
- UMR 177, IRD-CIRAD, CIRAD TA A-17/G, Campus International de Baillarguet, Montpellier Cedex 5, France - Center for Research on Filariasis and other Tropical Diseases (CRFILMT), PO Box 5797 Yaoundé, Cameroon - University of Yaoundé I, Faculty of Science, PO Box 812, Yaoundé, Cameroon
| | - Pascal Lutumba
- Institut national de recherche biomédicale Kinshasa, Avenue de la démocratie N°5345, Gombe, Kinshasa, Democratic Republic of Congo - Department of Tropical Medicine, University of Kinshasa, B.P. 127 Kinshasa XI, Democratic Republic of Congo
| | - Flobert Njiokou
- Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé I, PO Box 812 Yaoundé, Cameroon
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14
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Kanté ST, Melachio T, Ofon E, Njiokou F, Simo G. Detection of Wolbachia and different trypanosome species in Glossina palpalis palpalis populations from three sleeping sickness foci of southern Cameroon. Parasit Vectors 2018; 11:630. [PMID: 30541614 PMCID: PMC6292098 DOI: 10.1186/s13071-018-3229-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 11/23/2018] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND African trypanosomiases are caused by trypanosomes that are cyclically transmitted by tsetse. Investigations aiming to generate knowledge on the bacterial fauna of tsetse have revealed distinct symbiotic microorganisms. Furthermore, studies addressing the tripartite association between trypanosomes-tsetse-symbionts relationship have so far been contradictory. Most studies included Sodalis glossinudius and, consequently, the association involving Wolbachia is poorly understood. Understanding the vectorial competence of tsetse requires decrypting these tripartite associations. In this study, we identified Wolbachia and trypanosomes in Glossina palpalis palpalis from three human African trypanosomiasis (HAT) foci in southern Cameroon. METHODS Tsetse flies were captured with pyramidal traps in the Bipindi, Campo and Fontem HAT foci. After morphological identification, DNA was extracted from whole tsetse flies and Wolbachia and trypanosomes were identified by PCR using different trypanosome-specific primers and two Wolbachia-specific primers (Wolbachia surface protein and 16S rRNA genes). Statistical analyses were performed to compare the trypanosome and Wolbachia infection rates between villages and different foci and to look for an association between these microorganisms. RESULTS From a total of 2122 tsetse flies, 790 G. p. palpalis were analyzed. About 25.32% of flies hosted Wolbachia and 31.84% of non-teneral flies were infected by at least one trypanosome species. There was no significant difference between the global Wolbachia prevalence revealed by the two markers while some differences were observed between HAT foci. From 248 G. p. palpalis with trypanosome infections, 62.90% were with T. vivax, 34.68% with T. congolense forest, 16.13% with T. brucei (s.l.) and 2.42% with T. congolense savannah. Of all trypanosome-infected flies, 29.84% hosted Wolbachia and no association was observed between Wolbachia and trypanosome co-infections. CONCLUSIONS This study revealed differences in the prevalence of Wolbachia and trypanosomes in G. p. palpalis according to HAT foci. The use of only one marker has underestimated the prevalence of Wolbachia, thus more markers in subsequent studies may improve its detection. The presence of Wolbachia seems to have no impact on the establishment of trypanosomes in G. p. palpalis. The tripartite association between tsetse, Wolbachia and trypanosomes varies according to studied areas. Studies aiming to evaluate the genetic polymorphism of Wolbachia and its density in tsetse flies could help to better understand this association.
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Affiliation(s)
- Sartrien Tagueu Kanté
- Molecular Parasitology and Entomology Unit (MPEU), Department of Biochemistry, Faculty of Science, University of Dschang, PO Box 67, Dschang, Cameroon
| | - Trésor Melachio
- Laboratory of Parasitology and Ecology, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon
| | - Elvis Ofon
- Molecular Parasitology and Entomology Unit (MPEU), Department of Biochemistry, Faculty of Science, University of Dschang, PO Box 67, Dschang, Cameroon
| | - Flobert Njiokou
- Laboratory of Parasitology and Ecology, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon
| | - Gustave Simo
- Molecular Parasitology and Entomology Unit (MPEU), Department of Biochemistry, Faculty of Science, University of Dschang, PO Box 67, Dschang, Cameroon
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15
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Kariithi HM, Meki IK, Schneider DI, De Vooght L, Khamis FM, Geiger A, Demirbaş-Uzel G, Vlak JM, iNCE IA, Kelm S, Njiokou F, Wamwiri FN, Malele II, Weiss BL, Abd-Alla AMM. Enhancing vector refractoriness to trypanosome infection: achievements, challenges and perspectives. BMC Microbiol 2018; 18:179. [PMID: 30470182 PMCID: PMC6251094 DOI: 10.1186/s12866-018-1280-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
With the absence of effective prophylactic vaccines and drugs against African trypanosomosis, control of this group of zoonotic neglected tropical diseases depends the control of the tsetse fly vector. When applied in an area-wide insect pest management approach, the sterile insect technique (SIT) is effective in eliminating single tsetse species from isolated populations. The need to enhance the effectiveness of SIT led to the concept of investigating tsetse-trypanosome interactions by a consortium of researchers in a five-year (2013-2018) Coordinated Research Project (CRP) organized by the Joint Division of FAO/IAEA. The goal of this CRP was to elucidate tsetse-symbiome-pathogen molecular interactions to improve SIT and SIT-compatible interventions for trypanosomoses control by enhancing vector refractoriness. This would allow extension of SIT into areas with potential disease transmission. This paper highlights the CRP's major achievements and discusses the science-based perspectives for successful mitigation or eradication of African trypanosomosis.
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Affiliation(s)
- Henry M Kariithi
- Biotechnology Research Institute, Kenya Agricultural & Livestock Research Organization, P.O Box 57811, 00200, Kaptagat Rd, Loresho, Nairobi, Kenya
| | - Irene K Meki
- Insect Pest Control Laboratory, FAO/IAEA Agriculture & Biotechnology Laboratory, IAEA Laboratories Seibersdorf, A-2444 Seibersdorf, Austria
- Laboratory of Virology, Wageningen University and Research, Wageningen, 6708 PB The Netherlands
| | - Daniela I Schneider
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, 60 College Street, New Haven, CT 06510 USA
| | - Linda De Vooght
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Fathiya M Khamis
- International Centre of Insect Physiology and Ecology, P.O. Box 30772, 00100, Nairobi, Kenya
| | - Anne Geiger
- INTERTRYP, Institut de Recherche pour le Développement, University of Montpellier, Montpellier, France
| | - Guler Demirbaş-Uzel
- Insect Pest Control Laboratory, FAO/IAEA Agriculture & Biotechnology Laboratory, IAEA Laboratories Seibersdorf, A-2444 Seibersdorf, Austria
| | - Just M Vlak
- Laboratory of Virology, Wageningen University and Research, Wageningen, 6708 PB The Netherlands
| | - ikbal Agah iNCE
- Institute of Chemical, Environmental & Biological Engineering, Research Area Biochemical Technology, Vienna University of Technology, Gumpendorfer Straße 1a, 1060 Vienna, Austria
| | - Sorge Kelm
- Department of Medical Microbiology, Acıbadem Mehmet Ali Aydınlar University, School of Medicine, 34752, Ataşehir, Istanbul, Turkey
| | - Flobert Njiokou
- Centre for Biomolecular Interactions Bremen, Faculty for Biology & Chemistry, Universität Bremen, Bibliothekstraße 1, 28359 Bremen, Germany
| | - Florence N Wamwiri
- Laboratory of Parasitology and Ecology, Faculty of Sciences, Department of Animal Biology and Physiology, University of Yaoundé 1, Yaoundé, BP 812 Cameroon
| | - Imna I Malele
- Trypanosomiasis Research Centre, Kenya Agricultural & Livestock Research Organization, P.O. Box 362-00902, Kikuyu, Kenya
| | - Brian L Weiss
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, 60 College Street, New Haven, CT 06510 USA
| | - Adly M M Abd-Alla
- Molecular Department, Vector and Vector Borne Diseases Institute, Tanzania Veterinary Laboratory Agency, Majani Mapana, Off Korogwe Road, Box, 1026 Tanga, Tanzania
- Insect Pest Control Laboratory, FAO/IAEA Agriculture & Biotechnology Laboratory, IAEA Laboratories Seibersdorf, A-2444 Seibersdorf, Austria
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16
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Okeyo WA, Saarman NP, Bateta R, Dion K, Mengual M, Mireji PO, Ouma C, Okoth S, Murilla G, Aksoy S, Caccone A. Genetic Differentiation of Glossina pallidipes Tsetse Flies in Southern Kenya. Am J Trop Med Hyg 2018; 99:945-953. [PMID: 30105964 PMCID: PMC6159567 DOI: 10.4269/ajtmh.18-0154] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 06/15/2018] [Indexed: 11/07/2022] Open
Abstract
The tsetse fly Glossina pallidipes, the major vector of the parasite that causes animal African trypanosomiasis in Kenya, has been subject to intense control measures with only limited success. The G. pallidipes population dynamics and dispersal patterns that underlie limited success in vector control campaigns remain unresolved, and knowledge on genetic connectivity can provide insights, and thereby improve control and monitoring efforts. We therefore investigated the population structure and estimated migration and demographic parameters in G. pallidipes using genotypic data from 11 microsatellite loci scored in 250 tsetse flies collected from eight localities in Kenya. Clustering analysis identified two genetically distinct eastern and western clusters (mean between-cluster F ST = 0.202) separated by the Great Rift Valley. We also found evidence of admixture and migration between the eastern and western clusters, isolation by distance, and a widespread signal of inbreeding. We detected differences in population dynamics and dispersal patterns between the western and eastern clusters. These included lower genetic diversity (allelic richness; 7.48 versus 10.99), higher relatedness (percent related individuals; 21.4% versus 9.1%), and greater genetic differentiation (mean within-cluster F ST; 0.183 versus 0.018) in the western than the eastern cluster. Findings are consistent with the presence of smaller, less well-connected populations in Western relative to eastern Kenya. These data suggest that recent anthropogenic influences such as land use changes and vector control programs have influenced population dynamics in G. pallidipes in Kenya, and that vector control efforts should include some region-specific strategies to effectively control this disease vector.
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Affiliation(s)
- Winnie A. Okeyo
- Department of Biomedical Sciences and Technology, School of Public Health and Community Development, Maseno University, Kisumu, Kenya
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Nairobi, Kenya
- Yale School of Public Health, Yale University, New Haven, Connecticut
| | - Norah P. Saarman
- Department of Ecology & Evolutionary Biology, Yale University, New Haven, Connecticut
| | - Rosemary Bateta
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Nairobi, Kenya
| | - Kirstin Dion
- Department of Ecology & Evolutionary Biology, Yale University, New Haven, Connecticut
| | - Michael Mengual
- Department of Ecology & Evolutionary Biology, Yale University, New Haven, Connecticut
| | - Paul O. Mireji
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Nairobi, Kenya
- Yale School of Public Health, Yale University, New Haven, Connecticut
- Center for Geographic Medicine Research Coast, Kenya Medical Research Institute, Kilifi, Kenya
| | - Collins Ouma
- Department of Biomedical Sciences and Technology, School of Public Health and Community Development, Maseno University, Kisumu, Kenya
| | - Sylvance Okoth
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Nairobi, Kenya
| | - Grace Murilla
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Nairobi, Kenya
- Yale School of Public Health, Yale University, New Haven, Connecticut
| | - Serap Aksoy
- Yale School of Public Health, Yale University, New Haven, Connecticut
| | - Adalgisa Caccone
- Yale School of Public Health, Yale University, New Haven, Connecticut
- Department of Ecology & Evolutionary Biology, Yale University, New Haven, Connecticut
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17
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Krafsur ES, Maudlin I. Tsetse fly evolution, genetics and the trypanosomiases - A review. INFECTION GENETICS AND EVOLUTION 2018; 64:185-206. [PMID: 29885477 DOI: 10.1016/j.meegid.2018.05.033] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 05/30/2018] [Accepted: 05/31/2018] [Indexed: 01/27/2023]
Abstract
This reviews work published since 2007. Relative efforts devoted to the agents of African trypanosomiasis and their tsetse fly vectors are given by the numbers of PubMed accessions. In the last 10 years PubMed citations number 3457 for Trypanosoma brucei and 769 for Glossina. The development of simple sequence repeats and single nucleotide polymorphisms afford much higher resolution of Glossina and Trypanosoma population structures than heretofore. Even greater resolution is offered by partial and whole genome sequencing. Reproduction in T. brucei sensu lato is principally clonal although genetic recombination in tsetse salivary glands has been demonstrated in T. b. brucei and T. b. rhodesiense but not in T. b. gambiense. In the past decade most genetic attention was given to the chief human African trypanosomiasis vectors in subgenus Nemorhina e.g., Glossina f. fuscipes, G. p. palpalis, and G. p. gambiense. The chief interest in Nemorhina population genetics seemed to be finding vector populations sufficiently isolated to enable efficient and long-lasting suppression. To this end estimates were made of gene flow, derived from FST and its analogues, and Ne, the size of a hypothetical population equivalent to that under study. Genetic drift was greater, gene flow and Ne typically lesser in savannah inhabiting tsetse (subgenus Glossina) than in riverine forms (Nemorhina). Population stabilities were examined by sequential sampling and genotypic analysis of nuclear and mitochondrial genomes in both groups and found to be stable. Gene frequencies estimated in sequential samplings differed by drift and allowed estimates of effective population numbers that were greater for Nemorhina spp than Glossina spp. Prospects are examined of genetic methods of vector control. The tsetse long generation time (c. 50 d) is a major contraindication to any suggested genetic method of tsetse population manipulation. Ecological and modelling research convincingly show that conventional methods of targeted insecticide applications and traps/targets can achieve cost-effective reduction in tsetse densities.
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Affiliation(s)
- E S Krafsur
- Department of Entomology, Iowa State University, Ames, IA 50011, USA.
| | - Ian Maudlin
- School of Biomedical Sciences, The University of Edinburgh, Scotland, UK
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18
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Saarman N, Burak M, Opiro R, Hyseni C, Echodu R, Dion K, Opiyo EA, Dunn AW, Amatulli G, Aksoy S, Caccone A. A spatial genetics approach to inform vector control of tsetse flies ( Glossina fuscipes fuscipes) in Northern Uganda. Ecol Evol 2018; 8:5336-5354. [PMID: 29938057 PMCID: PMC6010828 DOI: 10.1002/ece3.4050] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 02/22/2018] [Accepted: 02/23/2018] [Indexed: 11/09/2022] Open
Abstract
Tsetse flies (genus Glossina) are the only vector for the parasitic trypanosomes responsible for sleeping sickness and nagana across sub-Saharan Africa. In Uganda, the tsetse fly Glossina fuscipes fuscipes is responsible for transmission of the parasite in 90% of sleeping sickness cases, and co-occurrence of both forms of human-infective trypanosomes makes vector control a priority. We use population genetic data from 38 samples from northern Uganda in a novel methodological pipeline that integrates genetic data, remotely sensed environmental data, and hundreds of field-survey observations. This methodological pipeline identifies isolated habitat by first identifying environmental parameters correlated with genetic differentiation, second, predicting spatial connectivity using field-survey observations and the most predictive environmental parameter(s), and third, overlaying the connectivity surface onto a habitat suitability map. Results from this pipeline indicated that net photosynthesis was the strongest predictor of genetic differentiation in G. f. fuscipes in northern Uganda. The resulting connectivity surface identified a large area of well-connected habitat in northwestern Uganda, and twenty-four isolated patches on the northeastern margin of the G. f. fuscipes distribution. We tested this novel methodological pipeline by completing an ad hoc sample and genetic screen of G. f. fuscipes samples from a model-predicted isolated patch, and evaluated whether the ad hoc sample was in fact as genetically isolated as predicted. Results indicated that genetic isolation of the ad hoc sample was as genetically isolated as predicted, with differentiation well above estimates made in samples from within well-connected habitat separated by similar geographic distances. This work has important practical implications for the control of tsetse and other disease vectors, because it provides a way to identify isolated populations where it will be safer and easier to implement vector control and that should be prioritized as study sites during the development and improvement of vector control methods.
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Affiliation(s)
- Norah Saarman
- Department of Ecology and Evolutionary BiologyYale UniversityNew HavenConnecticut
| | - Mary Burak
- Department of Ecology and Evolutionary BiologyYale UniversityNew HavenConnecticut
| | - Robert Opiro
- Department of BiologyFaculty of ScienceGulu UniversityGuluLaroo DivisionUganda
| | - Chaz Hyseni
- Department of BiologyUniversity of MississippiOxfordMassachusetts
| | - Richard Echodu
- Department of BiologyFaculty of ScienceGulu UniversityGuluLaroo DivisionUganda
| | - Kirstin Dion
- Department of Ecology and Evolutionary BiologyYale UniversityNew HavenConnecticut
| | - Elizabeth A. Opiyo
- Department of BiologyFaculty of ScienceGulu UniversityGuluLaroo DivisionUganda
| | - Augustine W. Dunn
- Division of Genetics and GenomicsBoston Children's HospitalBostonMassachusetts
| | - Giuseppe Amatulli
- Department of GeoComputation and Spatial ScienceYale School of Forestry and Environmental StudiesNew HavenConnecticut
| | - Serap Aksoy
- Department of Epidemiology of Microbial DiseasesYale School of Public HealthNew HavenConnecticut
| | - Adalgisa Caccone
- Department of Ecology and Evolutionary BiologyYale UniversityNew HavenConnecticut
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19
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Jacob F, Melachio TT, Njitchouang GR, Gimonneau G, Njiokou F, Abate L, Christen R, Reveillaud J, Geiger A. Intestinal Bacterial Communities of Trypanosome-Infected and Uninfected Glossina palpalis palpalis from Three Human African Trypanomiasis Foci in Cameroon. Front Microbiol 2017; 8:1464. [PMID: 28824591 PMCID: PMC5541443 DOI: 10.3389/fmicb.2017.01464] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Accepted: 07/20/2017] [Indexed: 11/27/2022] Open
Abstract
Glossina sp. the tsetse fly that transmits trypanosomes causing the Human or the Animal African Trypanosomiasis (HAT or AAT) can harbor symbiotic bacteria that are known to play a crucial role in the fly's vector competence. We hypothesized that other bacteria could be present, and that some of them could also influence the fly's vector competence. In this context the objectives of our work were: (a) to characterize the bacteria that compose the G. palpalis palpalis midgut bacteriome, (b) to evidence possible bacterial community differences between trypanosome-infected and non-infected fly individuals from a given AAT and HAT focus or from different foci using barcoded Illumina sequencing of the hypervariable V3-V4 region of the 16S rRNA gene. Forty G. p. palpalis flies, either infected by Trypanosoma congolense or uninfected were sampled from three trypanosomiasis foci in Cameroon. A total of 143 OTUs were detected in the midgut samples. Most taxa were identified at the genus level, nearly 50% at the species level; they belonged to 83 genera principally within the phyla Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria. Prominent representatives included Wigglesworthia (the fly's obligate symbiont), Serratia, and Enterobacter hormaechei. Wolbachia was identified for the first time in G. p. palpalis. The average number of bacterial species per tsetse sample was not significantly different regarding the fly infection status, and the hierarchical analysis based on the differences in bacterial community structure did not provide a clear clustering between infected and non-infected flies. Finally, the most important result was the evidence of the overall very large diversity of intestinal bacteria which, except for Wigglesworthia, were unevenly distributed over the sampled flies regardless of their geographic origin and their trypanosome infection status.
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Affiliation(s)
- Franck Jacob
- UMR INTERTRYP, Institut de Recherche pour le Développement-CIRAD, CIRAD TA A-17/GMontpellier, France
| | - Trésor T Melachio
- Parasitology and Ecology Laboratory, Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde 1Yaounde, Cameroon
| | - Guy R Njitchouang
- Parasitology and Ecology Laboratory, Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde 1Yaounde, Cameroon
| | - Geoffrey Gimonneau
- UMR INTERTRYP, Institut de Recherche pour le Développement-CIRAD, CIRAD TA A-17/GMontpellier, France
| | - Flobert Njiokou
- Parasitology and Ecology Laboratory, Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde 1Yaounde, Cameroon
| | - Luc Abate
- UMR MIVEGEC, Institut de Recherche pour le Développement 224-Centre National de la Recherche Scientifique 5290Montpellier, France
| | - Richard Christen
- UMR 7138, Systématique Adaptation Evolution, Université de Nice-Sophia AntipolisNice, France
| | - Julie Reveillaud
- Institut National de la Recherche Agronomique, UMR 1309 ASTREMontpellier, France.,CIRAD, UMR ASTREMontpellier, France
| | - Anne Geiger
- UMR INTERTRYP, Institut de Recherche pour le Développement-CIRAD, CIRAD TA A-17/GMontpellier, France
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20
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Genetic diversity and population structure of the tsetse fly Glossina fuscipes fuscipes (Diptera: Glossinidae) in Northern Uganda: Implications for vector control. PLoS Negl Trop Dis 2017; 11:e0005485. [PMID: 28453513 PMCID: PMC5425221 DOI: 10.1371/journal.pntd.0005485] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 05/10/2017] [Accepted: 03/12/2017] [Indexed: 11/19/2022] Open
Abstract
Uganda is the only country where the chronic and acute forms of human African Trypanosomiasis (HAT) or sleeping sickness both occur and are separated by < 100 km in areas north of Lake Kyoga. In Uganda, Glossina fuscipes fuscipes is the main vector of the Trypanosoma parasites responsible for these diseases as well for the animal African Trypanosomiasis (AAT), or Nagana. We used highly polymorphic microsatellite loci and a mitochondrial DNA (mtDNA) marker to provide fine scale spatial resolution of genetic structure of G. f. fuscipes from 42 sampling sites from the northern region of Uganda where a merger of the two disease belts is feared. Based on microsatellite analyses, we found that G. f. fuscipes in northern Uganda are structured into three distinct genetic clusters with varying degrees of interconnectivity among them. Based on genetic assignment and spatial location, we grouped the sampling sites into four genetic units corresponding to northwestern Uganda in the Albert Nile drainage, northeastern Uganda in the Lake Kyoga drainage, western Uganda in the Victoria Nile drainage, and a transition zone between the two northern genetic clusters characterized by high level of genetic admixture. An analysis using HYBRIDLAB supported a hybrid swarm model as most consistent with tsetse genotypes in these admixed samples. Results of mtDNA analyses revealed the presence of 30 haplotypes representing three main haplogroups, whose location broadly overlaps with the microsatellite defined clusters. Migration analyses based on microsatellites point to moderate migration among the northern units located in the Albert Nile, Achwa River, Okole River, and Lake Kyoga drainages, but not between the northern units and the Victoria Nile drainage in the west. Effective population size estimates were variable with low to moderate sizes in most populations and with evidence of recent population bottlenecks, especially in the northeast unit of the Lake Kyoga drainage. Our microsatellite and mtDNA based analyses indicate that G. f. fuscipes movement along the Achwa and Okole rivers may facilitate northwest expansion of the Rhodesiense disease belt in Uganda. We identified tsetse migration corridors and recommend a rolling carpet approach from south of Lake Kyoga northward to minimize disease dispersal and prevent vector re-colonization. Additionally, our findings highlight the need for continuing tsetse monitoring efforts during and after control. Northern Uganda is an epidemiologically important region affected by human African trypanosomiasis (HAT) because it harbors both forms of the HAT disease (T. b. gambiense and T. b. rhodesiense). The geographic location of this region creates the risk that these distinct foci could merge, which would complicate diagnosis and treatment, and may result in recombination between the two parasite strains with as yet unknown consequences. Both strains require a tsetse fly vector for transmission, and in Uganda, G. f. fuscipes is the major vector of HAT. Controlling the vector remains one of the most effective strategies for controlling trypanosome parasites. However, vector control efforts may not be sustainable in terms of long term reduction in G. f. fuscipes populations due to population rebounds. Population genetics data can allow us to determine the likely source of population rebounds and to establish a more robust control strategy. In this study, we build on a previous broad spatial survey of G. f. fuscipes genetic structure in Uganda by adding more than 30 novel sampling sites that are strategically spaced across a region of northern Uganda that, for historical and political reasons, was severely understudied and faces particularly high disease risk. We identify natural population breaks, migration corridors and a hybrid zone with evidence of free interbreeding of G. f. fuscipes across the geographic region that spans the two HAT disease foci. We also find evidence of low effective population sizes and population bottlenecks in some areas that have been subjects of past control but remain regions of high tsetse density, which stresses the risk of population rebounds if monitoring is not explicitly incorporated into the control strategy. We use these results to make suggestions that will enhance the design and implementation of control activities in northern Uganda.
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21
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Aksoy S, Buscher P, Lehane M, Solano P, Van Den Abbeele J. Human African trypanosomiasis control: Achievements and challenges. PLoS Negl Trop Dis 2017; 11:e0005454. [PMID: 28426685 PMCID: PMC5398477 DOI: 10.1371/journal.pntd.0005454] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Sleeping sickness, also known as human African trypanosomiasis (HAT), is a neglected disease that impacts 70 million people living in 1.55 million km2 in sub-Saharan Africa. Since the beginning of the 20th century, there have been multiple HAT epidemics in sub-Saharan Africa, with the most recent epidemic in the 1990s resulting in about half a million HAT cases reported between 1990 and 2015. Here we review the status of HAT disease at the current time and the toolbox available for its control. We also highlight future opportunities under development towards novel or improved interventions.
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Affiliation(s)
- Serap Aksoy
- Department of Epidemiology of Microbial Diseases, School of Public Health, Yale University, New Haven, Connecticut, United States of America
- * E-mail:
| | - Phillipe Buscher
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Mike Lehane
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Philippe Solano
- Institut de Recherche pour le Développement (IRD), Montpellier, France
| | - Jan Van Den Abbeele
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
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22
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Patterns of Genome-Wide Variation in Glossina fuscipes fuscipes Tsetse Flies from Uganda. G3-GENES GENOMES GENETICS 2016; 6:1573-84. [PMID: 27172181 PMCID: PMC4889654 DOI: 10.1534/g3.116.027235] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The tsetse fly Glossina fuscipes fuscipes (Gff) is the insect vector of the two forms of Human African Trypanosomiasis (HAT) that exist in Uganda. Understanding Gff population dynamics, and the underlying genetics of epidemiologically relevant phenotypes is key to reducing disease transmission. Using ddRAD sequence technology, complemented with whole-genome sequencing, we developed a panel of ∼73,000 single-nucleotide polymorphisms (SNPs) distributed across the Gff genome that can be used for population genomics and to perform genome-wide-association studies. We used these markers to estimate genomic patterns of linkage disequilibrium (LD) in Gff, and used the information, in combination with outlier-locus detection tests, to identify candidate regions of the genome under selection. LD in individual populations decays to half of its maximum value (r(2) max/2) between 1359 and 2429 bp. The overall LD estimated for the species reaches r(2) max/2 at 708 bp, an order of magnitude slower than in Drosophila Using 53 infected (Trypanosoma spp.) and uninfected flies from four genetically distinct Ugandan populations adapted to different environmental conditions, we were able to identify SNPs associated with the infection status of the fly and local environmental adaptation. The extent of LD in Gff likely facilitated the detection of loci under selection, despite the small sample size. Furthermore, it is probable that LD in the regions identified is much higher than the average genomic LD due to strong selection. Our results show that even modest sample sizes can reveal significant genetic associations in this species, which has implications for future studies given the difficulties of collecting field specimens with contrasting phenotypes for association analysis.
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23
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Opiro R, Saarman NP, Echodu R, Opiyo EA, Dion K, Halyard A, Aksoy S, Caccone A. Evidence of temporal stability in allelic and mitochondrial haplotype diversity in populations of Glossina fuscipes fuscipes (Diptera: Glossinidae) in northern Uganda. Parasit Vectors 2016; 9:258. [PMID: 27141947 PMCID: PMC4855780 DOI: 10.1186/s13071-016-1522-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 04/20/2016] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Glossina fuscipes fuscipes is a tsetse species of high economic importance in Uganda where it is responsible for transmitting animal African trypanosomiasis (AAT) and both the chronic and acute forms of human African trypanosomiasis (HAT). We used genotype data from 17 microsatellites and a mitochondrial DNA marker to assess temporal changes in gene frequency for samples collected between the periods ranging from 2008 to 2014 in nine localities spanning regions known to harbor the two forms of HAT in northern Uganda. RESULTS Our findings suggest that the majority of the studied populations in both HAT foci are genetically stable across the time span sampled. Pairwise estimates of differentiation using standardized FST and Jost's DEST between time points sampled for each site were generally low and ranged between 0.0019 and 0.1312 for both sets of indices. We observed the highest values of FST and DEST between time points sampled from Kitgum (KT), Karuma (KR), Moyo (MY) and Pader (PD), and the possible reasons for this are discussed. Effective population size (Ne) estimates using Waple's temporal method ranged from 103 (95% CI: 73-138) in Kitgum to 962 (95% CI: 669-1309) in Oculoi (OC). Additionally, evidence of a bottleneck event was detected in only one population at one time point sampled; Aminakwach (AM-27) from December 2014 (P < 0.03889). CONCLUSION Findings suggest general temporal stability of tsetse vectors in foci of both forms of HAT in northern Uganda. Genetic stability and the moderate effective population sizes imply that a re-emergence of vectors from local residual populations missed by control efforts is an important risk. This underscores the need for more sensitive sampling and monitoring to detect residual populations following control activities.
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Affiliation(s)
- Robert Opiro
- Department of Biology, Faculty of Science, Gulu University, Gulu, Uganda.
| | - Norah P Saarman
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, USA
| | - Richard Echodu
- Department of Biology, Faculty of Science, Gulu University, Gulu, Uganda
| | - Elizabeth A Opiyo
- Department of Biology, Faculty of Science, Gulu University, Gulu, Uganda
| | - Kirstin Dion
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, USA
| | - Alexis Halyard
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, USA
| | - Serap Aksoy
- Yale School of Public Health, Yale University, New Haven, CT, USA
| | - Adalgisa Caccone
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, USA
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24
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Richardson JB, Evans B, Pyana PP, Van Reet N, Sistrom M, Büscher P, Aksoy S, Caccone A. Whole genome sequencing shows sleeping sickness relapse is due to parasite regrowth and not reinfection. Evol Appl 2016; 9:381-93. [PMID: 26834831 PMCID: PMC4721075 DOI: 10.1111/eva.12338] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2015] [Accepted: 09/29/2015] [Indexed: 11/27/2022] Open
Abstract
The trypanosome Trypanosoma brucei gambiense (Tbg) is a cause of human African trypanosomiasis (HAT) endemic to many parts of sub-Saharan Africa. The disease is almost invariably fatal if untreated and there is no vaccine, which makes monitoring and managing drug resistance highly relevant. A recent study of HAT cases from the Democratic Republic of the Congo reported a high incidence of relapses in patients treated with melarsoprol. Of the 19 Tbg strains isolated from patients enrolled in this study, four pairs were obtained from the same patient before treatment and after relapse. We used whole genome sequencing to investigate whether these patients were infected with a new strain, or if the original strain had regrown to pathogenic levels. Clustering analysis of 5938 single nucleotide polymorphisms supports the hypothesis of regrowth of the original strain, as we found that strains isolated before and after treatment from the same patient were more similar to each other than to other isolates. We also identified 23 novel genes that could affect melarsoprol sensitivity, representing a promising new set of targets for future functional studies. This work exemplifies the utility of using evolutionary approaches to provide novel insights and tools for disease control.
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Affiliation(s)
- Joshua B Richardson
- Department of Ecology and Evolutionary Biology Yale University New Haven CT USA
| | - Benjamin Evans
- Department of Ecology and Evolutionary Biology Yale University New Haven CT USA
| | - Patient P Pyana
- Department de Parasitologie Institut National de Recherche Biomedicale Kinshasa Gombe Democratic Republic of the Congo
| | - Nick Van Reet
- Department of Biomedical Sciences Institute of Tropical Medicine Antwerp Belgium
| | - Mark Sistrom
- School of Natural Sciences University of California Merced Merced CA USA
| | - Philippe Büscher
- Department of Biomedical Sciences Institute of Tropical Medicine Antwerp Belgium
| | - Serap Aksoy
- Department of Epidemiology and Public Health Yale School of Public Health New Haven CT USA
| | - Adalgisa Caccone
- Department of Ecology and Evolutionary Biology Yale University New Haven CT USA
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25
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Pandey A, Atkins KE, Bucheton B, Camara M, Aksoy S, Galvani AP, Ndeffo-Mbah ML. Evaluating long-term effectiveness of sleeping sickness control measures in Guinea. Parasit Vectors 2015; 8:550. [PMID: 26490037 PMCID: PMC4618537 DOI: 10.1186/s13071-015-1121-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2015] [Accepted: 09/29/2015] [Indexed: 11/11/2022] Open
Abstract
Background Human African Trypanosomiasis threatens human health across Africa. The subspecies T.b. gambiense is responsible for the vast majority of reported HAT cases. Over the past decade, expanded control efforts accomplished a substantial reduction in HAT transmission, spurring the WHO to include Gambian HAT on its roadmap for 2020 elimination. To inform the implementation of this elimination goal, we evaluated the likelihood that current control interventions will achieve the 2020 target in Boffa prefecture in Guinea, which has one of the highest prevalences for HAT in the country, and where vector control measures have been implemented in combination with the traditional screen and treat strategy. Methods We developed a three-species mathematical model of HAT and used a Bayesian melding approach to calibrate the model to epidemiological and entomological data from Boffa. From the calibrated model, we generated the probabilistic predictions regarding the likelihood that the current HAT control programs could achieve elimination by 2020 in Boffa. Results Our model projections indicate that if annual vector control is implemented in combination with annual or biennial active case detection and treatment, the probability of eliminating HAT as public health problem in Boffa by 2020 is over 90%. Annual implementation of vector control alone has a significant impact but a decreased chance of reaching the objective (77%). However, if the ongoing control efforts are interrupted, HAT will continue to remain a public health problem. In the presence of a non-human animal transmission reservoir, intervention strategies must be maintained at high coverage, even after 2020 elimination, to prevent HAT reemerging as a public health problem. Conclusions Complementing active screening and treatment with vector control has the potential to achieve the elimination target before 2020 in the Boffa focus. However, surveillance must continue after elimination to prevent reemergence. Electronic supplementary material The online version of this article (doi:10.1186/s13071-015-1121-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Abhishek Pandey
- Center for Infectious Disease Modeling and Analysis, Yale School of Public Health, New Haven, CT, 06510, USA.,Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, 06510, USA
| | - Katherine E Atkins
- HAT National Control Program, Ministry of Health, Conakry, Republic of Guinea.
| | - Bruno Bucheton
- HAT National Control Program, Ministry of Health, Conakry, Republic of Guinea.,UMR INTERTRYP IRD/CIRAD, TA A 17/G, Campus International de Baillarguet, 34398, Montpellier, cedex 5, France
| | - Mamadou Camara
- HAT National Control Program, Ministry of Health, Conakry, Republic of Guinea.
| | - Serap Aksoy
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, 06510, USA
| | - Alison P Galvani
- Center for Infectious Disease Modeling and Analysis, Yale School of Public Health, New Haven, CT, 06510, USA.,Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, 06510, USA
| | - Martial L Ndeffo-Mbah
- Center for Infectious Disease Modeling and Analysis, Yale School of Public Health, New Haven, CT, 06510, USA.,Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, 06510, USA
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26
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Bonnet J, Boudot C, Courtioux B. Overview of the Diagnostic Methods Used in the Field for Human African Trypanosomiasis: What Could Change in the Next Years? BIOMED RESEARCH INTERNATIONAL 2015; 2015:583262. [PMID: 26504815 PMCID: PMC4609347 DOI: 10.1155/2015/583262] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 06/19/2015] [Accepted: 07/02/2015] [Indexed: 11/18/2022]
Abstract
Sleeping sickness is a parasitic infection caused by two species of trypanosomes (Trypanosoma brucei gambiense and rhodesiense), transmitted by the tsetse fly. The disease eventually affects the central nervous system, resulting in severe neurological symptoms. Without treatment, death is inevitable. During the first stage of the disease, infected patients are mildly symptomatic and early detection of infection allows safer treatment (administered on an outpatient basis) which can avoid death; routine screening of the exposed population is necessary, especially in areas of high endemicity. The current therapeutic treatment of this disease, especially in stage 2, can cause complications and requires a clinical surveillance for several days. A good stage diagnosis of the disease is the cornerstone for delivering the adequate treatment. The task faced by the medical personnel is further complicated by the lack of support from local health infrastructure, which is at best weak, but often nonexistent. Therefore it is crucial to look for new more efficient technics for the diagnosis of stage which are also best suited to use in the field, in areas not possessing high-level health facilities. This review, after an overview of the disease, summarizes the current diagnosis procedures and presents the advances in the field.
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Affiliation(s)
- Julien Bonnet
- INSERM, U1094, Tropical Neuroepidemiology, Limoges, France
- UMR_S 1094, Tropical Neuroepidemiology, Institute of Neuroepidemiology and Tropical Neurology, Université de Limoges, CNRS FR 3503 GEIST, 87000 Limoges, France
| | - Clotilde Boudot
- INSERM, U1094, Tropical Neuroepidemiology, Limoges, France
- UMR_S 1094, Tropical Neuroepidemiology, Institute of Neuroepidemiology and Tropical Neurology, Université de Limoges, CNRS FR 3503 GEIST, 87000 Limoges, France
| | - Bertrand Courtioux
- INSERM, U1094, Tropical Neuroepidemiology, Limoges, France
- UMR_S 1094, Tropical Neuroepidemiology, Institute of Neuroepidemiology and Tropical Neurology, Université de Limoges, CNRS FR 3503 GEIST, 87000 Limoges, France
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McAllaster MR, Ikeda KN, Lozano-Núñez A, Anrather D, Unterwurzacher V, Gossenreiter T, Perry JA, Crickley R, Mercadante CJ, Vaughan S, de Graffenried CL. Proteomic identification of novel cytoskeletal proteins associated with TbPLK, an essential regulator of cell morphogenesis in Trypanosoma brucei. Mol Biol Cell 2015; 26:3013-29. [PMID: 26133384 PMCID: PMC4551316 DOI: 10.1091/mbc.e15-04-0219] [Citation(s) in RCA: 63] [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: 04/15/2015] [Revised: 06/16/2015] [Accepted: 06/24/2015] [Indexed: 01/06/2023] Open
Abstract
Trypanosoma brucei is the causative agent of African sleeping sickness, a devastating disease endemic to sub-Saharan Africa with few effective treatment options. The parasite is highly polarized, including a single flagellum that is nucleated at the posterior of the cell and adhered along the cell surface. These features are essential and must be transmitted to the daughter cells during division. Recently we identified the T. brucei homologue of polo-like kinase (TbPLK) as an essential morphogenic regulator. In the present work, we conduct proteomic screens to identify potential TbPLK binding partners and substrates to better understand the molecular mechanisms of kinase function. These screens identify a cohort of proteins, most of which are completely uncharacterized, which localize to key cytoskeletal organelles involved in establishing cell morphology, including the flagella connector, flagellum attachment zone, and bilobe structure. Depletion of these proteins causes substantial changes in cell division, including mispositioning of the kinetoplast, loss of flagellar connection, and prevention of cytokinesis. The proteins identified in these screens provide the foundation for establishing the molecular networks through which TbPLK directs cell morphogenesis in T. brucei.
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Affiliation(s)
- Michael R McAllaster
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI 02912
| | - Kyojiro N Ikeda
- Max F. Perutz Laboratories, Department of Medical Biochemistry, Medical University of Vienna, 1030 Vienna, Austria
| | - Ana Lozano-Núñez
- Max F. Perutz Laboratories, Center for Molecular Biology, University of Vienna, 1030 Vienna, Austria
| | - Dorothea Anrather
- Max F. Perutz Laboratories, Mass Spectrometry Facility, University of Vienna, 1030 Vienna, Austria
| | - Verena Unterwurzacher
- Max F. Perutz Laboratories, Mass Spectrometry Facility, University of Vienna, 1030 Vienna, Austria
| | - Thomas Gossenreiter
- Max F. Perutz Laboratories, Mass Spectrometry Facility, University of Vienna, 1030 Vienna, Austria
| | - Jenna A Perry
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI 02912
| | - Robbie Crickley
- Department of Biological and Medical Sciences, Faculty of Health and Life Science, Oxford Brookes University, Oxford OX3 0BP, United Kingdom
| | - Courtney J Mercadante
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI 02912
| | - Sue Vaughan
- Department of Biological and Medical Sciences, Faculty of Health and Life Science, Oxford Brookes University, Oxford OX3 0BP, United Kingdom
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Kato AB, Hyseni C, Okedi LM, Ouma JO, Aksoy S, Caccone A, Masembe C. Mitochondrial DNA sequence divergence and diversity of Glossina fuscipes fuscipes in the Lake Victoria basin of Uganda: implications for control. Parasit Vectors 2015; 8:385. [PMID: 26197892 PMCID: PMC4511262 DOI: 10.1186/s13071-015-0984-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2015] [Accepted: 07/02/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Glossina fuscipes fuscipes is the main vector of African Trypanosomiasis affecting both humans and livestock in Uganda. The human disease (sleeping sickness) manifests itself in two forms: acute and chronic. The Lake Victoria basin in Uganda has the acute form and a history of tsetse re-emergence despite concerted efforts to control tsetse. The government of Uganda has targeted the basin for tsetse eradication. To provide empirical data for this initiative, we screened tsetse flies from the basin for genetic variation at the mitochondrial DNA cytochrome oxidase II (mtDNA COII) gene with the goal of investigating genetic diversity and gene flow among tsetse, tsetse demographic history; and compare these results with results from a previous study based on microsatellite loci data in the same area. METHODS We collected 429 Gff tsetse fly samples from 14 localities in the entire Ugandan portion of the Lake Victoria coast, covering 40,000 km(2). We performed genetic analyses on them and added data collected for 56 Gff individuals from 4 additional sampling sites in the basin. The 529 pb partial mitochondrial DNA cytochrome oxidase II (mtDNA COII) sequences totaling 485 were analysed for genetic differentiation, structuring and demographic history. The results were compared with findings from a previous study based on microsatellite loci data from the basin. RESULTS The differences within sampling sites explained a significant proportion of the genetic variation. We found three very closely related mtDNA population clusters, which co-occurred in multiple sites. Although Φ ST (0 - 0.592; P < 0.05) and Bayesian analyses suggest some level of weak genetic differentiation, there is no correlation between genetic divergence and geographic distance (r = 0.109, P = 0.185), and demographic tests provide evidence of locality-based demographic history. CONCLUSION The mtDNA data analysed here complement inferences made in a previous study based on microsatellite data. Given the differences in mutation rates, mtDNA afforded a look further back in time than microsatellites and revealed that Gff populations were more connected in the past. Microsatellite data revealed more genetic structuring than mtDNA. The differences in connectedness and structuring over time could be related to vector control efforts. Tsetse re-emergence after control interventions may be due to re-invasions from outside the treated areas, which emphasizes the need for an integrated area-wide tsetse eradication strategy for sustainable removal of the tsetse and trypanosomiasis problem from this area.
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Affiliation(s)
- Agapitus B Kato
- Department of Biological Sciences, College of Natural Sciences, Makerere University, Box 7062, Kampala, Uganda.
| | - Chaz Hyseni
- Department of Biology, University of Mississippi, Oxford, MS, 38677, USA.
| | - Loyce M Okedi
- National Livestock Resources Research Institute, Tororo, Uganda.
| | - Johnson O Ouma
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Kikuyu, Kenya.
| | - Serap Aksoy
- Division of Epidemiology of Microbial Diseases, Yale School of Public Health, Yale University, New Haven, CT, 06520, USA.
| | - Adalgisa Caccone
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, 06520, USA.
| | - Charles Masembe
- Department of Biological Sciences, College of Natural Sciences, Makerere University, Box 7062, Kampala, Uganda.
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Carpi G, Walter KS, Bent SJ, Hoen AG, Diuk-Wasser M, Caccone A. Whole genome capture of vector-borne pathogens from mixed DNA samples: a case study of Borrelia burgdorferi. BMC Genomics 2015; 16:434. [PMID: 26048573 PMCID: PMC4458057 DOI: 10.1186/s12864-015-1634-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 05/18/2015] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND Rapid and accurate retrieval of whole genome sequences of human pathogens from disease vectors or animal reservoirs will enable fine-resolution studies of pathogen epidemiological and evolutionary dynamics. However, next generation sequencing technologies have not yet been fully harnessed for the study of vector-borne and zoonotic pathogens, due to the difficulty of obtaining high-quality pathogen sequence data directly from field specimens with a high ratio of host to pathogen DNA. RESULTS We addressed this challenge by using custom probes for multiplexed hybrid capture to enrich for and sequence 30 Borrelia burgdorferi genomes from field samples of its arthropod vector. Hybrid capture enabled sequencing of nearly the complete genome (~99.5 %) of the Borrelia burgdorferi pathogen with 132-fold coverage, and identification of up to 12,291 single nucleotide polymorphisms per genome. CONCLUSIONS The proprosed culture-independent method enables efficient whole genome capture and sequencing of pathogens directly from arthropod vectors, thus making population genomic study of vector-borne and zoonotic infectious diseases economically feasible and scalable. Furthermore, given the similarities of invertebrate field specimens to other mixed DNA templates characterized by a high ratio of host to pathogen DNA, we discuss the potential applicabilty of hybrid capture for genomic study across diverse study systems.
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Affiliation(s)
- Giovanna Carpi
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, 06520, New Haven, CT, USA.
| | - Katharine S Walter
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, 06520, New Haven, CT, USA.
| | - Stephen J Bent
- Robinson Research Institute, University of Adelaide, 5005, Adelaide, SA, Australia.
| | - Anne Gatewood Hoen
- The Geisel School of Medicine, Dartmouth College, 03755, Hanover, NH, USA.
| | - Maria Diuk-Wasser
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, 06520, New Haven, CT, USA. .,Department of Ecology, Evolution and Environmental Biology, Columbia University, 10027, New York, NY, USA.
| | - Adalgisa Caccone
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, 06520, New Haven, CT, USA. .,Department of Ecology and Evolutionary Biology, Yale University, 06520, New Haven, CT, USA.
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Geiger A, Hamidou Soumana I, Tchicaya B, Rofidal V, Decourcelle M, Santoni V, Hem S. Differential expression of midgut proteins in Trypanosoma brucei gambiense-stimulated vs. non-stimulated Glossina palpalis gambiensis flies. Front Microbiol 2015; 6:444. [PMID: 26029185 PMCID: PMC4428205 DOI: 10.3389/fmicb.2015.00444] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 04/24/2015] [Indexed: 11/13/2022] Open
Abstract
The unicellular pathogenic protozoan Trypanosoma brucei gambiense is responsible for the chronic form of sleeping sickness. This vector-borne disease is transmitted to humans by the tsetse fly of the group Glossina palpalis, including the subspecies G. p. gambiensis, in which the parasite completes its developmental cycle. Sleeping sickness control strategies can therefore target either the human host or the fly vector. Indeed, suppression of one step in the parasite developmental cycle could abolish parasite transmission to humans, with consequences on the spreading of the disease. In order to develop this type of approach, we have identified, at the proteome level, events resulting from the tripartite interaction between the tsetse fly G. p. gambiensis, its microbiome, and the trypanosome. Proteomes were analyzed from four biological replicates of midguts from flies sampled 3 days post-feeding on either a trypanosome-infected (stimulated flies) or a non-infected (non-stimulated flies) bloodmeal. Over 500 proteins were identified in the midguts of flies from both feeding groups, 13 of which were shown to be differentially expressed in trypanosome-stimulated vs. non-stimulated flies. Functional annotation revealed that several of these proteins have important functions that could be involved in modulating the fly infection process by trypanosomes (and thus fly vector competence), including anti-oxidant and anti-apoptotic, cellular detoxifying, trypanosome agglutination, and immune stimulating or depressive effects. The results show a strong potential for diminishing or even disrupting fly vector competence, and their application holds great promise for improving the control of sleeping sickness.
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Affiliation(s)
- Anne Geiger
- UMR 177, Institut de Recherche pour le Développement-CIRAD, CIRAD TA A-17/G Montpellier, France
| | | | - Bernadette Tchicaya
- UMR 177, Institut de Recherche pour le Développement-CIRAD, CIRAD TA A-17/G Montpellier, France
| | - Valérie Rofidal
- Plateforme de Spectrométrie de Masse Protéomique - MSPP, Biochimie et Physiologie Moléculaire des Plantes - UMR 5004 Centre National de la Recherche Scientifique/UMR 0386 INRA/Montpellier SupAgro/Université Montpellier II Montpellier, France
| | - Mathilde Decourcelle
- Plateforme de Spectrométrie de Masse Protéomique - MSPP, Biochimie et Physiologie Moléculaire des Plantes - UMR 5004 Centre National de la Recherche Scientifique/UMR 0386 INRA/Montpellier SupAgro/Université Montpellier II Montpellier, France
| | - Véronique Santoni
- Plateforme de Spectrométrie de Masse Protéomique - MSPP, Biochimie et Physiologie Moléculaire des Plantes - UMR 5004 Centre National de la Recherche Scientifique/UMR 0386 INRA/Montpellier SupAgro/Université Montpellier II Montpellier, France
| | - Sonia Hem
- Plateforme de Spectrométrie de Masse Protéomique - MSPP, Biochimie et Physiologie Moléculaire des Plantes - UMR 5004 Centre National de la Recherche Scientifique/UMR 0386 INRA/Montpellier SupAgro/Université Montpellier II Montpellier, France
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Genetic diversity and population structure of Trypanosoma brucei in Uganda: implications for the epidemiology of sleeping sickness and Nagana. PLoS Negl Trop Dis 2015; 9:e0003353. [PMID: 25695634 PMCID: PMC4335064 DOI: 10.1371/journal.pntd.0003353] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2014] [Accepted: 10/15/2014] [Indexed: 11/19/2022] Open
Abstract
Background While Human African Trypanosomiasis (HAT) is in decline on the continent of Africa, the disease still remains a major health problem in Uganda. There are recurrent sporadic outbreaks in the traditionally endemic areas in south-east Uganda, and continued spread to new unaffected areas in central Uganda. We evaluated the evolutionary dynamics underpinning the origin of new foci and the impact of host species on parasite genetic diversity in Uganda. We genotyped 269 Trypanosoma brucei isolates collected from different regions in Uganda and southwestern Kenya at 17 microsatellite loci, and checked for the presence of the SRA gene that confers human infectivity to T. b. rhodesiense. Results Both Bayesian clustering methods and Discriminant Analysis of Principal Components partition Trypanosoma brucei isolates obtained from Uganda and southwestern Kenya into three distinct genetic clusters. Clusters 1 and 3 include isolates from central and southern Uganda, while cluster 2 contains mostly isolates from southwestern Kenya. These three clusters are not sorted by subspecies designation (T. b. brucei vs T. b. rhodesiense), host or date of collection. The analyses also show evidence of genetic admixture among the three genetic clusters and long-range dispersal, suggesting recent and possibly on-going gene flow between them. Conclusions Our results show that the expansion of the disease to the new foci in central Uganda occurred from the northward spread of T. b. rhodesiense (Tbr). They also confirm the emergence of the human infective strains (Tbr) from non-infective T. b. brucei (Tbb) strains of different genetic backgrounds, and the importance of cattle as Tbr reservoir, as confounders that shape the epidemiology of sleeping sickness in the region. Human African Trypanosomiasis (HAT) is a major health problem in Uganda, as there are recurrent sporadic outbreaks of the disease in traditionally endemic areas in south-east Uganda, and continued spread to new unaffected areas in central Uganda. In this study, we evaluate the evolutionary dynamics underpinning the origin of new disease foci and the impact of host species on parasite genetic diversity in Uganda. We found three distinct genetic clusters of T. brucei in Uganda and southwestern Kenya. Clusters 1 and 3 include isolates from central and southern Uganda, while cluster 2 contains mostly isolates from southwestern Kenya. These three clusters are not sorted by subspecies designation (T. b. brucei vs T. b. rhodesiense), host or date of collection. Our results show expansion of the disease to new foci in central Uganda occurred from the northward spread of T. b. rhodesiense. They also confirm the emergence of the human infective strains from non-infective T. b. brucei strains of different genetic backgrounds, and the importance of cattle as Tbr reservoir, as confounders that shape the epidemiology of sleeping sickness in the region.
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Geiger A, Ponton F, Simo G. Adult blood-feeding tsetse flies, trypanosomes, microbiota and the fluctuating environment in sub-Saharan Africa. ISME JOURNAL 2014; 9:1496-507. [PMID: 25500509 DOI: 10.1038/ismej.2014.236] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2014] [Revised: 11/03/2014] [Accepted: 11/06/2014] [Indexed: 01/01/2023]
Abstract
The tsetse fly vector transmits the protozoan Trypanosoma brucei, responsible for Human African Trypanosomiasis, one of the most neglected tropical diseases. Despite a recent decline in new cases, it is still crucial to develop alternative strategies to combat this disease. Here, we review the literature on the factors that influence trypanosome transmission from the fly vector to its vertebrate host (particularly humans). These factors include climate change effects to pathogen and vector development (in particular climate warming), as well as the distribution of host reservoirs. Finally, we present reports on the relationships between insect vector nutrition, immune function, microbiota and infection, to demonstrate how continuing research on the evolving ecology of these complex systems will help improve control strategies. In the future, such studies will be of increasing importance to understand how vector-borne diseases are spread in a changing world.
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Affiliation(s)
- Anne Geiger
- UMR 177, IRD-CIRAD, CIRAD TA A-17/G, Campus International de Baillarguet, Montpellier Cedex 5, France
| | - Fleur Ponton
- 1] School of Biological Sciences, The University of Sydney, Sydney, New South Wales, Australia [2] The Charles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia
| | - Gustave Simo
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
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Dias FDA, Vasconcellos LRDC, Romeiro A, Attias M, Souto-Padrón TC, Lopes AH. Transovum transmission of trypanosomatid cysts in the Milkweed bug, Oncopeltus fasciatus. PLoS One 2014; 9:e108746. [PMID: 25259791 PMCID: PMC4178184 DOI: 10.1371/journal.pone.0108746] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2014] [Accepted: 08/25/2014] [Indexed: 11/19/2022] Open
Abstract
Leptomonas wallacei is a trypanosomatid that develops promastigotes and cystic forms in the gut of the hemipteran insect Oncopeltus fasciatus. Insect trypanosomatids are thought to be solely transmitted from one host to another through the ingestion of parasite-contaminated feces. However, here we show that L. wallacei cysts present on the eggshells of eggs laid by O. fasciatus can also act as infective forms that are transmitted to the insect offspring. Newly hatched O. faciatus nymphs are parasite-free, but some of them become contaminated with L. wallacei after feeding on eggshell remnants. The present study is the first report of transovum transmission of a trypanosomatid, a process that may have a relevant role in parasite’s within-host population dynamics.
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Affiliation(s)
- Felipe de Almeida Dias
- Instituto de Bioquímica Médica Leopoldo de Meis, Programa de Biologia Molecular e Biotecnologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | | | - Alexandre Romeiro
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Marcia Attias
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Thais Cristina Souto-Padrón
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Angela Hampshire Lopes
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
- * E-mail:
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Limou S, Nelson GW, Kopp JB, Winkler CA. APOL1 kidney risk alleles: population genetics and disease associations. Adv Chronic Kidney Dis 2014; 21:426-33. [PMID: 25168832 DOI: 10.1053/j.ackd.2014.06.005] [Citation(s) in RCA: 135] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 06/09/2014] [Accepted: 06/09/2014] [Indexed: 01/13/2023]
Abstract
APOL1 kidney disease is a unique case in the field of the genetics of common disease: 2 variants (termed G1 and G2) with high population frequency have been repeatedly associated with nondiabetic CKDs, with very strong effect size (odds ratios 3-29) in populations of sub-Saharan African descent. This review provides an update on the spectrum of APOL1 kidney disease and on the worldwide distribution of these kidney risk variants. We also summarize the proper way to run a recessive analysis on joint and independent effects of APOL1 G1 and G2 kidney risk variants.
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Serological responses and biomarker evaluation in mice and pigs exposed to tsetse fly bites. PLoS Negl Trop Dis 2014; 8:e2911. [PMID: 24853371 PMCID: PMC4031185 DOI: 10.1371/journal.pntd.0002911] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Accepted: 04/16/2014] [Indexed: 12/02/2022] Open
Abstract
Background Tsetse flies are obligate blood-feeding insects that transmit African trypanosomes responsible for human sleeping sickness and nagana in livestock. The tsetse salivary proteome contains a highly immunogenic family of the endonuclease-like Tsal proteins. In this study, a recombinant version of Tsal1 (rTsal1) was evaluated in an indirect ELISA to quantify the contact with total Glossina morsitans morsitans saliva, and thus the tsetse fly bite exposure. Methodology/Principal Findings Mice and pigs were experimentally exposed to different G. m. morsitans exposure regimens, followed by a long-term follow-up of the specific antibody responses against total tsetse fly saliva and rTsal1. In mice, a single tsetse fly bite was sufficient to induce detectable IgG antibody responses with an estimated half-life of 36–40 days. Specific antibody responses could be detected for more than a year after initial exposure, and a single bite was sufficient to boost anti-saliva immunity. Also, plasmas collected from tsetse-exposed pigs displayed increased anti-rTsal1 and anti-saliva IgG levels that correlated with the exposure intensity. A strong correlation between the detection of anti-rTsal1 and anti-saliva responses was recorded. The ELISA test performance and intra-laboratory repeatability was adequate in the two tested animal models. Cross-reactivity of the mouse IgGs induced by exposure to different Glossina species (G. m. morsitans, G. pallidipes, G. palpalis gambiensis and G. fuscipes) and other hematophagous insects (Stomoxys calcitrans and Tabanus yao) was evaluated. Conclusion This study illustrates the potential use of rTsal1 from G. m. morsitans as a sensitive biomarker of exposure to a broad range of Glossina species. We propose that the detection of anti-rTsal1 IgGs could be a promising serological indicator of tsetse fly presence that will be a valuable tool to monitor the impact of tsetse control efforts on the African continent. Salivary proteins of hematophagous disease vectors represent potential biomarkers of exposure and could be used in serological assays that are complementary to entomological surveys. We illustrate that a recombinant version of the highly immunogenic Tsal1 protein of the savannah tsetse fly (Glossina morsitans morsitans) is a sensitive immunological probe to detect contact with tsetse flies. Experimental exposure of mice and pigs to different regimens of tsetse fly bites combined with serological testing revealed that rTsal1 is a sensitive indicator that can differentiate the various degrees of exposure of animals. Tsetse-induced antibodies persisted relatively long, and an efficient boosting of immunity was observed upon re-exposure. Recombinant Tsal1 is a promising candidate to detect contact with various tsetse species, which would enable screening of populations or herds for exposure to tsetse flies in various areas on the African continent. This exposure indicator could be a valuable tool to monitor the impact of vector control programs and to detect re-invasion of cleared areas by tsetse flies.
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Analysis of multiple tsetse fly populations in Uganda reveals limited diversity and species-specific gut microbiota. Appl Environ Microbiol 2014; 80:4301-12. [PMID: 24814785 DOI: 10.1128/aem.00079-14] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The invertebrate microbiome contributes to multiple aspects of host physiology, including nutrient supplementation and immune maturation processes. We identified and compared gut microbial abundance and diversity in natural tsetse flies from Uganda using five genetically distinct populations of Glossina fuscipes fuscipes and multiple tsetse species (Glossina morsitans morsitans, G. f. fuscipes, and Glossina pallidipes) that occur in sympatry in one location. We used multiple approaches, including deep sequencing of the V4 hypervariable region of the 16S rRNA gene, 16S rRNA gene clone libraries, and bacterium-specific quantitative PCR (qPCR), to investigate the levels and patterns of gut microbial diversity from a total of 151 individuals. Our results show extremely limited diversity in field flies of different tsetse species. The obligate endosymbiont Wigglesworthia dominated all samples (>99%), but we also observed wide prevalence of low-density Sodalis (tsetse's commensal endosymbiont) infections (<0.05%). There were also several individuals (22%) with high Sodalis density, which also carried coinfections with Serratia. Albeit in low density, we noted differences in microbiota composition among the genetically distinct G. f. fuscipes flies and between different sympatric species. Interestingly, Wigglesworthia density varied in different species (10(4) to 10(6) normalized genomes), with G. f. fuscipes having the highest levels. We describe the factors that may be responsible for the reduced diversity of tsetse's gut microbiota compared to those of other insects. Additionally, we discuss the implications of Wigglesworthia and Sodalis density variations as they relate to trypanosome transmission dynamics and vector competence variations associated with different tsetse species.
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Sternberg ED, Thomas MB. Local adaptation to temperature and the implications for vector-borne diseases. Trends Parasitol 2014; 30:115-22. [DOI: 10.1016/j.pt.2013.12.010] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Revised: 12/24/2013] [Accepted: 12/28/2013] [Indexed: 12/29/2022]
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Wardrop NA, Fèvre EM, Atkinson PM, Welburn SC. The dispersal ecology of Rhodesian sleeping sickness following its introduction to a new area. PLoS Negl Trop Dis 2013; 7:e2485. [PMID: 24130913 PMCID: PMC3794918 DOI: 10.1371/journal.pntd.0002485] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Accepted: 09/06/2013] [Indexed: 11/24/2022] Open
Abstract
Tsetse-transmitted human and animal trypanosomiasis are constraints to both human and animal health in sub-Saharan Africa, and although these diseases have been known for over a century, there is little recent evidence demonstrating how the parasites circulate in natural hosts and ecosystems. The spread of Rhodesian sleeping sickness (caused by Trypanosoma brucei rhodesiense) within Uganda over the past 15 years has been linked to the movement of infected, untreated livestock (the predominant reservoir) from endemic areas. However, despite an understanding of the environmental dependencies of sleeping sickness, little research has focused on the environmental factors controlling transmission establishment or the spatially heterogeneous dispersal of disease following a new introduction. In the current study, an annually stratified case-control study of Rhodesian sleeping sickness cases from Serere District, Uganda was used to allow the temporal assessment of correlations between the spatial distribution of sleeping sickness and landscape factors. Significant relationships were detected between Rhodesian sleeping sickness and selected factors, including elevation and the proportion of land which was "seasonally flooding grassland" or "woodlands and dense savannah." Temporal trends in these relationships were detected, illustrating the dispersal of Rhodesian sleeping sickness into more 'suitable' areas over time, with diminishing dependence on the point of introduction in concurrence with an increasing dependence on environmental and landscape factors. These results provide a novel insight into the ecology of Rhodesian sleeping sickness dispersal and may contribute towards the implementation of evidence-based control measures to prevent its further spread.
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Affiliation(s)
- Nicola A. Wardrop
- Geography and Environment, University of Southampton, Highfield Campus, Southampton, United Kingdom
| | - Eric M. Fèvre
- Institute of Infection and Global Health, University of Liverpool, Leahurst Campus, Neston, United Kingdom
| | - Peter M. Atkinson
- Geography and Environment, University of Southampton, Highfield Campus, Southampton, United Kingdom
| | - Susan C. Welburn
- School of Biomedical Sciences, University of Edinburgh, Chancellors Building, Edinburgh, United Kingdom
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Genetically distinct Glossina fuscipes fuscipes populations in the Lake Kyoga region of Uganda and its relevance for human African trypanosomiasis. BIOMED RESEARCH INTERNATIONAL 2013; 2013:614721. [PMID: 24199195 PMCID: PMC3807537 DOI: 10.1155/2013/614721] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 08/19/2013] [Indexed: 11/18/2022]
Abstract
Tsetse flies (Glossina spp.) are the sole vectors of Trypanosoma brucei—the agent of human (HAT) and animal (AAT) trypanosomiasis. Glossina fuscipes fuscipes (Gff) is the main vector species in Uganda—the only country where the two forms of HAT disease (rhodesiense and gambiense) occur, with gambiense limited to the northwest. Gff populations cluster in three genetically distinct groups in northern, southern, and western Uganda, respectively, with a contact zone present in central Uganda. Understanding the dynamics of this contact zone is epidemiologically important as the merger of the two diseases is a major health concern. We used mitochondrial and microsatellite DNA data from Gff samples in the contact zone to understand its spatial extent and temporal stability. We show that this zone is relatively narrow, extending through central Uganda along major rivers with south to north introgression but displaying no sex-biased dispersal. Lack of obvious vicariant barriers suggests that either environmental conditions or reciprocal competitive exclusion could explain the patterns of genetic differentiation observed. Lack of admixture between northern and southern populations may prevent the sympatry of the two forms of HAT disease, although continued control efforts are needed to prevent the recolonization of tsetse-free regions by neighboring populations.
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