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Lilak AA, Pecor DB, Matulis G, Potter AM, Wofford RN, Kearney MF, Mitchell S, Jaradat F, Kano A, Zimmerman DM, Hassell JM, Kumsa B, Kamau M, Linton YM, von Fricken ME. Data release: targeted systematic literature search for tick and tick-borne pathogen distributions in six countries in sub-Saharan Africa from 1901 to 2020. Parasit Vectors 2024; 17:84. [PMID: 38389097 PMCID: PMC10885379 DOI: 10.1186/s13071-023-06086-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 12/07/2023] [Indexed: 02/24/2024] Open
Abstract
BACKGROUND Surveillance data documenting tick and tick-borne disease (TBD) prevalence is needed to develop risk assessments and implement control strategies. Despite extensive research in Africa, there is no standardized, comprehensive review. METHODS Here we tackle this knowledge gap, by producing a comprehensive review of research articles on ticks and TBD between 1901 and 2020 in Chad, Djibouti, Ethiopia, Kenya, Tanzania, and Uganda. Over 8356 English language articles were recovered. Our search strategy included 19 related MeSH terms. Articles were reviewed, and 331 met inclusion criteria. Articles containing mappable data were compiled into a standardized data schema, georeferenced, and uploaded to VectorMap. RESULTS Tick and pathogen matrixes were created, providing information on vector distributions and tick-pathogen associations within the six selected African countries. CONCLUSIONS These results provide a digital, mappable database of current and historical tick and TBD distributions across six countries in Africa, which can inform specific risk modeling, determine surveillance gaps, and guide future surveillance priorities.
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Affiliation(s)
- Abigail A Lilak
- One Health Center of Excellence, Emerging Pathogens Institute, University of Florida, 2055 Mowry Road, Gainesville, FL, 32611, USA
- Department of Environmental & Global Health, University of Florida, Gainesville, FL, USA
| | - David B Pecor
- Walter Reed Biosystematics Unit (WRBU), Smithsonian Museum Support Center, Suitland, MD, USA
- Department of Entomology, Smithsonian Institution-National Museum of Natural History, Washington, DC, USA
- One Health Branch, Walter Reed Army Institute of Research (WRAIR), Silver Spring, Maryland, USA
| | - Graham Matulis
- One Health Center of Excellence, Emerging Pathogens Institute, University of Florida, 2055 Mowry Road, Gainesville, FL, 32611, USA
- Department of Environmental & Global Health, University of Florida, Gainesville, FL, USA
| | - Alexander M Potter
- Walter Reed Biosystematics Unit (WRBU), Smithsonian Museum Support Center, Suitland, MD, USA
- Department of Entomology, Smithsonian Institution-National Museum of Natural History, Washington, DC, USA
- One Health Branch, Walter Reed Army Institute of Research (WRAIR), Silver Spring, Maryland, USA
| | | | | | - Stephanie Mitchell
- Walter Reed Biosystematics Unit (WRBU), Smithsonian Museum Support Center, Suitland, MD, USA
| | | | - Arisa Kano
- George Mason University, Fairfax, VA, USA
| | - Dawn M Zimmerman
- Department of Entomology, Smithsonian Institution-National Museum of Natural History, Washington, DC, USA
- Yale University, New Haven, CT, USA
| | - James M Hassell
- Department of Entomology, Smithsonian Institution-National Museum of Natural History, Washington, DC, USA
- Yale University, New Haven, CT, USA
| | - Bersissa Kumsa
- Department of Pathology & Parasitology, College of Veterinary Medicine and Agriculture, Addis Ababa University, Bishoftu, Ethiopia
| | - Maureen Kamau
- Walter Reed Biosystematics Unit (WRBU), Smithsonian Museum Support Center, Suitland, MD, USA
- Mpala Research Center, Nanyuki, Kenya
| | - Yvonne-Marie Linton
- Walter Reed Biosystematics Unit (WRBU), Smithsonian Museum Support Center, Suitland, MD, USA
- Department of Entomology, Smithsonian Institution-National Museum of Natural History, Washington, DC, USA
- One Health Branch, Walter Reed Army Institute of Research (WRAIR), Silver Spring, Maryland, USA
| | - Michael E von Fricken
- One Health Center of Excellence, Emerging Pathogens Institute, University of Florida, 2055 Mowry Road, Gainesville, FL, 32611, USA.
- Department of Environmental & Global Health, University of Florida, Gainesville, FL, USA.
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Tick Diversity and Distribution of Hard (Ixodidae) Cattle Ticks in South Africa. MICROBIOLOGY RESEARCH 2023. [DOI: 10.3390/microbiolres14010004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Ticks are amongst the important ectoparasites where livestock are concerned, as they adversely affect the animals through bloodsucking. In tropical and subtropical countries, they transmit pathogens such as babesiosis, theileriosis, ehrlichiosis, and anaplasmosis in cattle, causing a reduction in production rate and significant concomitant economic losses. Ticks affect 80% of the cattle population across the world, with an estimated economic loss of USD 20–30 billion per year. In South Africa, economic losses in the livestock industry caused by ticks and tick-borne diseases are estimated to exceed USD 33 million per year (ZAR 500 million). There are seven major genera of ixodid ticks in Southern Africa (i.e., Amblyomma, Dermacentor, Haemaphysalis, Hyalomma, Ixodes and Rhipicephalus). The environment in which a tick lives is made up of all the various biological and abiotic factors that are either necessary or unnecessary for its life. The areas where various ticks have been found have been documented in many publications. Using these data, maps of possible species’ habitats can be made. Historical records on tick distribution may be incorrect due to identification mistakes or a change in the tick’s name. All the sources used to generate the maps for this review were unpublished and came from a wide range of sources. To identify tick species and the accompanying microbial ecosystems, researchers are increasingly adopting tick identification methods including 16S and 18S rDNA gene sequencing. Indeed, little is known about the genetic alterations that give important traits, including the predilection for tick hosts, transmission, and acaricide resistance. Opportunities for exploring these changes in tick populations and subpopulations are provided by advancements in omics technologies. The literature on the variety of ixodid ticks, their direct and indirect effects, and control methods in South Africa is compiled in this review.
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Tawana M, Onyiche TE, Ramatla T, Mtshali S, Thekisoe O. Epidemiology of Ticks and Tick-Borne Pathogens in Domestic Ruminants across Southern African Development Community (SADC) Region from 1980 until 2021: A Systematic Review and Meta-Analysis. Pathogens 2022; 11:pathogens11080929. [PMID: 36015049 PMCID: PMC9414594 DOI: 10.3390/pathogens11080929] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 04/14/2022] [Accepted: 04/15/2022] [Indexed: 11/16/2022] Open
Abstract
Ticks are hematophagous ectoparasites that are capable of infesting a wide range of mammals, including domestic animals, ruminants, wildlife, and humans across the world, and they transmit disease-causing pathogens. Numerous individual epidemiological studies have been conducted on the distribution and prevalence of ticks and tick-borne diseases (TBDs) in the Southern African Developing Community (SADC) region, but no effort has been undertaken to synchronize findings, which would be helpful in the implementation of consolidated tick control measures. With the aim of generating consolidated pooled prevalence estimates of ticks and TBDs in the SADC region, we performed a systematic review and meta-analysis of published articles using the PRISMA 2020 guidelines. A deep search was performed on five electronic databases, namely, PubMed, ScienceDirect, Google Scholar, AJOL, and Springer Link. Of the 347 articles identified, only 61 of the articles were eligible for inclusion. In total, 18,355 tick specimens were collected, belonging to the genera Amblyomma, Haemaphysalis, Hyalomma, and Rhipicephalus (including Boophilus) across several countries, including South Africa (n = 8), Tanzania (n = 3), Zambia (n = 2), Zimbabwe (n = 2), Madagascar (n = 2), Angola (n = 2), Mozambique (n = 1), and Comoros (n = 1). The overall pooled prevalence estimate (PPE) of TBPs in livestock was 52.2%, with the highest PPE in cattle [51.2%], followed by sheep [45.4%], and goats [29.9%]. For bacteria-like and rickettsial TBPs, Anaplasma marginale had the highest PPE of 45.9%, followed by A. centrale [14.7%], A. phagocytophilum [2.52%], and A. bovis [0.88%], whilst Ehrlichia ruminantium had a PPE of 4.2%. For piroplasmids, Babesia bigemina and B. bovis had PPEs of 20.8% and 20.3%, respectively. Theileria velifera had the highest PPE of 43.0%, followed by T. mutans [29.1%], T. parva [25.0%], and other Theileria spp. [14.06%]. Findings from this study suggest the need for a consolidated scientific approach in the investigation of ticks, TBPs, and TBDs in the whole SADC region, as most of the TBDs are transboundary and require a regional control strategy.
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Affiliation(s)
- Mpho Tawana
- Unit for Environmental Sciences and Management, North-West University, Potchefstroom 2531, South Africa
| | - ThankGod E. Onyiche
- Department of Veterinary Parasitology and Entomology, University of Maiduguri, Maiduguri 600230, Nigeria
| | - Tsepo Ramatla
- Unit for Environmental Sciences and Management, North-West University, Potchefstroom 2531, South Africa
- Correspondence: ; Tel.: +27-18-299-2521
| | - Sibusiso Mtshali
- Foundational Research and Services, South African National Biodiversity Institute, National Zoological Gardens, Pretoria 0001, South Africa
- University of Limpopo, Private Bag X1106, Sovenga 0727, South Africa
| | - Oriel Thekisoe
- Unit for Environmental Sciences and Management, North-West University, Potchefstroom 2531, South Africa
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Pérez-Sánchez R, Cano-Argüelles AL, González-Sánchez M, Oleaga A. First Data on Ornithodoros moubata Aquaporins: Structural, Phylogenetic and Immunogenic Characterisation as Vaccine Targets. Pathogens 2022; 11:pathogens11060694. [PMID: 35745548 PMCID: PMC9227307 DOI: 10.3390/pathogens11060694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 06/14/2022] [Accepted: 06/15/2022] [Indexed: 11/30/2022] Open
Abstract
Ornithodoros moubata transmits African swine fever and human relapsing fever in Africa. The elimination of O. moubata populations from anthropic environments is expected to improve the prevention and control of these diseases. Tick vaccines have emerged as a sustainable method for tick control, and tick aquaporins (AQPs) are promising targets for tick vaccines due to their vital functions, immunogenicity and ease of access by neutralising host antibodies. This study aimed at the systematic identification of the AQPs expressed by O. moubata (OmAQPs) and their characterisation as vaccine targets. Therefore, AQP coding sequences were recovered from available transcriptomic datasets, followed by PCR amplification, cloning, sequence verification and the analysis of the AQP protein structure and epitope exposure. Seven OmAQPs were identified and characterised: six were aquaglyceroporins, and one was a water-specific aquaporin. All of these were expressed in the salivary glands and midgut and only three in the coxal glands. Epitope exposure analysis identified three extracellular domains in each AQP, which concentrate overlapping B and T cell epitopes, making them interesting vaccine targets. Based on these domain sequences, a set of ten antigenic peptides was designed, which showed adequate properties to be produced and tested in pilot vaccine trials.
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Maqbool M, Sajid MS, Saqib M, Anjum FR, Tayyab MH, Rizwan HM, Rashid MI, Rashid I, Iqbal A, Siddique RM, Shamim A, Hassan MA, Atif FA, Razzaq A, Zeeshan M, Hussain K, Nisar RHA, Tanveer A, Younas S, Kamran K, Rahman SU. Potential Mechanisms of Transmission of Tick-Borne Viruses at the Virus-Tick Interface. Front Microbiol 2022; 13:846884. [PMID: 35602013 PMCID: PMC9121816 DOI: 10.3389/fmicb.2022.846884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Accepted: 03/18/2022] [Indexed: 11/13/2022] Open
Abstract
Ticks (Acari; Ixodidae) are the second most important vector for transmission of pathogens to humans, livestock, and wildlife. Ticks as vectors for viruses have been reported many times over the last 100 years. Tick-borne viruses (TBVs) belong to two orders (Bunyavirales and Mononegavirales) containing nine families (Bunyaviridae, Rhabdoviridae, Asfarviridae, Orthomyxovirida, Reoviridae, Flaviviridae, Phenuviridae, Nyamiviridae, and Nairoviridae). Among these TBVs, some are very pathogenic, causing huge mortality, and hence, deserve to be covered under the umbrella of one health. About 38 viral species are being transmitted by <10% of the tick species of the families Ixodidae and Argasidae. All TBVs are RNA viruses except for the African swine fever virus from the family Asfarviridae. Tick-borne viral diseases have also been classified as an emerging threat to public health and animals, especially in resource-poor communities of the developing world. Tick-host interaction plays an important role in the successful transmission of pathogens. The ticks' salivary glands are the main cellular machinery involved in the uptake, settlement, and multiplication of viruses, which are required for successful transmission into the final host. Furthermore, tick saliva also participates as an augmenting tool during the physiological process of transmission. Tick saliva is an important key element in the successful transmission of pathogens and contains different antimicrobial proteins, e.g., defensin, serine, proteases, and cement protein, which are key players in tick-virus interaction. While tick-virus interaction is a crucial factor in the propagation of tick-borne viral diseases, other factors (physiological, immunological, and gut flora) are also involved. Some immunological factors, e.g., toll-like receptors, scavenger receptors, Janus-kinase (JAK-STAT) pathway, and immunodeficiency (IMD) pathway are involved in tick-virus interaction by helping in virus assembly and acting to increase transmission. Ticks also harbor some endogenous viruses as internal microbial faunas, which also play a significant role in tick-virus interaction. Studies focusing on tick saliva and its role in pathogen transmission, tick feeding, and control of ticks using functional genomics all point toward solutions to this emerging threat. Information regarding tick-virus interaction is somewhat lacking; however, this information is necessary for a complete understanding of transmission TBVs and their persistence in nature. This review encompasses insight into the ecology and vectorial capacity of tick vectors, as well as our current understanding of the predisposing, enabling, precipitating, and reinforcing factors that influence TBV epidemics. The review explores the cellular, biochemical, and immunological tools which ensure and augment successful evading of the ticks' defense systems and transmission of the viruses to the final hosts at the virus-vector interface. The role of functional genomics, proteomics, and metabolomics in profiling tick-virus interaction is also discussed. This review is an initial attempt to comprehensively elaborate on the epidemiological determinants of TBVs with a focus on intra-vector physiological processes involved in the successful execution of the docking, uptake, settlement, replication, and transmission processes of arboviruses. This adds valuable data to the existing bank of knowledge for global stakeholders, policymakers, and the scientific community working to devise appropriate strategies to control ticks and TBVs.
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Affiliation(s)
- Mahvish Maqbool
- Department of Parasitology, University of Agriculture, Faisalabad, Pakistan
| | - Muhammad Sohail Sajid
- Department of Parasitology, University of Agriculture, Faisalabad, Pakistan
- Department of Epidemiology and Public Health, University of Agriculture, Faisalabad, Pakistan
| | - Muhammad Saqib
- Department of Clinical Medicine and Surgery, University of Agriculture, Faisalabad, Pakistan
| | - Faisal Rasheed Anjum
- Department of Epidemiology and Public Health, University of Agriculture, Faisalabad, Pakistan
- Institute of Microbiology, University of Agriculture, Faisalabad, Pakistan
| | - Muhammad Haleem Tayyab
- Department of Clinical Medicine and Surgery, University of Agriculture, Faisalabad, Pakistan
| | - Hafiz Muhammad Rizwan
- Section of Parasitology, Department of Pathobiology, KBCMA College of Veterinary and Animal Sciences Narowal, Lahore, Pakistan
| | - Muhammad Imran Rashid
- Department of Parasitology, University of Veterinary and Animal Sciences, Lahore, Pakistan
| | - Imaad Rashid
- Department of Clinical Medicine and Surgery, University of Agriculture, Faisalabad, Pakistan
| | - Asif Iqbal
- Section of Parasitology, Department of Pathobiology, Riphah College of Veterinary Sciences, Riphah International University, Lahore, Pakistan
| | - Rao Muhammad Siddique
- Section of Parasitology, Department of Pathobiology, Riphah College of Veterinary Sciences, Riphah International University, Lahore, Pakistan
| | - Asim Shamim
- Department of Pathobiology, University of the Poonch Rawalakot, Rawalakot, Pakistan
| | - Muhammad Adeel Hassan
- Department of Parasitology, Cholistan University of Veterinary and Animal Sciences, Bahawalpur, Pakistan
| | - Farhan Ahmad Atif
- Medicine Section, Department of Clinical Sciences, Collège of Veterinary and Animal Sciences, Jhang, Pakistan
- University of Veterinary and Animal Sciences, Lahore, Pakistan
| | - Abdul Razzaq
- Agricultural Linkages Program, Pakistan Agriculture Research Council, Islamabad, Pakistan
| | - Muhammad Zeeshan
- Department of Parasitology, University of Agriculture, Faisalabad, Pakistan
| | - Kashif Hussain
- Department of Parasitology, University of Agriculture, Faisalabad, Pakistan
| | | | - Akasha Tanveer
- Department of Parasitology, University of Agriculture, Faisalabad, Pakistan
| | - Sahar Younas
- Department of Parasitology, University of Agriculture, Faisalabad, Pakistan
| | - Kashif Kamran
- Department of Zoology, University of Balochistan, Quetta, Pakistan
| | - Sajjad ur Rahman
- Institute of Microbiology, University of Agriculture, Faisalabad, Pakistan
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Chitimia-Dobler L, Mans BJ, Handschuh S, Dunlop JA. A remarkable assemblage of ticks from mid-Cretaceous Burmese amber. Parasitology 2022; 149:1-36. [PMID: 35241194 PMCID: PMC10090602 DOI: 10.1017/s0031182022000269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 02/25/2022] [Accepted: 02/25/2022] [Indexed: 11/06/2022]
Abstract
Four fossil ticks (Arachnida: Parasitiformes: Ixodida) are described from mid-Cretaceous (ca. 100 Ma) Burmese amber of Myanmar. Ixodes antiquorum sp. nov. (Ixodidae) is the first Mesozoic record of Ixodes and the oldest representative of the most species-rich extant tick genus. Its affinities appear to lie with modern Australian forms, consistent with the hypothesis that Burmese amber hosted Gondwanan faunal elements. Even more remarkable is Khimaira fossus gen. et sp. nov. which combines a body resembling that of a soft tick (Argasidae) with a basis capitulum more like that of a hard tick (Ixodidae). We refer it to Khimairidae fam. nov. as a possible transitional form between the two main families of ticks alive today. Another member of the extinct Deinocrotonidae is described as Deinocroton copia sp. nov., while the first described adult female for Cornupalpatum burmanicum is associated with a dinosaur feather barb.
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Affiliation(s)
| | - Ben J. Mans
- Epidemiology, Parasites and Vectors, Agricultural Research Council-Onderstepoort Veterinary Research, Onderstepoort, South Africa
- The Department of Veterinary Tropical Diseases, University of Pretoria, Pretoria, South Africa
- Department of Life and Consumer Sciences, University of South Africa, Pretoria, South Africa
| | - Stephan Handschuh
- VetCore Facility for Research, Veterinärmedizinische Universität Wien, Veterinärplatz 1, A-1210Vienna, Austria
| | - Jason A. Dunlop
- Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstrasse 43, D-10115Berlin, Germany
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Nuclear (18S-28S rRNA) and mitochondrial genome markers of Carios (Carios) vespertilionis (Argasidae) support Carios Latreille, 1796 as a lineage embedded in the Ornithodorinae: re-classification of the Carios sensu Klompen and Oliver (1993) clade into its respective subgenera. Ticks Tick Borne Dis 2021; 12:101688. [PMID: 33652332 DOI: 10.1016/j.ttbdis.2021.101688] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 02/08/2021] [Accepted: 02/10/2021] [Indexed: 11/20/2022]
Abstract
Argasid systematics remains controversial with widespread adherence to the Hoogstraal (1985) classification scheme, even though it does not reflect evolutionary relationships and results in paraphyly for the main genera of soft ticks (Argasidae), namely Argas and Ornithodoros. The alternative classification scheme, proposed by Klompen and Oliver (1993), has problems of its own: most notably paraphyly of the subgenus Pavlovskyella and the controversial grouping together of the subgenera Alectorobius, Antricola, Carios, Chiropterargas, Nothoaspis, Parantricola, Reticulinasus and Subparmatus into the genus Carios. Recent phylogenetic analyses of 18S/28S rRNA sequences and mitochondrial genomes agree with the scheme of Klompen and Oliver (1993), with regard to the paraphyly of Pavlovskyella, placement of Alveonasus, Ogadenus, Proknekalia and Secretargas in the Argasinae and placement of Carios and Chiropterargas in the Ornithodorinae (Mans et al., 2019). The Carios clade and its constituent subgenera remain controversial, since the phylogenetic position of its type species Carios (Carios) vespertilionis Latreille, 1796 (formerly Argas vespertilionis) has not been determined with confidence. The current study aimed to resolve Carios sensu lato Klompen and Oliver, 1993, and Carios sensu stricto Hoogstraal, 1985, by determining and analysing phylogenetic nuclear and mitochondrial markers for C. (C.) vespertilionis. Both the nuclear and mitochondrial markers support placement of Carios s.s. within the subfamily Ornithodorinae, but to the exclusion of the clade that includes the 6 other subgenera that are part of Carios s.l. Klompen and Oliver (1993), namely Alectorobius, Antricola, Nothoaspis, Parantricola, Reticulinasus and Subparmatus. These 6 subgenera form a monophyletic clade that might be placed as new subgenera within the genus Alectorobius, or elevated to genera. Given the substantial differences in biology among these subgenera, we propose that these 6 subgenera be elevated to genera. Thus, we propose to modify the classification scheme of Mans et al. (2019) so that the subfamily Argasinae now has six genera, Alveonasus, Argas (subgenera Argas and Persicargas), Navis, Ogadenus, Proknekalia and Secretargas, and the subfamily Ornithodorinae has nine genera, Alectorobius, Antricola (subgenera Antricola and Parantricola), Carios, Chiropterargas, Nothoaspis, Ornithodoros (subgenera Microargas, Ornamentum, Ornithodoros, Pavlovskyella and Theriodoros), Otobius, Reticulinasus and Subparmatus (genera indicated in bold).
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Toaleb NI, Gabr HSM, Abd El-Shafy S, Abdel-Rahman EH. Evaluation of vaccine candidates purified from the adult ticks of Ornithodoros savignyi (Acari: Argasidae) and Hyalomma dromedarii (Acari: Ixodidae) against tick infestations. J Parasit Dis 2019; 43:246-255. [PMID: 31263330 PMCID: PMC6570741 DOI: 10.1007/s12639-018-01082-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 12/31/2018] [Indexed: 12/15/2022] Open
Abstract
Ticks cause anemia, toxicosis, growth delay, and transmit infectious diseases in animals and humans. The current study aimed to evaluate the immunoprophylactic properties of two vaccine candidates to develop vaccine against tick infestations. These two vaccine candidates were specific fraction from the adults of the soft tick Ornithodoros savignyi and cross-reactive fraction from the adults of the hard tick Hyalomma dromedarii. Both specific and cross-reactive fractions were isolated by Cyanogen Bromide-activated Sepharose-4B affinity column chromatography. Both candidates proved their cross-reactivity by enzyme linked immunosorbent assay and Western blot. Characterization of the two vaccines by SDS-PAGE showed that the O. savignyi specific fraction consists of four bands; 97, 85, 66 and 11.5 kDa compared with nine bands associated with its crude antigen (196-11.5 kDa). The H. dromedarii cross-reactive vaccine candidate consists of three bands; 97, 66 and 45 kDa compared to eight bands of its crude antigen (196-21 kDa). Two common bands of 97 and 66 kDa between two candidates showed immunogenic cross-reactivity with the developed antisera of both infestations by Western blot. Immunization of rabbits intramuscularly with two doses of the fractions separately (40 µg/kg) led to immunological and parasitological changes. Immunologically; the level of immunoglobulins in vaccinated rabbits increased significantly compared with control infested non-vaccinated rabbits. These immunoglobulins are probably responsible for the protective effect of both candidates. Parasitologically, immunized rabbits showed protection against infestation by adult ticks as proved by significant feeding rejection percentage and significant reduction in egg and engorgement weights of H. dromedarii. While insignificant protection was observed against O. savignyi ticks infestation in feeding rejection and reduction in engorgement weight. In conclusion, this study suggests promising immunoprophylactic potentials of the purified fractions against tick infestations in rabbits through induction of IgG responses. The protective effect of both vaccine candidates deserves further evaluation in other hosts and against other tick infestations.
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Affiliation(s)
- Nagwa I. Toaleb
- Department of Parasitology and Animal Diseases, Veterinary Research Division, National Research Centre, Dokki, Giza, Egypt
| | - Hanan S. M. Gabr
- Department of Zoology and Agricultural Nematology, Faculty of Agriculture, Cairo University, Giza, Egypt
| | - Sobhy Abd El-Shafy
- Department of Parasitology and Animal Diseases, Veterinary Research Division, National Research Centre, Dokki, Giza, Egypt
| | - Eman H. Abdel-Rahman
- Department of Parasitology and Animal Diseases, Veterinary Research Division, National Research Centre, Dokki, Giza, Egypt
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Abstract
Improved understanding of tick phylogeny has allowed testing of some biogeographical patterns. On the basis of both literature data and a meta-analysis of available sequence data, there is strong support for a Gondwanan origin of Ixodidae, and probably Ixodida. A particularly strong pattern is observed for the genus Amblyomma, which appears to have originated in Antarctica/southern South America, with subsequent dispersal to Australia. The endemic Australian lineages of Ixodidae (no other continent has such a pattern) appear to result from separate dispersal events, probably from Antarctica. Minimum ages for a number of divergences are determined as part of an updated temporal framework for tick evolution. Alternative hypotheses for tick evolution, such as a very old Pangean group, a Northern hemisphere origin, or an Australian origin, fit less well with observed phylogeographic patterns.
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Affiliation(s)
- Lorenza Beati
- Institute for Coastal Plain Science and US National Tick Collection, Georgia Southern University, Statesboro, Georgia 30460, USA;
| | - Hans Klompen
- Department of Evolution, Ecology, and Organismal Biology and Museum of Biological Diversity, The Ohio State University, Columbus, Ohio 43212, USA
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Abstract
AbstractThe first fossil potentially assignable to the extant hard tick genus Haemaphysalis CL Koch (1844) (Ixodida: Ixodidae) is described from the Late Cretaceous (ca. 99 Ma) Burmese amber of Myanmar. Haemaphysalis (Alloceraea) cretacea sp. nov. is the oldest and only fossil representative of this genus; living members of which predominantly feed on mammals. Their typical hosts are known since at least the Jurassic and the discovery of a mid-Cretaceous parasite, which might have fed on mammals raises again the question of to what extent ticks are coupled to their (modern) host groups. An inferred Triassic split of Argasidae (soft ticks) into the bird-preferring Argasinae and mammal-preferring Ornithodorinae dates to about the time when dinosaurs (later including birds) and mammaliaforms as potential hosts were emerging. Ixodidae may have split into Prostriata and Metastriata shortly after the end-Permian mass extinction, an event which fundamentally altered the terrestrial vertebrate fauna. Prostriata (the genus Ixodes) prefer birds and mammals today, and some may have used groups like cynodonts in the Triassic. Basal metastriate ticks (e.g. Amblyomma) prefer reptiles, but derived metastriates (including Haemaphysalis) again prefer mammals. Here, we may be looking at a younger (Cretaceous?) shift associated with more recent mammalian radiations.
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In vitro bioassays used in evaluating plant extracts for tick repellent and acaricidal properties: A critical review. Vet Parasitol 2018; 254:160-171. [DOI: 10.1016/j.vetpar.2018.03.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 03/07/2018] [Accepted: 03/08/2018] [Indexed: 01/09/2023]
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Pienaar R, de Klerk DG, Putterill JF, Mans BJ. Notes on maternal behaviour in soft ticks: Specifically observed in Argas (Argas) striatus Bedford, 1932 and Argas (Secretargas) transgariepinus White, 1846. Ticks Tick Borne Dis 2018; 9:889-895. [PMID: 29598898 DOI: 10.1016/j.ttbdis.2018.03.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 02/20/2018] [Accepted: 03/19/2018] [Indexed: 11/19/2022]
Abstract
Maternal behaviour (carrying of larvae on the opisthosoma) in ticks has thus far only been observed in Antricola (Parantricola) marginatus and was considered a unique derived adaptation of this genus. The authors extend this observation to two additional argasid species, namely Argas (Argas) striatus and Argas (Secretargas) transgariepinus. In addition, brooding behaviour over eggs were observed with A. (S.) transgariepinus. Maternal behaviour may be an evolutionary adaptation to ecological challenges in habitats unsuited for larval survival and may be related to the presence of pulvilli in larvae. This adaptation might have been present in the ancestral tick lineage since pulvilli occur in all tick families, and may have been derived from a more ancient adaptation in chelicerates where maternal behaviour was common. Female A. (S.) transgariepinus also possess a unique area on their ventral abdomen that is absent in males and may be a unique adaptation for maternal behaviour in this species. Phylogenetic analysis of the 16S rRNA genes for both species indicate that they are unique lineages that group basal to other members of the Argas genus, supporting the possibility that they harbour ancestral traits for this group.
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Affiliation(s)
- Ronel Pienaar
- Epidemiology, Parasites and Vectors, Agricultural Research Council-Onderstepoort Veterinary Research, Onderstepoort 0110, South Africa.
| | - Daniel G de Klerk
- Epidemiology, Parasites and Vectors, Agricultural Research Council-Onderstepoort Veterinary Research, Onderstepoort 0110, South Africa
| | - John F Putterill
- Epidemiology, Parasites and Vectors, Agricultural Research Council-Onderstepoort Veterinary Research, Onderstepoort 0110, South Africa
| | - Ben J Mans
- Epidemiology, Parasites and Vectors, Agricultural Research Council-Onderstepoort Veterinary Research, Onderstepoort 0110, South Africa; Department of Life and Consumer Sciences, University of South Africa, South Africa.
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Schachat SR, Robbins RG, Goddard J. Color Patterning in Hard Ticks (Acari: Ixodidae). JOURNAL OF MEDICAL ENTOMOLOGY 2018; 55:1-13. [PMID: 29045683 DOI: 10.1093/jme/tjx173] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Indexed: 06/07/2023]
Abstract
Among the hard ticks (Acari: Ixodidae), many species in the section Metastriata have intricate ornamentation on the scutum that is often used as a taxonomic character. However, the biological function(s) of this ornamentation remains unknown. Here, we summarize the main functions of color patterns recognized in the animal kingdom-thermoregulation, aposematism, camouflage, aggregation, mate recognition, and sexual signaling-and evaluate the potential of each of these to explain ornamentation in hard ticks. We also note the challenges and uncertainties involved in interpreting ornamentation in ticks as well as potential approaches for future research.
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Affiliation(s)
- Sandra R Schachat
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Mississippi State, MS
- Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC
| | - Richard G Robbins
- Walter Reed Biosystematics Unit, Department of Entomology, Smithsonian Institution, MSC, Suitland, MD
| | - Jerome Goddard
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Mississippi State, MS
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parasitised feathered dinosaurs as revealed by Cretaceous amber assemblages. Nat Commun 2017; 8:1924. [PMID: 29233973 PMCID: PMC5727220 DOI: 10.1038/s41467-017-01550-z] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 09/27/2017] [Indexed: 11/08/2022] Open
Abstract
Ticks are currently among the most prevalent blood-feeding ectoparasites, but their feeding habits and hosts in deep time have long remained speculative. Here, we report direct and indirect evidence in 99 million-year-old Cretaceous amber showing that hard ticks and ticks of the extinct new family Deinocrotonidae fed on blood from feathered dinosaurs, non-avialan or avialan excluding crown-group birds. A †Cornupalpatum burmanicum hard tick is entangled in a pennaceous feather. Two deinocrotonids described as †Deinocroton draculi gen. et sp. nov. have specialised setae from dermestid beetle larvae (hastisetae) attached to their bodies, likely indicating cohabitation in a feathered dinosaur nest. A third conspecific specimen is blood-engorged, its anatomical features suggesting that deinocrotonids fed rapidly to engorgement and had multiple gonotrophic cycles. These findings provide insight into early tick evolution and ecology, and shed light on poorly known arthropod-vertebrate interactions and potential disease transmission during the Mesozoic.
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Oleaga A, Obolo-Mvoulouga P, Manzano-Román R, Pérez-Sánchez R. A proteomic insight into the midgut proteome of Ornithodoros moubata females reveals novel information on blood digestion in argasid ticks. Parasit Vectors 2017; 10:366. [PMID: 28764815 PMCID: PMC5540513 DOI: 10.1186/s13071-017-2300-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 07/18/2017] [Indexed: 11/16/2022] Open
Abstract
Background The argasid tick Ornithodoros moubata is the main African vector of the human relapsing fever agent Borrelia duttoni and the African swine fever virus. Together with saliva, the tick midgut forms part of the host-tick-pathogen interface, and numerous midgut proteins play key functions in the blood digestion-related process and the infection and transmission of pathogens. This work explores the composition of the midgut proteome of unfed and fed O. moubata females with the aim to complete the biological information already obtained from the midgut transcriptome and provide a more robust and comprehensive perspective of this biological system. Methods Midgut tissues taken from females before feeding and 48 h after feeding were subjected to LC/MS-MS analysis. After functional characterization and classification of the proteins identified, the differences in the proteome between unfed and fed females were analysed and discussed. Additionally, a detailed analysis of particular groups of proteins that are involved in the processes of nutrient digestion and responses to the oxidative stress was carried out. Results 1491 non-redundant tick proteins were identified: 1132 of them in the midgut of unfed ticks, 1138 in the midgut of fed ticks, and up to 779 shared by both physiological conditions. Overall, the comparative analysis of the midgut proteomes of O. moubata females before and after feeding did not reveal great differences in the number or class of proteins expressed, enzymatic composition or functional classification. Conclusions The hemoglobinolytic system in ixodids and argasids is very similar in spite of the fact that they display very different feeding and reproductive strategies. Although the main source of nutrients in ticks are proteins, lipids and carbohydrates also constitute significant nutritional sources and play an important part in the process of blood digestion. The genes and proteins involved in intracellular transport mechanisms, defensive responses, detoxifying responses and stress responses seem to be closely regulated, highlighting the complexity and importance of these processes in tick biology, which in turn assigns them a great interest as targets for therapeutic and immunological interventions. Electronic supplementary material The online version of this article (doi:10.1186/s13071-017-2300-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ana Oleaga
- Parasitology Laboratory, Institute of Natural Resources and Agrobiology (IRNASA, CSIC), Cordel de Merinas, 40-52, 37008, Salamanca, Spain.
| | - Prosper Obolo-Mvoulouga
- Parasitology Laboratory, Institute of Natural Resources and Agrobiology (IRNASA, CSIC), Cordel de Merinas, 40-52, 37008, Salamanca, Spain
| | - Raúl Manzano-Román
- Parasitology Laboratory, Institute of Natural Resources and Agrobiology (IRNASA, CSIC), Cordel de Merinas, 40-52, 37008, Salamanca, Spain
| | - Ricardo Pérez-Sánchez
- Parasitology Laboratory, Institute of Natural Resources and Agrobiology (IRNASA, CSIC), Cordel de Merinas, 40-52, 37008, Salamanca, Spain
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Mans BJ, de Castro MH, Pienaar R, de Klerk D, Gaven P, Genu S, Latif AA. Ancestral reconstruction of tick lineages. Ticks Tick Borne Dis 2016; 7:509-35. [DOI: 10.1016/j.ttbdis.2016.02.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 01/26/2016] [Accepted: 02/02/2016] [Indexed: 01/15/2023]
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Díaz-Martín V, Manzano-Román R, Obolo-Mvoulouga P, Oleaga A, Pérez-Sánchez R. Development of vaccines against Ornithodoros soft ticks: An update. Ticks Tick Borne Dis 2015; 6:211-20. [PMID: 25802033 DOI: 10.1016/j.ttbdis.2015.03.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 03/04/2015] [Accepted: 03/05/2015] [Indexed: 11/19/2022]
Abstract
Ticks are parasites of great medical and veterinary importance since they are vectors of numerous pathogens that affect humans, livestock and pets. Among the argasids, several species of the genus Ornithodoros transmit serious diseases such as tick-borne human relapsing fever (TBRF) and African Swine Fever (ASF). In particular, Ornithodoros erraticus is the main vector of these two diseases in the Mediterranean while O. moubata is the main vector in Africa. The presence of these Ornithodoros ticks in domestic and peridomestic environments may greatly hinder the eradication of TBRF and ASF from endemic areas. In addition, there is a constant threat of reintroduction and spreading of ASF into countries from where it has been eradicated (Spain and Portugal) or where it was never present (the Caucasus, Russia and Eastern Europe). In these countries, the presence of Ornithodoros vectors could have a tremendous impact on ASF transmission and long-term maintenance. Therefore, elimination of these ticks from at least synanthropic environments would contribute heavily to the prevention and control of the diseases they transmit. Tick control is a difficult task and although several methods for such control have been used, none of them has been fully effective against all ticks and the problems they cause. Nevertheless, immunological control using anti-tick vaccines offers an attractive alternative to the traditional use of acaricides. The aim of the present paper is to offer a brief overview of the current status in control measure development for Ornithodoros soft ticks, paying special attention to the development of vaccines against O. erraticus and O. moubata. Thus, our contribution includes an analysis of the chief attributes that the ideal antigens for an anti-tick vaccine should have, an exhaustive compilation and analysis of the scant anti-soft tick vaccine trials carried out to date using both concealed and salivary antigens and, finally, a brief description of the new reverse vaccinology approaches currently used to identify new and more effective protective tick antigens.
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Affiliation(s)
- Verónica Díaz-Martín
- Parasitología Animal, Instituto de Recursos Naturales y Agrobiología de Salamanca (IRNASA, CSIC), Cordel de Merinas, 40-52, 37008 Salamanca, Spain.
| | - Raúl Manzano-Román
- Parasitología Animal, Instituto de Recursos Naturales y Agrobiología de Salamanca (IRNASA, CSIC), Cordel de Merinas, 40-52, 37008 Salamanca, Spain.
| | - Prosper Obolo-Mvoulouga
- Parasitología Animal, Instituto de Recursos Naturales y Agrobiología de Salamanca (IRNASA, CSIC), Cordel de Merinas, 40-52, 37008 Salamanca, Spain.
| | - Ana Oleaga
- Parasitología Animal, Instituto de Recursos Naturales y Agrobiología de Salamanca (IRNASA, CSIC), Cordel de Merinas, 40-52, 37008 Salamanca, Spain.
| | - Ricardo Pérez-Sánchez
- Parasitología Animal, Instituto de Recursos Naturales y Agrobiología de Salamanca (IRNASA, CSIC), Cordel de Merinas, 40-52, 37008 Salamanca, Spain.
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Barker SC, Walker AR, Campelo D. A list of the 70 species of Australian ticks; diagnostic guides to and species accounts of Ixodes holocyclus (paralysis tick), Ixodes cornuatus (southern paralysis tick) and Rhipicephalus australis (Australian cattle tick); and consideration of the place of Australia in the evolution of ticks with comments on four controversial ideas. Int J Parasitol 2014; 44:941-53. [PMID: 25236960 DOI: 10.1016/j.ijpara.2014.08.008] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Revised: 08/08/2014] [Accepted: 08/11/2014] [Indexed: 11/25/2022]
Abstract
Seventy species of ticks are known from Australia: 14 soft ticks (family Argasidae) and 56 hard ticks (family Ixodidae). Sixteen of the 70 ticks in Australia may feed on humans and domestic animals (Barker and Walker 2014). The other 54 species of ticks in Australia feed only on wild mammals, reptiles and birds. At least 12 of the species of ticks in Australian also occur in Papua New Guinea. We use an image-matching system much like the image-matching systems of field guides to birds and flowers to identify Ixodes holocyclus (paralysis tick), Ixodes cornuatus (southern paralysis tick) and Rhipicephalus (Boophilus) australis (Australian cattle tick). Our species accounts have reviews of the literature on I. holocyclus (paralysis tick) from the first paper on the biology of an Australian tick by Bancroft (1884), on paralysis of dogs by I. holocyclus, to papers published recently, and of I. cornuatus (southern paralysis tick) and Rhipicephalus (Boophilus) australis (Australian cattle tick). We comment on four controversial questions in the evolutionary biology of ticks: (i) were labyrinthodont amphibians in Australia in the Devonian the first hosts of soft, hard and nuttalliellid ticks?; (ii) are the nuttalliellid ticks the sister-group to the hard ticks or the soft ticks?; (iii) is Nuttalliella namaqua the missing link between the soft and hard ticks?; and (iv) the evidence for a lineage of large bodied parasitiform mites (ticks plus the holothyrid mites plus the opiliocarid mites).
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Affiliation(s)
- Stephen C Barker
- Department of Parasitology, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Qld 4072, Australia.
| | - Alan R Walker
- Royal (Dick) School of Veterinary Studies, University of Edinburgh, EH25 9RG Scotland, United Kingdom
| | - Dayana Campelo
- Department of Parasitology, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Qld 4072, Australia
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Mans BJ, de Klerk DG, Pienaar R, Latif AA. The host preferences of Nuttalliella namaqua (Ixodoidea: Nuttalliellidae): a generalist approach to surviving multiple host-switches. EXPERIMENTAL & APPLIED ACAROLOGY 2014; 62:233-240. [PMID: 24057095 DOI: 10.1007/s10493-013-9737-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2013] [Accepted: 09/16/2013] [Indexed: 06/02/2023]
Abstract
Nuttalliella namaqua has been described as a "living fossil" and the closest extant species to the ancestral tick lineage. It was previously proposed that the Nuttalliella lineage parasitized reptile-like mammals in the Permian and had to switch hosts several times due to mass or host lineage extinctions. Extant hosts include girdled lizards and murid rodents. The current study extends knowledge on the extant host range of N. namaqua using gut meal analysis of field collected specimens. Nymphs and females can parasitize a variety of reptiles that includes skinks, geckos and girdled lizards. Blood-meal from a hyrax was also detected in a specimen suggesting that N. namaqua could parasitize a broader range of mammals than the previously suggested murid rodents. Rather than being host specific, N. namaqua is proposed to be a generalist and the ability to switch and parasitize multiple hosts allowed it to survive multiple mass and host lineage extinctions.
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Affiliation(s)
- Ben J Mans
- Parasites, Vectors and Vector-Borne Diseases, Agricultural Research Council, Onderstepoort Veterinary Institute, Onderstepoort, 0110, South Africa,
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Mans BJ, de Klerk D, Pienaar R, de Castro MH, Latif AA. The mitochondrial genomes of Nuttalliella namaqua (Ixodoidea: Nuttalliellidae) and Argas africolumbae (Ixodoidae: Argasidae): estimation of divergence dates for the major tick lineages and reconstruction of ancestral blood-feeding characters. PLoS One 2012; 7:e49461. [PMID: 23145176 PMCID: PMC3493528 DOI: 10.1371/journal.pone.0049461] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Accepted: 10/09/2012] [Indexed: 11/19/2022] Open
Abstract
Ixodida are composed of hard (Ixodidae), soft (Argasidae) and the monotypic Nuttalliellidae (Nuttalliella namaqua) tick families. Nuclear 18S rRNA analysis suggested that N. namaqua was the closest extant relative to the last common ancestral tick lineage. The mitochondrial genomes of N. namaqua and Argas africolumbae were determined using next generation sequencing and de novo assembly to investigate this further. The latter was included since previous estimates on the divergence times of argasids lacked data for this major genus. Mitochondrial gene order for both was identical to that of the Argasidae and Prostriata. Bayesian analysis of the COI, Cytb, ND1, ND2 and ND4 genes confirmed the monophyly of ticks, the basal position of N. namaqua to the other tick families and the accepted systematic relationships of the other tick genera. Molecular clock estimates were derived for the divergence of the major tick lineages and supported previous estimates on the origins of ticks in the Carboniferous. N. namaqua larvae fed successfully on lizards and mice in a prolonged manner similar to many argasids and all ixodids. Excess blood meal-derived water was secreted via the salivary glands, similar to ixodids. We propose that this prolonged larval feeding style eventually gave rise to the long feeding periods that typify the single larval, nymphal and adult stages of ixodid ticks and the associated secretion of water via the salivary glands. Ancestral reconstruction of characters involved in blood-feeding indicates that most of the characteristics unique to either hard or soft tick families were present in the ancestral tick lineage.
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Affiliation(s)
- Ben J Mans
- Parasites, Vectors and Vector-borne Diseases, Agricultural Research Council-Onderstepoort Veterinary Institute, Onderstepoort, South Africa.
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