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Busi A, Martínez-Sánchez ET, Alvarez-Londoño J, Rivera-Páez FA, Ramírez-Chaves HE, Fontúrbel FE, Castaño-Villa GJ. Environmental and ecological factors affecting tick infestation in wild birds of the Americas. Parasitol Res 2024; 123:254. [PMID: 38922478 PMCID: PMC11208200 DOI: 10.1007/s00436-024-08246-6] [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: 01/16/2024] [Accepted: 05/22/2024] [Indexed: 06/27/2024]
Abstract
The Americas hold the greatest bird diversity worldwide. Likewise, ectoparasite diversity is remarkable, including ticks of the Argasidae and Ixodidae families - commonly associated with birds. Considering that ticks have potential health implications for humans, animals, and ecosystems, we conducted a systematic review to evaluate the effects of bioclimatic, geographic variables, and bird species richness on tick infestation on wild birds across the Americas. We identified 72 articles that met our inclusion criteria and provided data on tick prevalence in wild birds. Using Generalized Additive Models, we assessed the effect of environmental factors, such as habitat type, climatic conditions, bird species richness, and geographic location, on tick infestation. Our findings show that most bird infestation case studies involved immature ticks, such as larvae or nymphs, while adult ticks represented only 13% of case studies. We found birds infested by ticks of the genera Amblyomma (68%), Ixodes (22%), Haemaphysalis (5%), Dermacentor (1%), and Rhipicephalus (0.8%) in twelve countries across the Americas. Our findings revealed that temperature variation and bird species richness were negatively associated with tick infestation, which also varied with geographic location, increasing in mid-latitudes but declining in extreme latitudes. Our results highlight the importance of understanding how environmental and bird community factors influence tick infestation in wild birds across the Americas and the dynamics of tick-borne diseases and their impact on biodiversity.
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Affiliation(s)
- Ana Busi
- Grupo de Investigación en Genética, Biodiversidad y Manejo de Ecosistemas (GEBIOME), Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad de Caldas, Calle 65 No. 26-10, 170004, Manizales, Caldas, Colombia
- Grupo de Investigación en Ecosistemas Tropicales, Facultad de Ciencias Exactas y Naturales, Universidad de Caldas, Calle 65 No. 26-10, 170004, Manizales, Caldas, Colombia
- Doctorado en Ciencias-Agrarias, Facultad de Ciencias Agropecuarias, Universidad de Caldas, Calle 64B No. 25-65, 170004, Manizales, Caldas, Colombia
| | - Estefani T Martínez-Sánchez
- Grupo de Investigación en Genética, Biodiversidad y Manejo de Ecosistemas (GEBIOME), Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad de Caldas, Calle 65 No. 26-10, 170004, Manizales, Caldas, Colombia
- Doctorado en Ciencias-Biología, Facultad de Ciencias Exactas y Naturales, Universidad de Caldas, Calle 65 No. 26-10, 170004, Manizales, Caldas, Colombia
| | - Johnathan Alvarez-Londoño
- Grupo de Investigación en Genética, Biodiversidad y Manejo de Ecosistemas (GEBIOME), Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad de Caldas, Calle 65 No. 26-10, 170004, Manizales, Caldas, Colombia
- Facultad de Ciencias Exactas y Naturales, Maestría en Ciencias Biológicas, Universidad de Caldas, Calle 65 No. 26-10, 170004, Manizales, Caldas, Colombia
| | - Fredy A Rivera-Páez
- Grupo de Investigación en Genética, Biodiversidad y Manejo de Ecosistemas (GEBIOME), Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad de Caldas, Calle 65 No. 26-10, 170004, Manizales, Caldas, Colombia
| | - Héctor E Ramírez-Chaves
- Grupo de Investigación en Genética, Biodiversidad y Manejo de Ecosistemas (GEBIOME), Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad de Caldas, Calle 65 No. 26-10, 170004, Manizales, Caldas, Colombia
- Centro de Museos, Museo de Historia Natural, Universidad de Caldas, Calle 58 No. 21-50, 170004, Manizales, Caldas, Colombia
| | - Francisco E Fontúrbel
- Instituto de Biología, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, 2373223, Valparaíso, Chile
| | - Gabriel J Castaño-Villa
- Grupo de Investigación en Genética, Biodiversidad y Manejo de Ecosistemas (GEBIOME), Facultad de Ciencias Agropecuarias, Universidad de Caldas, Calle 64B No. 25-65, 170004, Manizales, Caldas, Colombia.
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Bramlett KE, Witt LE, Meyer MM, Zellars K, Dye-Braumuller KC, Nolan MS. Evidence of Incomplete Feeding Behaviors among South Carolina Tick Populations. INSECTS 2024; 15:385. [PMID: 38921100 PMCID: PMC11203686 DOI: 10.3390/insects15060385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Revised: 05/20/2024] [Accepted: 05/22/2024] [Indexed: 06/27/2024]
Abstract
Dynamic environmental conditions, such as climate change and host availability, have greatly influenced the expansion of medically relevant tick vectors into new regions throughout the southeastern United States of America. As tick populations migrate into new areas, it has been suggested they can exhibit a phenomenon known as incomplete feeding. With this phenomenon, tick vectors feed on more than one host at each life stage, thus increasing the likelihood of pathogen transmission. Although this behavior is not well understood, it presents an important threat to human health. Here we present evidence of incomplete feeding behaviors in multiple tick species in South Carolina. Engorged, blood-fed female ticks were collected from feral dogs at animal shelters across South Carolina in 2022. All ticks were tested for human blood meals using rapid stain identification blood tests. Approximately one third (33.78%) of all ticks tested positive for a human blood meal, with various patterns seen across species, geographic location, and collection month. The results of this pilot study follow the current national trend of increasing rates of tick-borne disease incidence in the southeastern United States of America and warrant further investigation into the relationship between seasonality, geographic distribution, species, and incomplete feeding among tick populations in South Carolina.
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Affiliation(s)
- Kayla E. Bramlett
- Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208, USA; (K.E.B.); (L.E.W.); (M.M.M.); (K.Z.); (K.C.D.-B.)
| | - Laura E. Witt
- Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208, USA; (K.E.B.); (L.E.W.); (M.M.M.); (K.Z.); (K.C.D.-B.)
| | - Madeleine M. Meyer
- Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208, USA; (K.E.B.); (L.E.W.); (M.M.M.); (K.Z.); (K.C.D.-B.)
- Department of Environmental Health, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208, USA
| | - Kia Zellars
- Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208, USA; (K.E.B.); (L.E.W.); (M.M.M.); (K.Z.); (K.C.D.-B.)
| | - Kyndall C. Dye-Braumuller
- Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208, USA; (K.E.B.); (L.E.W.); (M.M.M.); (K.Z.); (K.C.D.-B.)
| | - Melissa S. Nolan
- Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208, USA; (K.E.B.); (L.E.W.); (M.M.M.); (K.Z.); (K.C.D.-B.)
- Institute for Infectious Disease Translational Research, University of South Carolina, Columbia, SC 29208, USA
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Ferguson LV, El Nabbout A, Adamo SA. Warming, but not infection with Borrelia burgdorferi, increases off-host winter activity in the ectoparasite, Ixodes scapularis. J Therm Biol 2024; 121:103853. [PMID: 38626664 DOI: 10.1016/j.jtherbio.2024.103853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Accepted: 03/17/2024] [Indexed: 04/18/2024]
Abstract
Warming winters will change patterns of behaviour in temperate and polar arthropods, but we know little about the drivers of winter activity in animals such as ticks. Any changes in behaviour are likely to arise from a combination of both abiotic (e.g. temperature) and biotic (e.g. infection) drivers, and will have important consequences for survival and species interactions. Blacklegged ticks, Ixodes scapularis, have invaded Atlantic Canada and high proportions (30-50%) are infected with the bacteria causing Lyme disease, Borrelia burgdorferi. Infection is correlated with increased overwintering survival of adult females, and ticks are increasingly active in the winter, but it is unclear if infection is associated with activity. Further, we know little about how temperature drives the frequency of winter activity. Here, we exposed wild-caught, adult, female Ixodes scapularis ticks to three different winter temperature regimes (constant low temperatures, increased warming, and increased warming + variability) to determine the thermal and infection conditions that promote or suppress activity. We used automated behaviour monitors to track daily activity in individual ticks and repeated the study with fresh ticks over three years. Following exposure to winter conditions we determined whether ticks were infected with the bacteria B. burgdorferi and if infection was responsible for any patterns in winter activity. Warming conditions promoted increased activity throughout the overwintering period but infection with B. burgdorferi had no impact on the frequency or overall number of ticks active throughout the winter. Individual ticks varied in their levels of activity throughout the winter, such that some were largely dormant for several weeks, while others were active almost daily; however, we do not yet know the drivers behind this individual variation in behaviour. Overall, warming winters will heighten the risk of tick-host encounters.
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Affiliation(s)
- Laura V Ferguson
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS, B3H 4J1, Canada.
| | - Amal El Nabbout
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS, B3H 4J1, Canada
| | - Shelley A Adamo
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS, B3H 4J1, Canada
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Lefcort H, Hovancsek ML, Bell LA, Ellinwood EK, Freisinger EM, Herrmann KG, Lau JR. Do ticks exhibit repeatable individual behaviors? EXPERIMENTAL & APPLIED ACAROLOGY 2023; 91:629-644. [PMID: 37921893 DOI: 10.1007/s10493-023-00850-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 10/05/2023] [Indexed: 11/05/2023]
Abstract
Diseases caused by ticks are often addressed as a traditional epidemiological mathematical puzzle, i.e., how many identical infected vectors, how many uniform potential hosts, and a dependable rate of transmission, etc. Although often useful at the population level, at the individual level disease transmission occurs when one tick bites one person. Just as we assign agency to people in their outdoor behavior and use of prophylactics against arthropods, perhaps we should also see ticks as individual actors? Are all ticks automatons that just quest and attach, or do they exhibit repeatable individual behaviors that affect transmission? We wanted to determine whether Dermacentor andersoni and D. variabilis adult ticks exhibited repeatable behaviors in four experiments. The experiments focused on left/right movement, attraction to CO2, photophilic tendencies, and avoidance of a repellant. We hypothesized that over two seasons we would find repeatable behavior patterns. In 2021, but not 2022, we found that within an experiment, individuals exhibited repeatable behaviors between trials and between experiments, i.e., if an animal showed repeatable 'adventurous' behavior in one experiment, this predicted adventurous behavior in a separate experiment. This strong evidence of predictable trait-like behavior was present in 2021 but was absent when we repeated the same experiments, with the same collection site, in 2022. This illustrates the importance of multiyear experimentation when testing for repeatable individual behaviors. Incidental to the study, we also observed that a major heat wave in 2021 altered the tick species composition (toward a more dry-adapted population) at our study site.
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Affiliation(s)
- Hugh Lefcort
- Biology Department, Gonzaga University, 502 E. Boone Avenue, Spokane, WA, 99258, USA.
| | - Matthew L Hovancsek
- Biology Department, Gonzaga University, 502 E. Boone Avenue, Spokane, WA, 99258, USA
| | - Lindsey A Bell
- Biology Department, Gonzaga University, 502 E. Boone Avenue, Spokane, WA, 99258, USA
| | - Erin K Ellinwood
- Biology Department, Gonzaga University, 502 E. Boone Avenue, Spokane, WA, 99258, USA
| | | | - Katelin G Herrmann
- Biology Department, Gonzaga University, 502 E. Boone Avenue, Spokane, WA, 99258, USA
| | - Jalisa R Lau
- Biology Department, Gonzaga University, 502 E. Boone Avenue, Spokane, WA, 99258, USA
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Bakker JW, Begemann HLM, Fonville M, Esser HJ, de Boer WF, Sprong H, Koenraadt CJM. Differential associations of horizontally and vertically transmitted symbionts on Ixodes ricinus behaviour and physiology. Parasit Vectors 2023; 16:443. [PMID: 38017525 PMCID: PMC10685571 DOI: 10.1186/s13071-023-06025-3] [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: 05/08/2023] [Accepted: 10/19/2023] [Indexed: 11/30/2023] Open
Abstract
BACKGROUND Ixodes ricinus ticks are infected with a large diversity of vertically and horizontally transmitted symbionts. While horizontally transmitted symbionts rely on a vertebrate host for their transmission, vertically transmitted symbionts rely more on the survival of their invertebrate host for transmission. We therefore hypothesized horizontally transmitted symbionts to be associated with increased tick activity to increase host contact rate and vertically transmitted symbionts to be associated with higher tick weight and lipid fraction to promote tick survival. METHODS We used a behavioural assay to record the questing activity of I. ricinus ticks. In addition, we measured weight and lipid fraction and determined the presence of ten symbiont species in these ticks using qPCR, of which six were vertically transmitted and four horizontally transmitted. RESULTS Vertically transmitted symbionts (e.g. Midichloria mitochondrii) were associated with an increase in tick weight, whereas horizontally transmitted symbionts (e.g. Borrelia burgdorferi sensu lato) were often associated with lower weight and lipid fraction of ticks. Moreover, horizontally transmitted symbionts (e.g. B. burgdorferi s.l.) were associated with increased tick activity, which may benefit pathogen transmission and increases tick-borne disease hazard. CONCLUSIONS Our study shows that horizontally and vertically transmitted symbionts differentially influence the behaviour and physiology of I. ricinus and warrants future research to study the underlying mechanisms and effects on transmission dynamics of tick-borne pathogens.
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Affiliation(s)
- Julian W Bakker
- Laboratory of Entomology, Wageningen University and Research, Wageningen, The Netherlands.
| | - Hannah L M Begemann
- Laboratory of Entomology, Wageningen University and Research, Wageningen, The Netherlands
| | - Manoj Fonville
- Centre for Infectious Disease Control, National Institute of Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - Helen J Esser
- Wildlife Ecology and Conservation Group, Wageningen University & Research, Wageningen, The Netherlands
| | - Willem F de Boer
- Wildlife Ecology and Conservation Group, Wageningen University & Research, Wageningen, The Netherlands
| | - Hein Sprong
- Centre for Infectious Disease Control, National Institute of Public Health and the Environment (RIVM), Bilthoven, The Netherlands
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McClung KL, Sundstrom KD, Lineberry MW, Grant AN, Little SE. Seasonality of Amblyomma americanum (Acari: Ixodidae) Activity and Prevalence of Infection with Tick-Borne Disease Agents in North Central Oklahoma. Vector Borne Zoonotic Dis 2023; 23:561-567. [PMID: 37668606 PMCID: PMC10654644 DOI: 10.1089/vbz.2023.0009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/06/2023] Open
Abstract
Background: Amblyomma americanum is the most common tick infesting both animals and humans in the southern United States and transmits a variety of zoonotic agents. The rise in tick-borne diseases (TBD) globally imparts a need for more active surveillance of tick populations to accurately quantify prevalence and risk of tick-borne infectious organisms. To better understand TBD risk in north central Oklahoma, this study aimed to describe the current seasonal activity of A. americanum in this region and investigate the seasonality of tick-borne infectious agents. Materials and Methods: Tick collections were performed twice a month for a duration of 2 years at a field site in Payne County, Oklahoma. Total nucleic acid was extracted from a subset of adult A. americanum and tested for Rickettsia spp., Ehrlichia spp., and Borrelia spp. using established PCR protocols. Results: Peak activity times for each life stage were observed, with adults primarily active 1 month earlier than historical seasonal trends describe, and male A. americanum active earlier in the year than female A. americanum. Rickettsia spp., Ehrlichia chaffeensis, Ehrlichia ewingii, and Borrelia lonestari were found in 26.4%, 6.1%, 2.5%, and 1.1% of adult A. americanum, respectively. No seasonal trend in spotted fever group Rickettsia spp. (SFGR) was observed in peak activity months. Conclusions: This study found an apparently shifting phenology for A. americanum adults in Oklahoma. While these results did not show a trend in SFGR, further investigation is needed to better understand the potential seasonality of infection prevalence within A. americanum across the expanding range of this vector, especially considering the extended activity of males in winter months.
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Affiliation(s)
- Kristin L. McClung
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Kellee D. Sundstrom
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Megan W. Lineberry
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, Stillwater, Oklahoma, USA
- Veterinary Medicine Research and Development, Zoetis, Kalamazoo, Michigan, USA
| | - Amber N. Grant
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Susan E. Little
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, Stillwater, Oklahoma, USA
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Martin AM, Buttke D, Raphael J, Taylor K, Maes S, Parise CM, Ginsberg HS, Cross PC. Deer management generally reduces densities of nymphal Ixodes scapularis, but not prevalence of infection with Borrelia burgdorferi sensu stricto. Ticks Tick Borne Dis 2023; 14:102202. [PMID: 37244157 PMCID: PMC11265508 DOI: 10.1016/j.ttbdis.2023.102202] [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: 01/03/2023] [Revised: 05/05/2023] [Accepted: 05/08/2023] [Indexed: 05/29/2023]
Abstract
Human Lyme disease-primarily caused by the bacterium Borrelia burgdorferi sensu stricto (s.s.) in North America-is the most common vector-borne disease in the United States. Research on risk mitigation strategies during the last three decades has emphasized methods to reduce densities of the primary vector in eastern North America, the blacklegged tick (Ixodes scapularis). Controlling white-tailed deer populations has been considered a potential method for reducing tick densities, as white-tailed deer are important hosts for blacklegged tick reproduction. However, the feasibility and efficacy of white-tailed deer management to impact acarological risk of encountering infected ticks (namely, density of host-seeking infected nymphs; DIN) is unclear. We investigated the effect of white-tailed deer density and management on the density of host-seeking nymphs and B. burgdorferi s.s. infection prevalence using surveillance data from eight national parks and park regions in the eastern United States from 2014-2022. We found that deer density was significantly positively correlated with the density of nymphs (nymph density increased by 49% with a 1 standard deviation increase in deer density) but was not strongly correlated with the prevalence of B. burgdorferi s.s. infection in nymphal ticks. Further, while white-tailed deer reduction efforts were followed by a decrease in the density of I. scapularis nymphs in parks, deer removal had variable effects on B. burgdorferi s.s. infection prevalence, with some parks experiencing slight declines and others slight increases in prevalence. Our findings suggest that managing white-tailed deer densities alone may not be effective in reducing DIN in all situations but may be a useful tool when implemented in integrated management regimes.
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Affiliation(s)
- Alynn M Martin
- Caesar Kleberg Wildlife Research Institute, Texas A&M University - Kingsville, Kingsville, TX, 78363, USA; US Geological Survey, Northern Rocky Mountain Science Center, 2327 University Way, Suite #2, Bozeman, MT, 59715 USA.
| | | | - Jordan Raphael
- US National Park Service, Fire Island National Seashore, Patchogue, NY, 11772 USA
| | - Kelsey Taylor
- US National Park Service, Fire Island National Seashore, Patchogue, NY, 11772 USA
| | - Sarah Maes
- Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Fort Collins, CO 80521
| | - Christina M Parise
- Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Fort Collins, CO 80521
| | - Howard S Ginsberg
- U.S. Geological Survey, Eastern Ecological Science Center, Woodward Hall-PSE, University of Rhode Island, Kingston, RI, 02881 USA
| | - Paul C Cross
- US Geological Survey, Northern Rocky Mountain Science Center, 2327 University Way, Suite #2, Bozeman, MT, 59715 USA
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Fountain-Jones NM, Khoo BS, Rau A, Berman JD, Burton EN, Oliver JD. Positive associations matter: Microbial relationships drive tick microbiome composition. Mol Ecol 2023. [PMID: 37173817 DOI: 10.1111/mec.16985] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 04/13/2023] [Accepted: 05/02/2023] [Indexed: 05/15/2023]
Abstract
Untangling how factors such as environment, host, associations among bacterial species and dispersal predict microbial composition is a fundamental challenge. In this study, we use complementary machine-learning approaches to quantify the relative role of these factors in shaping microbiome variation of the blacklegged tick Ixodes scapularis. I. scapularis is the most important vector for Borrelia burgdorferi (the causative agent for Lyme disease) in the U.S. as well as a range of other important zoonotic pathogens. Yet the relative role of the interactions between pathogens and symbionts compared to other ecological forces is unknown. We found that positive associations between microbes where the occurrence of one microbe increases the probability of observing another, including between both pathogens and symbionts, was by far the most important factor shaping the tick microbiome. Microclimate and host factors played an important role for a subset of the tick microbiome including Borrelia (Borreliella) and Ralstonia, but for the majority of microbes, environmental and host variables were poor predictors at a regional scale. This study provides new hypotheses on how pathogens and symbionts might interact within tick species, as well as valuable predictions for how some taxa may respond to changing climate.
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Affiliation(s)
| | - Benedict S Khoo
- School of Public Health, Division of Environmental Health Sciences, University of Minnesota, Minneapolis, Minnesota, USA
| | - Austin Rau
- School of Public Health, Division of Environmental Health Sciences, University of Minnesota, Minneapolis, Minnesota, USA
| | - Jesse D Berman
- School of Public Health, Division of Environmental Health Sciences, University of Minnesota, Minneapolis, Minnesota, USA
| | - Erin N Burton
- College of Veterinary Medicine, Veterinary and Biomedical Sciences, University of Minnesota, St. Paul, Minnesota, USA
| | - Jonathan D Oliver
- School of Public Health, Division of Environmental Health Sciences, University of Minnesota, Minneapolis, Minnesota, USA
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Lee X, Maxson GA, Paskewitz S. Single Mowing Event Does Not Reduce Abundance of Ixodes scapularis (Acari: Ixodidae) and Dermacentor variabilis (Acari: Ixodidae) on Recreational Hiking Trails. JOURNAL OF MEDICAL ENTOMOLOGY 2023; 60:228-234. [PMID: 36308319 DOI: 10.1093/jme/tjac164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Indexed: 06/16/2023]
Abstract
Nuisance and medically important ticks can be abundant in a variety of forested landscapes, including recreational parks. Strategies to reduce the abundance of host-seeking ticks in high-use areas within parks are limited. Mowing vegetation is a recommended method to control ticks, but few studies have evaluated the efficacy of this practice. The goal of this study was to determine if a single mowing event could reduce the abundance of host-seeking ticks on recreational trails. Ticks were collected by dragging trails at three recreational parks in northern Minnesota during June and July, 2021. A pre-intervention sample was taken followed by six consecutive weeks of tick sampling. We encountered a total of 3,456 ticks (2,459 Ixodes scapularis Say and 997 Dermacentor variabilis L.) during the 7-week study period. There were no significant differences in the abundance of I. scapularis (adults) or D. variabilis (adults only) between control and mown trail sections. Mowing was a significant predictor of nymphal I. scapularis abundance but trended towards more ticks in mown sections compared to controls. These results suggest that a single mowing intervention during early June is likely to be ineffective as a strategy to reduce the risk of human contacts with ticks on trails.
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Affiliation(s)
- Xia Lee
- Department of Entomology, College of Agricultural and Life Sciences, University of Wisconsin - Madison, 1630 Linden Drive, Madison, WI 53706, USA
| | | | - Susan Paskewitz
- Department of Entomology, College of Agricultural and Life Sciences, University of Wisconsin - Madison, 1630 Linden Drive, Madison, WI 53706, USA
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Hodosi R, Kazimirova M, Soltys K. What do we know about the microbiome of I. ricinus? Front Cell Infect Microbiol 2022; 12:990889. [PMID: 36467722 PMCID: PMC9709289 DOI: 10.3389/fcimb.2022.990889] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Accepted: 10/17/2022] [Indexed: 10/07/2023] Open
Abstract
I. ricinus is an obligate hematophagous parasitic arthropod that is responsible for the transmission of a wide range of zoonotic pathogens including spirochetes of the genus Borrelia, Rickettsia spp., C. burnetii, Anaplasma phagocytophilum and Francisella tularensis, which are part the tick´s microbiome. Most of the studies focus on "pathogens" and only very few elucidate the role of "non-pathogenic" symbiotic microorganisms in I. ricinus. While most of the members of the microbiome are leading an intracellular lifestyle, they are able to complement tick´s nutrition and stress response having a great impact on tick´s survival and transmission of pathogens. The composition of the tick´s microbiome is not consistent and can be tied to the environment, tick species, developmental stage, or specific organ or tissue. Ovarian tissue harbors a stable microbiome consisting mainly but not exclusively of endosymbiotic bacteria, while the microbiome of the digestive system is rather unstable, and together with salivary glands, is mostly comprised of pathogens. The most prevalent endosymbionts found in ticks are Rickettsia spp., Ricketsiella spp., Coxiella-like and Francisella-like endosymbionts, Spiroplasma spp. and Candidatus Midichloria spp. Since microorganisms can modify ticks' behavior, such as mobility, feeding or saliva production, which results in increased survival rates, we aimed to elucidate the potential, tight relationship, and interaction between bacteria of the I. ricinus microbiome. Here we show that endosymbionts including Coxiella-like spp., can provide I. ricinus with different types of vitamin B (B2, B6, B7, B9) essential for eukaryotic organisms. Furthermore, we hypothesize that survival of Wolbachia spp., or the bacterial pathogen A. phagocytophilum can be supported by the tick itself since coinfection with symbiotic Spiroplasma ixodetis provides I. ricinus with complete metabolic pathway of folate biosynthesis necessary for DNA synthesis and cell division. Manipulation of tick´s endosymbiotic microbiome could present a perspective way of I. ricinus control and regulation of spread of emerging bacterial pathogens.
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Affiliation(s)
- Richard Hodosi
- Department of Microbiology and Virology, Faculty of Natural Sciences, Comenius University in Bratislava, Bratislava, Slovakia
| | - Maria Kazimirova
- Institute of Zoology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Katarina Soltys
- Department of Microbiology and Virology, Faculty of Natural Sciences, Comenius University in Bratislava, Bratislava, Slovakia
- Comenius University Science Park, Comenius University in Bratislava, Bratislava, Slovakia
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11
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Samanta K, Azevedo JF, Nair N, Kundu S, Gomes-Solecki M. Infected Ixodes scapularis Nymphs Maintained in Prolonged Questing under Optimal Environmental Conditions for One Year Can Transmit Borrelia burgdorferi ( Borreliella genus novum) to Uninfected Hosts. Microbiol Spectr 2022; 10:e0137722. [PMID: 35862961 PMCID: PMC9431577 DOI: 10.1128/spectrum.01377-22] [Citation(s) in RCA: 4] [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: 04/18/2022] [Accepted: 06/26/2022] [Indexed: 11/28/2022] Open
Abstract
In recent decades, Lyme disease has been expanding to previous nonendemic areas. We hypothesized that infected I. scapularis nymphs that retain host-seeking behavior under optimal environmental conditions are fit to fulfil their transmission role in the enzootic cycle of B. burgdorferi. We produced nymphal ticks in the laboratory under controlled temperature (22-25°C), humidity (80-90%), and natural daylight cycle conditions to allow them to retain host-seeking/questing behavior for 1 year. We then analyzed differences in B. burgdorferi infection prevalence in questing and diapause nymphs at 6 weeks postmolting (prime questing) as well as differences in infection prevalence of questing nymphs maintained under prolonged environmental induced questing over 12 months (prolonged questing). Lastly, we analyzed the fitness of nymphal ticks subjected to prolonged questing in transmission of B. burgdorferi to naive mice over the course of the year. B. burgdorferi infected unfed I. scapularis nymphal ticks maintained under optimal environmental conditions in the laboratory not only survived for a year in a developmental state of prolonged questing (host-seeking), but they retained an infection prevalence sufficient to effectively fulfil transmission of B. burgdorferi to uninfected mice after tick challenge. Our study is important for understanding and modeling Lyme disease expansion into former nonendemic regions due to climate change. IMPORTANCE Lyme disease is rapidly spreading from its usual endemic areas in the Northeast, Midwest, and Midatlantic states into neighboring areas, which could be due to changing climate patterns. Our study shows that unfed I. scapularis nymphal ticks kept under optimal environmental conditions in the laboratory survived for a year while exhibiting aggressive host-seeking behavior, and they maintained a B. burgdorferi infection prevalence which was sufficient to infect naive reservoir hosts after tick challenge. Our study raises important questions regarding prolonged survival of B. burgdorferi infected host-seeking nymphal I. scapularis ticks that can potentially increase the risk of Lyme disease incidence, if conditions of temperature and humidity become amenable to the enzootic cycle of B. burgdorferi in regions currently classified as nonendemic.
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Affiliation(s)
- Kamalika Samanta
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Jose F. Azevedo
- Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Nisha Nair
- Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Suman Kundu
- Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Maria Gomes-Solecki
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, Tennessee, USA
- Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center, Memphis, Tennessee, USA
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12
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Exploring the effects of pathogen infection on tick behaviour from individuals to populations. Anim Behav 2022. [DOI: 10.1016/j.anbehav.2022.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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13
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Springer A, Jordan D, Glass A, Kahl O, Fingerle V, Girl P, Chitimia-Dobler L, Strube C. Borrelia Infections in Ageing Ticks: Relationship with Morphometric Age Ratio in Field-Collected Ixodes ricinus Nymphs. Microorganisms 2022; 10:microorganisms10010166. [PMID: 35056615 PMCID: PMC8778018 DOI: 10.3390/microorganisms10010166] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 01/05/2022] [Accepted: 01/11/2022] [Indexed: 02/06/2023] Open
Abstract
In Europe, Ixodes ricinus plays a major role as a vector of Borrelia burgdorferi sensu lato (s.l.) spirochaetes, the causative agents of Lyme borreliosis, among other pathogens. In unfed ticks, Borrelia spirochaetes experience prolonged nutrient restriction. However, only few studies exist with regard to Borrelia infections in unfed ticks of different physiological ages. Changing body dimensions of unfed ticks, due to the consumption of energy reserves, allow physiological age estimation. The present study investigated the relationship of morphometric age with Borrelia prevalence and spirochaete load in 1882 questing I. ricinus nymphs, collected at two different locations in northern Germany in 2020. In addition, Borrelia species composition was investigated by employing a reverse line blot (RLB) probe panel suitable for the detection of ten different B. burgdorferi s.l. species, as well as the relapsing-fever spirochaete B. miyamotoi. Overall, Borrelia prevalence was 25.8% (485/1882). Whilst there was no statistically significant difference in Borrelia prevalence between the different morphometric age groups, Borrelia infection intensity as determined by probe-based quantitative real-time PCR significantly declined with increasing morphometric age. Borrelia species differentiation by RLB was successful in 29.5% of positive ticks, and revealed B. afzelii as the dominating species (65.0% of the differentiated infections). Additionally, B. garinii, B. valaisiana, B. burgdorferi sensu stricto, B. spielmanii, and B. miyamotoi were detected.
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Affiliation(s)
- Andrea Springer
- Institute for Parasitology, Centre for Infection Medicine, University of Veterinary Medicine Hannover, 30559 Hanover, Germany; (A.S.); (D.J.); (A.G.)
| | - Daniela Jordan
- Institute for Parasitology, Centre for Infection Medicine, University of Veterinary Medicine Hannover, 30559 Hanover, Germany; (A.S.); (D.J.); (A.G.)
| | - Antje Glass
- Institute for Parasitology, Centre for Infection Medicine, University of Veterinary Medicine Hannover, 30559 Hanover, Germany; (A.S.); (D.J.); (A.G.)
| | - Olaf Kahl
- Tick-Radar GmbH, 10555 Berlin, Germany;
| | - Volker Fingerle
- National Reference Center for Borrelia, Bavarian Health and Food Safety Authority, 85764 Oberschleissheim, Germany;
| | - Philipp Girl
- Bundeswehr Institute of Microbiology, 80937 Munich, Germany; (P.G.); (L.C.-D.)
| | | | - Christina Strube
- Institute for Parasitology, Centre for Infection Medicine, University of Veterinary Medicine Hannover, 30559 Hanover, Germany; (A.S.); (D.J.); (A.G.)
- Correspondence: ; Tel.: +49-511-9538-711
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14
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Wechtaisong W, Bonnet SI, Chomel BB, Lien YY, Chuang ST, Tsai YL. Investigation of Transovarial Transmission of Bartonella henselae in Rhipicephalus sanguineus sensu lato Ticks Using Artificial Feeding. Microorganisms 2021; 9:microorganisms9122501. [PMID: 34946103 PMCID: PMC8705908 DOI: 10.3390/microorganisms9122501] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 11/25/2021] [Accepted: 11/30/2021] [Indexed: 11/16/2022] Open
Abstract
Bartonella henselae is a slow-growing, Gram-negative bacterium that causes cat scratch disease in humans. A transstadial transmission of the bacteria from larvae to nymphs of Rhipicephalus sanguineus sensu lato (s.l.) ticks, suspected to be a potential vector of the bacteria, has been previously demonstrated. The present study aims to investigate transovarial transmission of B. henselae from R. sanguineus s.l. adults to their instars. Adult ticks (25 males and 25 females) were fed through an artificial feeding system on B. henselae-infected goat blood for 14 days, and 300 larvae derived from the experimentally B. henselae-infected females were fed on noninfected goat blood for 7 days. Nested PCR and culture were used to detect and isolate B. henselae in ticks and blood samples. Bartonella henselae DNA was detected in midguts, salivary glands, and carcasses of the semi-engorged adults and pooled tick feces (during feeding and post-feeding periods). After the oviposition period, B. henselae DNA was detected in salivary glands of females (33.3%), but not in pooled eggs or larvae derived from the infected females. However, B. henselae DNA was detected by nested PCR from the blood sample during larval feeding, while no viable B. henselae was isolated by culture. According to our findings, following infected blood meal, B. henselae could remain in the tick midguts, move to other tissues including salivary glands, and then be shed through tick feces with limited persistency. The presence of bacterial DNA in the blood during larval feeding shows the possibility of transovarial transmission of B. henselae in R. sanguineus s.l. ticks.
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Affiliation(s)
- Wittawat Wechtaisong
- Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 912, Taiwan; (W.W.); (Y.-Y.L.)
| | - Sarah I. Bonnet
- Animal Health Department, INRAE, 37380 Nouzilly, France;
- Functional Genetics of Infectious Diseases Unit, Institut Pasteur, CNRS UMR 2000, Université de Paris, 75015 Paris, France
| | - Bruno B. Chomel
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, CA 95616, USA;
| | - Yi-Yang Lien
- Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 912, Taiwan; (W.W.); (Y.-Y.L.)
| | - Shih-Te Chuang
- Department of Veterinary Medicine, School of Veterinary Medicine, National Chung Hsing University, Taichung 402, Taiwan;
| | - Yi-Lun Tsai
- Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 912, Taiwan; (W.W.); (Y.-Y.L.)
- Correspondence: ; Tel.: +886-8-774-0226
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15
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Knoll S, Springer A, Hauck D, Schunack B, Pachnicke S, Fingerle V, Strube C. Distribution of Borrelia burgdorferi s.l. and Borrelia miyamotoi in Ixodes tick populations in Northern Germany, co-infections with Rickettsiales and assessment of potential influencing factors. MEDICAL AND VETERINARY ENTOMOLOGY 2021; 35:595-606. [PMID: 34180074 DOI: 10.1111/mve.12537] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 04/30/2021] [Accepted: 06/03/2021] [Indexed: 06/13/2023]
Abstract
To determine Borrelia spp. (Spirochaetales: Spirochaetaceae) prevalence and species distribution in Northern Germany, Ixodes ticks were sampled from April to October in 2018 and 2019 by the flagging method at three locations each in five regions. Analysis by quantitative real-time PCR of 3150 individual ticks revealed an overall prevalence of 30.6%, without significant differences between tick stages (31.7% positive adults, 28.6% positive nymphs). Significant differences were observed in seasonal infection rates, but not between regions, landscape types or sampling years. Analysis of co-infections with Rickettsiales indicated a negative association between Borrelia and Anaplasma phagocytophilum infection. The most frequent Borrelia species differentiated by Reverse Line Blot were B. afzelii and B. garinii/B. bavariensis, followed by B. valaisiana, B. burgdorferi sensu stricto, B. spielmanii and B. lusitaniae. Furthermore, B. miyamotoi was identified in 12.9% of differentiable samples. No effect of region nor landscape type on species composition was found, but significant variations in the distribution at the different sampling sites within a region were observed. The detected monthly fluctuations in prevalence and the differences in intra-regional Borrelia species distribution underline the importance of long-term and multi-location monitoring of Borrelia spp. in ticks as an essential part of public health assessment.
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Affiliation(s)
- S Knoll
- Institute for Parasitology, Centre for Infection Medicine, University of Veterinary Medicine Hannover, Hanover, Germany
| | - A Springer
- Institute for Parasitology, Centre for Infection Medicine, University of Veterinary Medicine Hannover, Hanover, Germany
| | - D Hauck
- Institute for Parasitology, Centre for Infection Medicine, University of Veterinary Medicine Hannover, Hanover, Germany
| | - B Schunack
- Bayer Animal Health GmbH (part of Elanco Animal Health), Leverkusen, Germany
| | - S Pachnicke
- Bayer Vital GmbH, Leverkusen, Germany
- Elanco Deutschland GmbH, Monheim, Germany
| | - V Fingerle
- National Reference Centre for Borrelia, Oberschleißheim, Germany
| | - C Strube
- Institute for Parasitology, Centre for Infection Medicine, University of Veterinary Medicine Hannover, Hanover, Germany
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16
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Javed N, Bhatti A, Paradkar PN. Advances in Understanding Vector Behavioural Traits after Infection. Pathogens 2021; 10:pathogens10111376. [PMID: 34832532 PMCID: PMC8621129 DOI: 10.3390/pathogens10111376] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Revised: 10/18/2021] [Accepted: 10/20/2021] [Indexed: 11/24/2022] Open
Abstract
Vector behavioural traits, such as fitness, host-seeking, and host-feeding, are key determinants of vectorial capacity, pathogen transmission, and epidemiology of the vector-borne disease. Several studies have shown that infection with pathogens can alter these behavioural traits of the arthropod vector. Here, we review relevant publications to assess how pathogens modulate the behaviour of mosquitoes and ticks, major vectors for human diseases. The research has shown that infection with pathogens alter the mosquito’s flight activity, mating, fecundity, host-seeking, blood-feeding, and adaptations to insecticide bed nets, and similarly modify the tick’s locomotion, questing heights, vertical and horizontal walks, tendency to overcome obstacles, and host-seeking ability. Although some of these behavioural changes may theoretically increase transmission potential of the pathogens, their effect on the disease epidemiology remains to be verified. This study will not only help in understanding virus–vector interactions but will also benefit in establishing role of these behavioural changes in improved epidemiological models and in devising new vector management strategies.
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Affiliation(s)
- Nouman Javed
- CSIRO Health & Biosecurity, Australian Centre for Diseases Preparedness, Geelong, VIC 3220, Australia;
- Institute for Intelligent Systems Research and Innovation (IISRI), Deakin University, Geelong, VIC 3220, Australia;
| | - Asim Bhatti
- Institute for Intelligent Systems Research and Innovation (IISRI), Deakin University, Geelong, VIC 3220, Australia;
| | - Prasad N. Paradkar
- CSIRO Health & Biosecurity, Australian Centre for Diseases Preparedness, Geelong, VIC 3220, Australia;
- Correspondence:
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17
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The effects of habitat type and pathogen infection on tick host-seeking behaviour. Parasitology 2021; 149:59-64. [PMID: 35184779 PMCID: PMC8862009 DOI: 10.1017/s0031182021001554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Tick-borne pathogens pose a significant risk to livestock, wildlife and public health. Host-seeking behaviours may depend on a combination of infection status and environmental factors. Here, we assessed the effects of habitat type and pathogen infection on host-seeking behaviour (questing) in the lone star tick, Amblyomma americanum. Ticks were collected using a tick drag from two different habitat types: xeric hammock and successional hardwood forests. Using a standardized assay, we recorded the likelihood of questing for each tick, the average height quested and total time spent questing and then tested each tick for the presence of Rickettsia spp. and Ehrlichia spp. using conventional polymerase chain reaction. We did not detect Ehrlichia in any ticks, although 30% tested positive for Rickettsia amblyommatis, a member of the Rickettsia spotted fever group. Ticks infected with R. amblyommatis spent less time questing compared to uninfected ticks, with infected ticks spending 85 s on average questing and uninfected ticks spending 112 s. Additionally, ticks collected from xeric hammock habitats spent over twice as long questing compared to ticks from successional hardwood forests. Ticks from xeric hammock spent 151 s on average questing while ticks from successional hardwood forest spent only 58 s during a 10-min observation period. These results demonstrate that habitat type and infection status can influence tick host-seeking behaviours, which can play a pivotal role in disease dynamics.
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18
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Infection with Borrelia afzelii and manipulation of the egg surface microbiota have no effect on the fitness of immature Ixodes ricinus ticks. Sci Rep 2021; 11:10686. [PMID: 34021230 PMCID: PMC8140075 DOI: 10.1038/s41598-021-90177-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Accepted: 04/29/2021] [Indexed: 12/20/2022] Open
Abstract
Arthropod vectors carry vector-borne pathogens that cause infectious disease in vertebrate hosts, and arthropod-associated microbiota, which consists of non-pathogenic microorganisms. Vector-borne pathogens and the microbiota can both influence the fitness of their arthropod vectors, and hence the epidemiology of vector-borne diseases. The bacterium Borrelia afzelii, which causes Lyme borreliosis in Europe, is transmitted among vertebrate reservoir hosts by Ixodes ricinus ticks, which also harbour a diverse microbiota of non-pathogenic bacteria. The purpose of this controlled study was to test whether B. afzelii and the tick-associated microbiota influence the fitness of I. ricinus. Eggs obtained from field-collected adult female ticks were surface sterilized (with bleach and ethanol), which reduced the abundance of the bacterial microbiota in the hatched I. ricinus larvae by 28-fold compared to larvae that hatched from control eggs washed with water. The dysbiosed and control larvae were subsequently fed on B. afzelii-infected or uninfected control mice, and the engorged larvae were left to moult into nymphs under laboratory conditions. I. ricinus larvae that fed on B. afzelii-infected mice had a significantly faster larva-to-nymph moulting time compared to larvae that fed on uninfected control mice, but the effect was small (2.4% reduction) and unlikely to be biologically significant. We found no evidence that B. afzelii infection or reduction of the larval microbiota influenced the four other life history traits of the immature I. ricinus ticks, which included engorged larval weight, unfed nymphal weight, larva-to-nymph moulting success, and immature tick survival. A retrospective power analysis found that our sampling effort had sufficient power (> 80%) to detect small effects (differences of 5% to 10%) of our treatments. Under the environmental conditions of this study, we conclude that B. afzelii and the egg surface microbiota had no meaningful effects on tick fitness and hence on the R0 of Lyme borreliosis.
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19
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Bregnard C, Rais O, Voordouw MJ. Masting by beech trees predicts the risk of Lyme disease. Parasit Vectors 2021; 14:168. [PMID: 33743800 PMCID: PMC7980658 DOI: 10.1186/s13071-021-04646-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 02/16/2021] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND The incidence of Lyme borreliosis and other tick-borne diseases is increasing in Europe and North America. There is currently much interest in identifying the ecological factors that determine the density of infected ticks as this variable determines the risk of Lyme borreliosis to vertebrate hosts, including humans. Lyme borreliosis is caused by the bacterium Borrelia burgdorferi sensu lato (s.l.) and in western Europe, the hard tick Ixodes ricinus is the most important vector. METHODS Over a 15-year period (2004-2018), we monitored the monthly abundance of I. ricinus ticks (nymphs and adults) and their B. burgdorferi s.l. infection status at four different elevations on a mountain in western Switzerland. We collected climate variables in the field and from nearby weather stations. We obtained data on beech tree seed production (masting) from the literature, as the abundance of Ixodes nymphs can increase dramatically 2 years after a masting event. We used generalized linear mixed effects models and AIC-based model selection to identify the ecological factors that influence inter-annual variation in the nymphal infection prevalence (NIP) and the density of infected nymphs (DIN). RESULTS We found that the NIP decreased by 78% over the study period. Inter-annual variation in the NIP was explained by the mean precipitation in the present year, and the duration that the DNA extraction was stored in the freezer prior to pathogen detection. The DIN decreased over the study period at all four elevation sites, and the decrease was significant at the top elevation. Inter-annual variation in the DIN was best explained by elevation site, year, beech tree masting index 2 years prior and the mean relative humidity in the present year. This is the first study in Europe to demonstrate that seed production by deciduous trees influences the density of nymphs infected with B. burgdorferi s.l. and hence the risk of Lyme borreliosis. CONCLUSIONS Public health officials in Europe should be aware that masting by deciduous trees is an important predictor of the risk of Lyme borreliosis.
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Affiliation(s)
- Cindy Bregnard
- Laboratory of Ecology and Evolution of Parasites, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Olivier Rais
- Laboratory of Ecology and Epidemiology of Parasites, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Maarten Jeroen Voordouw
- Laboratory of Ecology and Evolution of Parasites, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
- Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada
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20
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Lefcort H, Tsybulnik DY, Browning RJ, Eagle HP, Eggleston TE, Magori K, Andrade CC. Behavioral characteristics and endosymbionts of two potential tularemia and Rocky Mountain spotted fever tick vectors. JOURNAL OF VECTOR ECOLOGY : JOURNAL OF THE SOCIETY FOR VECTOR ECOLOGY 2020; 45:321-332. [PMID: 33207056 DOI: 10.1111/jvec.12403] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 08/25/2020] [Indexed: 06/11/2023]
Abstract
Due to climate change-induced alterations of temperature and humidity, the distribution of pathogen-carrying organisms such as ticks may shift. Tick survival is often limited by environmental factors such as dryness, but a predicted hotter and wetter world may allow the expansion of tick ranges. Dermacentor andersoni and D. variabilis ticks are morphologically similar, co-occur throughout the Inland Northwest of Washington State, U.S.A., and both can be injected with pathogenic Rickettsia and Francisella bacteria. Differences in behavior and the potential role of endosymbiotic Rickettsia and Francisella in these ticks are poorly studied. We wanted to measure behavioral and ecological differences between the two species and determine which, if any, Rickettsia and Francisella bacteria - pathogenic or endosymbiotic - they carried. Additionally, we wanted to determine if either tick species may be selected for if the climate in eastern Washington becomes wetter or dryer. We found that D. andersoni is more resistant to desiccation, but both species share similar questing behaviors such as climbing and attraction to bright light. Both also avoid the odor of eucalyptus and DEET but not permethrin. Although both tick species are capable of transmitting pathogenic species of Francisella and Rickettsia, which cause tularemia and Rocky Mountain Spotted Fever, respectively, we found primarily non-pathogenic endosymbiotic strains of Francisella and Rickettsia, and only one tick infected with F. tularensis subspecies holarctica.
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Affiliation(s)
- Hugh Lefcort
- Biology Department, Gonzaga University, Spokane, WA, 99258
| | | | | | | | | | - Krisztian Magori
- Department of Biology, Eastern Washington University, Cheney, WA, 99004
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21
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Nyrhilä S, Sormunen JJ, Mäkelä S, Sippola E, Vesterinen EJ, Klemola T. One out of ten: low sampling efficiency of cloth dragging challenges abundance estimates of questing ticks. EXPERIMENTAL & APPLIED ACAROLOGY 2020; 82:571-585. [PMID: 33128644 PMCID: PMC7686165 DOI: 10.1007/s10493-020-00564-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 10/21/2020] [Indexed: 06/11/2023]
Abstract
Hard ticks (Acari: Ixodidae) act as important vectors of zoonotic pathogens. For instance, Borrelia burgdorferi s.l. spirochetes pose a severe health risk as aetiological agents of Lyme borreliosis. Commonly, to study the abundance of questing (host-seeking) ticks, a 1 m2 piece of cloth is dragged over vegetation for a determined distance. Here, we designed a tick-sampling study to estimate the sampling efficiency of this standard method. We established 10 m dragging transects in a hemiboreal mixed forest patch in SW Finland for a 5-day monitoring period. Five of the transects were cloth-dragged 3× a day, whereas another five transects were dragged 6× a day in a manner that after each morning, midday and afternoon dragging, a second dragging was conducted on the same transect immediately. Captured Ixodes ricinus ticks were subsequently analysed for tick-borne pathogens. The initial population size of nymphal ticks on a transect was approximated by the accumulated nymph catch from the dragging sessions. The sampling efficiency of the cloth dragging was low, as a single dragging in a previously untouched vegetation strip always caught less than 12% (mean 6%) of the estimated population of active nymphs that were assumed to be questing during the study. Clear results were not found for daily activity rhythm, as ticks were caught in all daily dragging sessions. Approximately every third nymph and every second adult carried a pathogen, but nothing indicated that the occurrence of a pathogen affected the likelihood of the tick being caught by cloth dragging. Our results suggest that only a minority of active ticks can be caught by a single cloth dragging. The abundance estimates in many tick investigations might thus be downward biased.
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Affiliation(s)
- Siiri Nyrhilä
- Department of Biology, University of Turku, FI-20014, Turku, Finland
| | - Jani J Sormunen
- Department of Biology, University of Turku, FI-20014, Turku, Finland
- Biodiversity Unit, University of Turku, Turku, Finland
| | - Satu Mäkelä
- Department of Biology, University of Turku, FI-20014, Turku, Finland
| | - Ella Sippola
- Department of Biology, University of Turku, FI-20014, Turku, Finland
- Biodiversity Unit, University of Turku, Turku, Finland
| | - Eero J Vesterinen
- Department of Biology, University of Turku, FI-20014, Turku, Finland
- Biodiversity Unit, University of Turku, Turku, Finland
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Tero Klemola
- Department of Biology, University of Turku, FI-20014, Turku, Finland.
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22
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Tick populations from endemic and non-endemic areas in Germany show differential susceptibility to TBEV. Sci Rep 2020; 10:15478. [PMID: 32968088 PMCID: PMC7511395 DOI: 10.1038/s41598-020-71920-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 08/20/2020] [Indexed: 12/17/2022] Open
Abstract
Tick-borne encephalitis virus (TBEV) is endemic in twenty-seven European countries, transmitted via the bite of an infected tick. TBEV is the causative agent of one of the most important viral diseases of the central nervous system (CNS). In Germany, 890 human cases were registered between the years 2018–2019. The castor bean tick, Ixodes ricinus, is the TBEV vector with the highest importance in Central Europe, including Germany. Despite the nationwide distribution of this tick species, risk areas of TBEV are largely located in Southern Germany. To increase our understanding of TBEV-tick interactions, we collected ticks from different areas within Germany (Haselmühl/Bavaria, Hanover/Lower Saxony) and infected them via an in vitro feeding system. A TBEV isolate was obtained from an endemic focus in Haselmühl. In two experimental series conducted in 2018 and 2019, ticks sampled in Haselmühl (TBEV focus) showed higher artificial feeding rates, as well as higher TBEV infections rates than ticks from the non-endemic area (Hanover). Other than the tick origin, year and month of the infection experiment as well as co-infection with Borrelia spp., had a significant impact on TBEV Haselmühl infection rates. Taken together, these findings suggest that a specific adaptation of the tick populations to their respective TBEV virus isolates or vice versa, leads to higher TBEV infection rates in those ticks. Furthermore, co-infection with other tick-borne pathogens such as Borrelia spp. can lower TBEV infection rates in specific populations.
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Benelli G. Pathogens Manipulating Tick Behavior-Through a Glass, Darkly. Pathogens 2020; 9:pathogens9080664. [PMID: 32824571 PMCID: PMC7459789 DOI: 10.3390/pathogens9080664] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 08/05/2020] [Accepted: 08/11/2020] [Indexed: 12/11/2022] Open
Abstract
Pathogens can manipulate the phenotypic traits of their hosts and vectors, maximizing their own fitness. Among the phenotypic traits that can be modified, manipulating vector behavior represents one of the most fascinating facets. How pathogens infection affects behavioral traits of key insect vectors has been extensively investigated. Major examples include Plasmodium, Leishmania and Trypanosoma spp. manipulating the behavior of mosquitoes, sand flies and kissing bugs, respectively. However, research on how pathogens can modify tick behavior is patchy. This review focuses on current knowledge about the behavioral changes triggered by Anaplasma, Borrelia, Babesia, Bartonella, Rickettsia and tick-borne encephalitis virus (TBEV) infection in tick vectors, analyzing their potential adaptive significance. As a general trend, being infected by Borrelia and TBEV boosts tick mobility (both questing and walking activity). Borrelia and Anaplasma infection magnifies Ixodes desiccation resistance, triggering physiological changes (Borrelia: higher fat reserves; Anaplasma: synthesis of heat shock proteins). Anaplasma infection also improves cold resistance in infected ticks through synthesis of an antifreeze glycoprotein. Being infected by Anaplasma, Borrelia and Babesia leads to increased tick survival. Borrelia, Babesia and Bartonella infection facilitates blood engorgement. In the last section, current challenges for future studies are outlined.
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Affiliation(s)
- Giovanni Benelli
- Department of Agriculture, Food and Environment, University of Pisa, via del Borghetto 80, 56124 Pisa, Italy
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Stewart PE, Bloom ME. Sharing the Ride: Ixodes scapularis Symbionts and Their Interactions. Front Cell Infect Microbiol 2020; 10:142. [PMID: 32322563 PMCID: PMC7156593 DOI: 10.3389/fcimb.2020.00142] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 03/18/2020] [Indexed: 12/15/2022] Open
Abstract
The deer tick Ixodes scapularis transmits a variety of disease agents in the United States, spreading the bacteria that causes Lyme borreliosis, the protozoan agent of babesiosis, and viruses such as Powassan. However, a variety of other organisms have also evolved symbiotic relationships with this tick species, and it seems likely that some of these microbes have simultaneously coevolved mechanisms to impact each other and their tick host. The number of organisms identified as I. scapularis symbionts has increased seemingly exponentially with the advent of PCR and next generation sequencing technologies, but convincing arguments have proposed that some of these are of environmental origin, unadapted to surviving the physiological conditions of the tick or that they are artifacts of ultrasensitive detection methods. In this review, we examine the diversity of the known microbes occurring within the I. scapularis microbiome, the evidence for interactions between microbes, and discuss whether some organisms reported to be symbionts of I. scapularis are experimental artifacts.
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Affiliation(s)
- Philip E Stewart
- Biology of Vector-Borne Viruses Section, Laboratory of Virology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, United States
| | - Marshall E Bloom
- Biology of Vector-Borne Viruses Section, Laboratory of Virology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, United States
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Couper LI, Yang Y, Yang XF, Swei A. Comparative vector competence of North American Lyme disease vectors. Parasit Vectors 2020; 13:29. [PMID: 31937369 PMCID: PMC6961398 DOI: 10.1186/s13071-020-3893-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 01/07/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Understanding the drivers of Lyme disease incidence at broad spatial scales is critical for predicting and mitigating human disease risk. Previous studies have identified vector phenology and behavior, host community composition, and landscape features as drivers of variable Lyme disease risk. However, while the Lyme disease transmission cycles in the eastern and western USA involve different vector species (Ixodes scapularis and Ixodes pacificus, respectively), the role of vector-specific differences in transmission efficiency has not been directly examined. By comparing the performance of traits involved in vector competence between these two species, this study aims to identify how vector competence contributes to variable Lyme disease risk. METHODS We used a suite of laboratory experiments to compare the performance of traits related to vector competence for the two USA Lyme disease vectors. For each species, we measured the rate of attachment to a common rodent host, the engorgement weight, and the efficiency of pathogen acquisition (host to tick) and pathogen transmission (tick to host) from laboratory mice. In measuring pathogen acquisition and transmission, we used two different pathogen strains, one sympatric with I. scapularis and one sympatric with I. pacificus, to assess the importance of vector-pathogen coevolutionary history in transmission dynamics. RESULTS We found I. pacificus had significantly higher host attachment success and engorgement weights, but significantly lower pathogen transmission efficiency relative to I. scapularis. Molting success and pathogen acquisition did not differ between these two species. However, pathogen acquisition efficiency was significantly higher for both sympatric vector and pathogen strains than the allopatric pairings. CONCLUSIONS This study identified species-specific vector traits as a potential driver of broad scale variation in Lyme disease risk in the USA. In particular, the exceedingly low rates of pathogen transmission from tick to host observed for I. pacificus may limit Lyme disease transmission efficiency in the western USA. Further, observed variation in pathogen acquisition between sympatric and allopatric vector-pathogen strains indicate that vector-pathogen coevolutionary history may play a key role in transmission dynamics. These findings underscore the need to consider vector traits and vector-pathogen coevolution as important factors governing regional Lyme disease risk.
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Affiliation(s)
- Lisa I Couper
- Department of Biology, Stanford University, Stanford, CA, USA
| | - Youyun Yang
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Xiaofeng Frank Yang
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Andrea Swei
- Department of Biology, San Francisco State University, San Francisco, CA, USA.
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Transcriptome Response of Female Culicoides sonorensis Biting Midges (Diptera: Ceratopogonidae) to Early Infection with Epizootic Hemorrhagic Disease Virus (EHDV-2). Viruses 2019; 11:v11050473. [PMID: 31137627 PMCID: PMC6563219 DOI: 10.3390/v11050473] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 05/20/2019] [Accepted: 05/22/2019] [Indexed: 12/13/2022] Open
Abstract
Female Culicoides sonorensis biting midges are vectors of epizootic hemorrhagic disease virus (EHDV), which causes morbidity and mortality in wild and domesticated ruminants. The aims in this study were to identify key changes in female midge transcriptome profiles occurring during early infection with EHDV-2. Midges were fed either negative control bloodmeals or bloodmeals containing EHDV-2 and transcriptomes were acquired at 36 h through deep sequencing. Reads were de novo assembled into a transcriptome comprised of 18,754 unigenes. Overall, there were 2401 differentially expressed unigenes and ~60% were downregulated in response to the virus (953 up; 1448 down). Downstream Gene Ontology enrichment, KEGG pathway mapping, and manual analyses were used to identify the effect of virus ingestion at both the gene and pathway levels. Downregulated unigenes were predominantly assigned to pathways related to cell/tissue structure and integrity (actin cytoskeleton, adherens junction, focal adhesion, hippo signaling), calcium signaling, eye morphogenesis and axon guidance. Unigenes attributed to sensory functions (especially vision), behavior, learning and memory were largely downregulated. Upregulated unigenes included those coding for innate immune processes, olfaction and photoreceptor pigments. Our results suggest that midges respond to virus infection as soon as 36 h post-ingestion, and that EHDV-2 may have a significant phenotypic effect on sensory and neural tissues.
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James CA, Pearl DL, Lindsay LR, Peregrine AS, Jardine CM. Risk factors associated with the carriage of Ixodes scapularis relative to other tick species in a population of pet dogs from southeastern Ontario, Canada. Ticks Tick Borne Dis 2019; 10:290-298. [DOI: 10.1016/j.ttbdis.2018.10.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 09/16/2018] [Accepted: 10/15/2018] [Indexed: 01/17/2023]
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Cabezas-Cruz A, Estrada-Peña A, Rego ROM, De la Fuente J. Tick-Pathogen Ensembles: Do Molecular Interactions Lead Ecological Innovation? Front Cell Infect Microbiol 2017; 7:74. [PMID: 28348982 PMCID: PMC5346557 DOI: 10.3389/fcimb.2017.00074] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 02/27/2017] [Indexed: 11/18/2022] Open
Affiliation(s)
- Alejandro Cabezas-Cruz
- UMR BIPAR, Animal Health Laboratory, ANSES, Institut National de la Recherche Agronomique, ENVAMaisons Alfort, France; Department of Parasitology, Faculty of Science, University of South BohemiaČeské Budějovice, Czechia; Biology Center, Institute of Parasitology, Czech Academy of SciencesČeské Budějovice, Czechia
| | | | - Ryan O M Rego
- Department of Parasitology, Faculty of Science, University of South BohemiaČeské Budějovice, Czechia; Biology Center, Institute of Parasitology, Czech Academy of SciencesČeské Budějovice, Czechia
| | - José De la Fuente
- SaBio. Instituto de Investigación en Recursos Cinegéticos IREC (CSIC-UCLM-JCCM)Ciudad Real, Spain; Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State UniversityStillwater, OK, USA
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Burtis JC, Sullivan P, Levi T, Oggenfuss K, Fahey TJ, Ostfeld RS. The impact of temperature and precipitation on blacklegged tick activity and Lyme disease incidence in endemic and emerging regions. Parasit Vectors 2016; 9:606. [PMID: 27887625 PMCID: PMC5124264 DOI: 10.1186/s13071-016-1894-6] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 11/18/2016] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND The incidence of Lyme disease shows high degrees of inter-annual variation in the northeastern United States, but the factors driving this variation are not well understood. Complicating matters, it is also possible that these driving factors may vary in regions with differing histories of Lyme disease endemism. We evaluated the effect of the number of hot (T > 25 °C), dry (precipitation = 0) days during the questing periods of the two immature Ixodes scapularis life stages (larval and nymphal) on inter-annual variation in Lyme disease incidence between 2000 and 2011 in long-term endemic versus recently endemic areas. We also evaluated the effect of summer weather on tick questing activity and the number of ticks found on small mammals between 1994 and 2012 on six sites in Millbrook, NY. RESULTS The number of hot, dry days during the larval period of the previous year did not affect the human incidence of Lyme disease or the density of questing nymphs the following season. However, dry summer weather during the nymphal questing period had a significant negative effect on the incidence of Lyme disease in the long-term endemic areas, and on the density of questing nymphs. Summer weather conditions had a more pronounced effect on actively questing I. scapularis collected via dragging than on the number of ticks found feeding on small mammals. In recently endemic areas Lyme disease incidence increased significantly over time, but no trend was detected between disease incidence and dry summer weather. CONCLUSIONS Recently endemic regions showed an increase in Lyme disease incidence over time, while incidence in long-term endemic regions appears to have stabilized. Only within the stabilized areas were we able to detect reduced Lyme disease incidence in years with hot, dry summer weather. These patterns were reflected in our field data, which showed that questing activity of nymphal I. scapularis was reduced by hot, dry summer weather.
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Affiliation(s)
- James C Burtis
- Department of Natural Resources, Cornell University, Fernow Hall, Ithaca, NY, USA.
| | - Patrick Sullivan
- Department of Natural Resources, Cornell University, Fernow Hall, Ithaca, NY, USA
| | - Taal Levi
- Department of Fisheries and Wildlife, Oregon State University, Corvallis, OR, USA
| | - Kelly Oggenfuss
- Cary Institute of Ecosystem Studies, 2801 Sharon Turnpike, Millbrook, NY, USA
| | - Timothy J Fahey
- Department of Natural Resources, Cornell University, Fernow Hall, Ithaca, NY, USA
| | - Richard S Ostfeld
- Cary Institute of Ecosystem Studies, 2801 Sharon Turnpike, Millbrook, NY, USA
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Zolnik CP, Prill RJ, Falco RC, Daniels TJ, Kolokotronis SO. Microbiome changes through ontogeny of a tick pathogen vector. Mol Ecol 2016; 25:4963-77. [DOI: 10.1111/mec.13832] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 08/19/2016] [Accepted: 08/29/2016] [Indexed: 01/03/2023]
Affiliation(s)
- Christine P. Zolnik
- Department of Biological Sciences; Fordham University; 441 East Fordham Road Bronx NY 10458 USA
- Vector Ecology Laboratory; Louis Calder Center-Biological Field Station; Fordham University; 53 Whippoorwill Road Armonk NY 10504 USA
| | - Robert J. Prill
- IBM Almaden Research Center; 650 Harry Road San Jose CA 95120 USA
| | - Richard C. Falco
- New York State Department of Health; Louis Calder Center-Biological Field Station; Fordham University; 53 Whippoorwill Road Armonk NY 10504 USA
| | - Thomas J. Daniels
- Vector Ecology Laboratory; Louis Calder Center-Biological Field Station; Fordham University; 53 Whippoorwill Road Armonk NY 10504 USA
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Esteve-Gassent MD, Castro-Arellano I, Feria-Arroyo TP, Patino R, Li AY, Medina RF, Pérez de León AA, Rodríguez-Vivas RI. TRANSLATING ECOLOGY, PHYSIOLOGY, BIOCHEMISTRY, AND POPULATION GENETICS RESEARCH TO MEET THE CHALLENGE OF TICK AND TICK-BORNE DISEASES IN NORTH AMERICA. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2016; 92:38-64. [PMID: 27062414 PMCID: PMC4844827 DOI: 10.1002/arch.21327] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 02/20/2016] [Indexed: 06/05/2023]
Abstract
Emerging and re-emerging tick-borne diseases threaten public health and the wellbeing of domestic animals and wildlife globally. The adoption of an evolutionary ecology framework aimed to diminish the impact of tick-borne diseases needs to be part of strategies to protect human and animal populations. We present a review of current knowledge on the adaptation of ticks to their environment, and the impact that global change could have on their geographic distribution in North America. Environmental pressures will affect tick population genetics by selecting genotypes able to withstand new and changing environments and by altering the connectivity and isolation of several tick populations. Research in these areas is particularly lacking in the southern United States and most of Mexico with knowledge gaps on the ecology of these diseases, including a void in the identity of reservoir hosts for several tick-borne pathogens. Additionally, the way in which anthropogenic changes to landscapes may influence tick-borne disease ecology remains to be fully understood. Enhanced knowledge in these areas is needed in order to implement effective and sustainable integrated tick management strategies. We propose to refocus ecology studies with emphasis on metacommunity-based approaches to enable a holistic perspective addressing whole pathogen and host assemblages. Network analyses could be used to develop mechanistic models involving multihost-pathogen communities. An increase in our understanding of the ecology of tick-borne diseases across their geographic distribution will aid in the design of effective area-wide tick control strategies aimed to diminish the burden of pathogens transmitted by ticks.
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Affiliation(s)
- Maria D. Esteve-Gassent
- Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical sciences, Texas A&M University, College Station, TX-77843, USA
| | - Ivan Castro-Arellano
- Department of Biology, College of Science and Engineering, Texas State University, San Marcos, TX-78666, USA
| | - Teresa P. Feria-Arroyo
- Department of Biology, The University of Texas Rio Grande Valley, Edinburg, TX-78539, USA
| | - Ramiro Patino
- Department of Biology, The University of Texas Rio Grande Valley, Edinburg, TX-78539, USA
| | - Andrew Y. Li
- USDA-ARS Invasive Insect Biocontrol and Behavior Laboratory, Beltsville, Maryland 20705, USA
| | - Raul F. Medina
- Department of Entomology, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX-77843, USA
| | - Adalberto A. Pérez de León
- USDA-ARS Knipling-Bushland U.S. Livestock Insects Research Laboratory, and Veterinary Pest Genomics Center, Kerrville, TX-78028, USA
| | - Roger Iván Rodríguez-Vivas
- Campus de Ciencias Biológicas y Agropecuarias. Facultad de Medicina Veterinaria y Zootecnia. Km 15.5 carretera Mérida-Xmatkuil. Yucatán, México
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The Microbiome of Ehrlichia-Infected and Uninfected Lone Star Ticks (Amblyomma americanum). PLoS One 2016; 11:e0146651. [PMID: 26751816 PMCID: PMC4709196 DOI: 10.1371/journal.pone.0146651] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 12/21/2015] [Indexed: 11/19/2022] Open
Abstract
The Lone Star tick, Amblyomma americanum, transmits several bacterial pathogens including species of Anaplasma and Ehrlichia. Amblyomma americanum also hosts a number of non-pathogenic bacterial endosymbionts. Recent studies of other arthropod and insect vectors have documented that commensal microflora can influence transmission of vector-borne pathogens; however, little is known about tick microbiomes and their possible influence on tick-borne diseases. Our objective was to compare bacterial communities associated with A. americanum, comparing Anaplasma/Ehrlichia -infected and uninfected ticks. Field-collected questing specimens (n = 50) were used in the analyses, of which 17 were identified as Anaplasma/Ehrlichia infected based on PCR amplification and sequencing of groEL genes. Bacterial communities from each specimen were characterized using Illumina sequencing of 16S rRNA gene amplicon libraries. There was a broad range in diversity between samples, with inverse Simpson’s Diversity indices ranging from 1.28–89.5. There were no statistical differences in the overall microbial community structure between PCR diagnosed Anaplasma/Ehrlichia-positive and negative ticks, but there were differences based on collection method (P < 0.05), collection site (P < 0.05), and sex (P < 0.1) suggesting that environmental factors may structure A. americanum microbiomes. Interestingly, there was not always agreement between Illumina sequencing and PCR diagnostics: Ehrlichia was identified in 16S rRNA gene libraries from three PCR-negative specimens; conversely, Ehrlichia was not found in libraries of six PCR-positive ticks. Illumina sequencing also helped identify co-infections, for example, one specimen had both Ehrlichia and Anaplasma. Other taxa of interest in these specimens included Coxiella, Borrelia, and Rickettsia. Identification of bacterial community differences between specimens of a single tick species from a single geographical site indicates that intra-species differences in microbiomes were not due solely to pathogen presence/absence, but may be also driven by vector life history factors, including environment, life stage, population structure, and host choice.
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Berret J, Voordouw MJ. Lyme disease bacterium does not affect attraction to rodent odour in the tick vector. Parasit Vectors 2015; 8:249. [PMID: 25928557 PMCID: PMC4417542 DOI: 10.1186/s13071-015-0856-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 04/13/2015] [Indexed: 12/03/2022] Open
Abstract
Background Vector-borne pathogens experience a conflict of interest when the arthropod vector chooses a vertebrate host that is incompetent for pathogen transmission. The qualitative manipulation hypothesis suggests that vector-borne pathogens can resolve this conflict in their favour by manipulating the host choice behaviour of the arthropod vector. Methods European Lyme disease is a model system for studying this conflict because Ixodes ricinus is a generalist tick species that vectors Borrelia pathogens that are specialized on different classes of vertebrate hosts. Avian specialists like B. garinii cannot survive in rodent reservoir hosts and vice versa for rodent specialists like B. afzelii. The present study tested whether Borrelia genospecies influenced the attraction of field-collected I. ricinus nymphs to rodent odours. Results Nymphs were significantly attracted to questing perches that had been scented with mouse odours. However, there was no difference in questing behaviour between nymphs infected with rodent- versus bird-specialized Borrelia genospecies. Conclusion Our study suggests that the tick, and not the pathogen, controls the early stages of host choice behaviour. Electronic supplementary material The online version of this article (doi:10.1186/s13071-015-0856-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jérémy Berret
- Laboratory of Ecology and Evolution of Parasites, Institute of Biology, University of Neuchâtel, Rue Emile-Argand 11, 2000, Neuchâtel, Switzerland.
| | - Maarten Jeroen Voordouw
- Laboratory of Ecology and Evolution of Parasites, Institute of Biology, University of Neuchâtel, Rue Emile-Argand 11, 2000, Neuchâtel, Switzerland.
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Herrmann C, Gern L. Search for blood or water is influenced by Borrelia burgdorferi in Ixodes ricinus. Parasit Vectors 2015; 8:6. [PMID: 25560984 PMCID: PMC4311481 DOI: 10.1186/s13071-014-0526-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 11/05/2014] [Indexed: 11/23/2022] Open
Abstract
An increasing number of studies suggest that vector-borne parasites are able to alter phenotypic traits in their arthropod vectors so that microorganism transmission is enhanced. This review documents this phenomenon, which occurs between Borrelia burgdorferi bacteria, the causative agents of Lyme borreliosis, and their tick vectors belonging to the Ixodes ricinus complex. It also reviews the influence of other tick-borne pathogens on these ticks. Ticks belonging to the Ixodes ricinus complex benefit from Borrelia infection by an increased lifespan (more fat and more resistance to desiccation) and by an increased questing period (less need to move to the litter zone to rehydrate), which enhances tick chances to find a host and to subsequently transmit the pathogens.
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Affiliation(s)
- Coralie Herrmann
- Institute of Biology, Eco-Epidemiology Laboratory, University of Neuchâtel, Emile-Argand 11, 2000, Neuchâtel, Switzerland.
| | - Lise Gern
- Institute of Biology, Eco-Epidemiology Laboratory, University of Neuchâtel, Emile-Argand 11, 2000, Neuchâtel, Switzerland.
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Abstract
A challenge in managing vector-borne zoonotic diseases in human and wildlife populations is predicting where epidemics or epizootics are likely to occur, and this requires knowing in part the likelihood of infected insect vectors dispersing pathogens from existing infection foci to novel areas. We measured prevalence of an arbovirus, Buggy Creek virus, in dispersing and resident individuals of its exclusive vector, the ectoparasitic swallow bug (Oeciacus vicarius), that occupies cliff swallow (Petrochelidon pyrrhonota) colonies in western Nebraska. Bugs colonizing new colony sites and immigrating into established colonies by clinging to the swallows' legs and feet had significantly lower virus prevalence than bugs in established colonies and those that were clustering in established colonies before dispersing. The reduced likelihood of infected bugs dispersing to new colony sites indicates that even heavily infected sites may not always export virus to nearby foci at a high rate. Infected arthropods should not be assumed to exhibit the same dispersal or movement behaviour as uninfected individuals, and these differences in dispersal should perhaps be considered in the epidemiology of vector-borne pathogens such as arboviruses.
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Affiliation(s)
- Amy T Moore
- Department of Biological Sciences, University of Tulsa, , Tulsa, OK 74104, USA
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Heylen D, Sprong H, van Oers K, Fonville M, Leirs H, Matthysen E. Are the specialized bird ticks, Ixodes arboricola and I. frontalis, competent vectors for Borrelia burgdorferi sensu lato? Environ Microbiol 2013; 16:1081-9. [PMID: 24237635 DOI: 10.1111/1462-2920.12332] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 11/05/2013] [Indexed: 11/30/2022]
Abstract
Our study tested whether two European bird-specialized ticks, Ixodes arboricola and I. frontalis, can act as vectors in the transmission cycles of Borrelia burgdorferi s.l. The ticks have contrasting ecologies but share songbird hosts (such as the great tit, Parus major) with the generalist I. ricinus which may therefore act as a bridging vector. In the first phase of the experiment, we obtained Borrelia-infected ornithophilic nymphs by exposing larvae to great tits that had previously been exposed to I. ricinus nymphs carrying a community of genospecies (Borrelia garinii, valaisiana, afzelii, burgdorferi s.s., spielmanii). Skin samples showed that birds selectively amplified B. garinii and B. valaisiana. The spirochetes were transmitted to the ornithophilic ticks and survived moulting, leading to infection rates of 16% and 27% in nymphs of I. arboricola and I. frontalis respectively. In the second phase, pathogen-free great tits were exposed to the Borrelia-infected ornithophilic nymphs. None of these ticks were able to infect the birds, as indicated by the tissue samples. Analysis of xenodiagnostic I. ricinus larvae found no evidence for co-feeding or systemic transmission of B. burgdorferi s.l. These outcomes do not support the occurrence of enzootic cycles of Borrelia burgdorferi s.l. involving songbirds and their specialized ornithophilic ticks.
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Affiliation(s)
- Dieter Heylen
- Department of Biology, University of Antwerp, Evolutionary Ecology Group, Belgium
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Herrmann C, Voordouw MJ, Gern L. Ixodes ricinus ticks infected with the causative agent of Lyme disease, Borrelia burgdorferi sensu lato, have higher energy reserves. Int J Parasitol 2013; 43:477-83. [PMID: 23416154 DOI: 10.1016/j.ijpara.2012.12.010] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Revised: 12/19/2012] [Accepted: 12/22/2012] [Indexed: 10/27/2022]
Abstract
Ticks use their energy reserves to maintain their water balance, search for hosts and transmit tick-borne pathogens. However, the influence of tick-borne pathogens on the energy reserves of the tick vector has not been well studied. The relationship between Borrelia burgdorferi sensu lato (s.l.) infection status and fat content in questing Ixodes ricinus nymphs was examined. Nymphs were sampled from the field. Their body mass and fat content were measured, and their Borrelia genospecies infection status (using reverse line blot analysis), and spirochete load (using quantitative PCR) were analysed. Of the 900 nymphs tested, 21.2% were infected with a variety of Borrelia genospecies. Borrelia-infected nymphs had 12.1% higher fat content than uninfected ticks after correcting for body size. For the subset of Borrelia-infected nymphs, no relationship was found between spirochete load and fat content and bioenergetics calculations suggest that Borrelia spirochetes consume a negligible fraction of the tick energy reserves. While the mechanism that causes the association between Borrelia infection and higher fat content in I. ricinus nymphs remains unknown, the present study complements our previous findings that Borrelia-infected nymphs had higher survival times under desiccating conditions and walked less within a humidity gradient.
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Affiliation(s)
- C Herrmann
- Institute of Biology, Laboratory of Eco-Epidemiology of Parasites, University of Neuchâtel, Emile Argand 11, 2000 Neuchâtel, Switzerland.
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Kagemann J, Clay K. Effects of infection by Arsenophonus and Rickettsia bacteria on the locomotive ability of the ticks Amblyomma americanum, Dermacentor variabilis, and Ixodes scapularis. JOURNAL OF MEDICAL ENTOMOLOGY 2013; 50:155-162. [PMID: 23427665 DOI: 10.1603/me12086] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The goal of this study was to determine the effect of vertically transmitted Arsenophonus and Rickettsia bacteria on locomotive ability of larvae of three eastern North American tick species: Amblyomma americanum, Dermacentor variabilis, and Ixodes scapularis. We conducted two different experiments on flat or inclined surfaces to measure tick motility. In each experiment, a moderately heated surface was used and placed at a selected incline. The individual's path across the surface was traced for a period of 2 min, or until the larval tick had moved off the surface. Following the microbial identification of Arsenophonus and Rickettsia, a mixed model analysis of variance (ANOVA) indicated that clutch microbial infection status had a significant effect on tick motility with Rickettsia increasing and Arsenophonus decreasing motility averaged over tick species and inclines. There was also a significant difference in motility among tick species and a highly significant effect of the Species*Incline interaction where Dermacentor had higher motility than Ixodes on the flat surface.
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Affiliation(s)
- Jonathan Kagemann
- Department of Biology, Indiana University, 1001 East Third Street, Bloomington, IN 47405-3700, USA
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Romashchenko AV, Ratushnyak AS, Zapara TA, Tkachev SE, Moshkin MP. The correlation between tick (Ixodes persulcatus Sch.) questing behaviour and synganglion neuronal responses to odours. JOURNAL OF INSECT PHYSIOLOGY 2012; 58:903-910. [PMID: 22497860 DOI: 10.1016/j.jinsphys.2012.04.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Revised: 04/01/2012] [Accepted: 04/03/2012] [Indexed: 05/31/2023]
Abstract
We examined the behavioural and electrophysiological responses of taiga ticks (Ixodes persulcatus) to several olfactory stimuli: Osmopherone® (5-a-androst-16-en-3-ol), Osmopherine® (butanoic and 3-methylbutanoic acids), DEET® (N,N-diethyl-meta-toluamide), ethanol (96%), and water (control stimulus). To study individual tick behavioural reactions to these stimuli, we used a Y-shaped glass maze (n=50). To study the electrophysiological reactions of the ticks' synganglia to these olfactory stimuli, we recorded the shifts of total potential (TP) of pre-oesophageal neurons in response to odour stimulation of Haller's organ (n=25). We found that Osmopherine® attracted ticks and frequently evoked negative shifts of TP, whereas the response to Osmopherone® did not differ from the reaction to water. DEET® and ethanol acted as tick repellents and generally evoked positive shifts of TP. We also tested each tick for its questing height (QH) on a glass rod that was at an incline of 75°, and we tested for the presence of pathogens i.e., DNA of Borrelia burgdorferi sp. s.l. and RNA of tick-borne encephalitis virus (TBEV). The degree of response to Osmopherine® positively correlated with the QH. The ticks with the highest values of QH showed a greater prevalence of the tick-borne pathogen Borrelia sp. s.l. compared with the ticks that did not reach the maximum QH. The present results show a correlation between the electrophysiological reaction of the synganglia of ticks and their behavioural responses to different odours.
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Affiliation(s)
- A V Romashchenko
- Institute of Cytology and Genetics, SB RAN, Novosibirsk, Academic Lavrent'ev Avenue, 10, Russia.
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Estrada-Peña A, Ayllón N, de la Fuente J. Impact of climate trends on tick-borne pathogen transmission. Front Physiol 2012; 3:64. [PMID: 22470348 PMCID: PMC3313475 DOI: 10.3389/fphys.2012.00064] [Citation(s) in RCA: 147] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Accepted: 03/05/2012] [Indexed: 01/01/2023] Open
Abstract
Recent advances in climate research together with a better understanding of tick-pathogen interactions, the distribution of ticks and the diagnosis of tick-borne pathogens raise questions about the impact of environmental factors on tick abundance and spread and the prevalence and transmission of tick-borne pathogens. While undoubtedly climate plays a role in the changes in distribution and seasonal abundance of ticks, it is always difficult to disentangle factors impacting on the abundance of tick hosts from those exerted by human habits. All together, climate, host abundance, and social factors may explain the upsurge of epidemics transmitted by ticks to humans. Herein we focused on tick-borne pathogens that affect humans with epidemic potential. Borrelia burgdorferi s.l. (Lyme disease), Anaplasma phagocytophilum (human granulocytic anaplasmosis), and tick-borne encephalitis virus (tick-borne encephalitis) are transmitted by Ixodes spp. Crimean-Congo hemorrhagic fever virus (Crimean-Congo hemorrhagic fever) is transmitted by Hyalomma spp. In this review, we discussed how vector tick species occupy the habitat as a function of different climatic factors, and how these factors impact on tick survival and seasonality. How molecular events at the tick-pathogen interface impact on pathogen transmission is also discussed. Results from statistically and biologically derived models are compared to show that while statistical models are able to outline basic information about tick distributions, biologically derived models are necessary to evaluate pathogen transmission rates and understand the effect of climatic variables and host abundance patterns on pathogen transmission. The results of these studies could be used to build early alert systems able to identify the main factors driving the subtle changes in tick distribution and seasonality and the prevalence of tick-borne pathogens.
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Affiliation(s)
- Agustín Estrada-Peña
- Department of Parasitology, Veterinary Faculty, University of ZaragozaZaragoza, Spain
| | - Nieves Ayllón
- Instituto de Investigación en Recursos CinegéticosCSIC–UCLM–JCCM, Ciudad Real, Spain
| | - José de la Fuente
- Instituto de Investigación en Recursos CinegéticosCSIC–UCLM–JCCM, Ciudad Real, Spain
- Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State UniversityStillwater, OK, USA
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Busby AT, Ayllón N, Kocan KM, Blouin EF, de la Fuente G, Galindo RC, Villar M, de la Fuente J. Expression of heat shock proteins and subolesin affects stress responses, Anaplasma phagocytophilum infection and questing behaviour in the tick, Ixodes scapularis. MEDICAL AND VETERINARY ENTOMOLOGY 2012; 26:92-102. [PMID: 21781141 DOI: 10.1111/j.1365-2915.2011.00973.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We characterized the effects of subolesin and heat shock protein (HSP) expression on Ixodes scapularis Say (Acari: Ixodidae) stress responses to heat shock and feeding, questing behaviour and Anaplasma phagocytophilum (Rickettsiales: Anaplasmataceae) infection. Ticks and cultured tick cells were analysed before and after subolesin, hsp20 and hsp70 gene knock-down by RNA interference. The results of these studies confirm that HSPs are involved in the tick cell response to heat stress and that subolesin and HSPs are both involved in the tick response to blood-feeding stress and A. phagocytophilum infection. Subolesin and hsp20 are involved in the tick protective response to A. phagocytophilum infection and hsp70 expression may be manipulated by the pathogen to increase infectivity. Importantly, these results demonstrate that subolesin, hsp20 and hsp70 expression also affect tick questing behaviour. Overall, this research demonstrates a relationship between hsp and subolesin expression and tick stress responses to heat shock and blood feeding, A. phagocytophilum infection and questing behaviour, thereby extending our understanding of the tick-host-pathogen interface.
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Affiliation(s)
- A T Busby
- Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK, U.S.A
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42
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Heylen DJA, Matthysen E. Experimental evidence for host preference in a tick parasitizing songbird nestlings. OIKOS 2011. [DOI: 10.1111/j.1600-0706.2010.19358.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Radulović Ž, Milutinović M, Tomanović S, Mulenga A. Detection of Borrelia-specific 16S rRNA sequence in total RNA extracted from Ixodes ricinus ticks. ARQ BRAS MED VET ZOO 2010. [DOI: 10.1590/s0102-09352010000400015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A reverse transcriptase - polymerase chain reaction based assay for Borrelia species detection in ticks was developed. The method was based on amplification of 552 nucleotide bases long sequence of 16S rRNA, targeted by Borrelia specific primers. In the present study, total RNA extracted from Ixodes ricinus ticks was used as template. The results showed higher sensitivity for Borrelia detection as compared to standard dark-field microscopy. Method specificity was confirmed by cloning and sequencing of obtained 552 base pairs long amplicons. Phylogenetic analysis of obtained sequences showed that they belong to B. lusitaniae and B. afzelii genospecies. RT-PCR based method presented in this paper could be very useful as a screening test for detecting pathogen presence, especially when in investigations is required extraction of total RNA from ticks.
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Lane RS, Mun J, Stubbs HA. Horizontal and vertical movements of host-seeking Ixodes pacificus (Acari: Ixodidae) nymphs in a hardwood forest. JOURNAL OF VECTOR ECOLOGY : JOURNAL OF THE SOCIETY FOR VECTOR ECOLOGY 2009; 34:252-66. [PMID: 20352083 PMCID: PMC2844093 DOI: 10.1111/j.1948-7134.2009.00034.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The nymph of the western black-legged tick (Ixodes pacificus) is an important bridging vector of the Lyme disease spirochete (Borrelia burgdorferi) to humans in the far-western United States. The previously unknown dispersal capabilities of this life stage were studied in relation to logs, tree trunks, and adjacent leaf-litter areas in a mixed hardwood forest using mark-release-recapture methods. In two spatially and temporally well-spaced trials involving logs, the estimated mean distances that nymphs dispersed ranged from approximately 0.04 to 0.20 m/day on logs vs 0.11 to 0.72 m/day in litter. Prior to recapture in either trial and within the confines of the sampling grids, the greatest estimated dispersal distances by individual nymphs released on logs, and in litter 0.5 m or 1.5 m from logs, were 2.4, 3.0, and 3.0 m, respectively. Nymphs released on logs or litter tended to remain within the same biotopes in which they were freed while host-seeking. In two simultaneous trials involving trunks spaced close-at-hand, nymphs released at the trunk/litter interface on all four aspects collectively dispersed a mean of 0.353 m/day on trunks vs 0.175 m/day in litter. In either trial, the greatest distances that recaptured nymphs climbed trunks, or dispersed in litter in an encircling 3-m grid, were 1.55 m and 2.97 m, respectively. Nymphs ascending trunks did not exhibit a preference for any one aspect, and the B. burgdorferi-infection prevalences in nymphs that climbed trunks (3.2-4.0%) did not differ significantly from those that moved horizontally into litter (10.5-17.6%). We conclude that I. pacificus nymphs use an ambush host-seeking strategy; that they disperse slowly in all biotopes studied; that they usually continue to host-seek in or on whatever substratum they access initially; and that B. burgdorferi-infected nymphs are as likely to move horizontally as vertically when offered a choice.
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Affiliation(s)
- Robert S Lane
- Department of Environmental Science, Policy and Management, University of California, Berkeley, CA 94720, USA
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45
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Belliure B, Janssen A, Sabelis MW. Herbivore benefits from vectoring plant virus through reduction of period of vulnerability to predation. Oecologia 2008; 156:797-806. [PMID: 18392858 PMCID: PMC2469278 DOI: 10.1007/s00442-008-1027-9] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2007] [Revised: 03/07/2008] [Accepted: 03/07/2008] [Indexed: 11/24/2022]
Abstract
Herbivores can profit from vectoring plant pathogens because the induced defence of plants against pathogens sometimes interferes with the induced defence of plants against herbivores. Plants can also defend themselves indirectly by the action of the natural enemies of the herbivores. It is unknown whether the defence against pathogens induced in the plant also interferes with the indirect defence against herbivores mediated via the third trophic level. We previously showed that infection of plants with Tomato spotted wilt virus (TSWV) increased the developmental rate of and juvenile survival of its vector, the thrips Frankliniella occidentalis. Here, we present the results of a study on the effects of TSWV infections of plants on the effectiveness of three species of natural enemies of F. occidentalis: the predatory mites Neoseiulus cucumeris and Iphiseius degenerans, and the predatory bug Orius laevigatus. The growth rate of thrips larvae was positively affected by the presence of virus in the host plant. Because large larvae are invulnerable to predation by the two species of predatory mites, this resulted in a shorter period of vulnerability to predation for thrips that developed on plants with virus than thrips developing on uninfected plants (4.4 vs. 7.9 days, respectively). Because large thrips larvae are not invulnerable to predation by the predatory bug Orius laevigatus, infection of the plant did not affect the predation risk of thrips larvae from this predator. This is the first demonstration of a negative effect of a plant pathogen on the predation risk of its vector.
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Affiliation(s)
- Belén Belliure
- Institute for Biodiversity and Ecosystem Dynamics, Section Population Biology, University of Amsterdam, PO Box 94084, 1090 GB, Amsterdam, The Netherlands.
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46
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Troughton DR, Levin ML. Life cycles of seven ixodid tick species (Acari: Ixodidae) under standardized laboratory conditions. JOURNAL OF MEDICAL ENTOMOLOGY 2007; 44:732-740. [PMID: 17915502 DOI: 10.1093/jmedent/44.5.732] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Studies of transmission, maintenance, infectivity, virulence, and pathogenicity of tick-borne agents require the use of large numbers of live laboratory-raised ticks. Colonies of Ixodes scapularis Say, Ixodes pacificus Cooley & Kohls, Amblyomma americanum (L.), Dermacentor occidentalis Marx, Dermacentor variabilis (Say), Hemaphysalis leporispalustris (Packard), and Rhipicephalus sanguineus (Latrielle) have been maintained in our laboratory at the Centers for Disease Control and Prevention for five to 18 continuous generations. New Zealand White rabbits (Oryctolagus cuniculus) are used as hosts for all tick species and developmental stages. Between feedings, ticks are stored in environmental incubators at 22-24 degrees C and 90% RH with a day/night photoperiod of 16:8 (L:D) h. The duration of feeding, molting, preoviposition, and periods of postmolting development were recorded. Here, we describe the life cycles of these common North American tick species under standardized laboratory conditions. At 22-24 degrees C, the minimal time needed for each species to complete one life cycle was as follows: I. scapularis, 204-219 d; I. pacificus, 214-229 d; R. sanguineus, 162-177 d; H. leporispalustris, 209-224 d; D. variabilis, 176-191 d; D. occidentalis, 180-195 d; and A. americanum, 192-211 d.
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Affiliation(s)
- Danielle R Troughton
- Rickettsial Zoonoses Branch, National Center for Zoonotic, Vector-Borne, and Enteric Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA
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47
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Uspensky I, Kovalevskii YV, Korenberg EI. Physiological age of field-collected female taiga ticks, Ixodes persulcatus (Acari: Ixodidae), and their infection with Borrelia burgdorferi sensu lato. EXPERIMENTAL & APPLIED ACAROLOGY 2006; 38:201-9. [PMID: 16596353 DOI: 10.1007/s10493-006-0006-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2005] [Accepted: 01/26/2006] [Indexed: 05/08/2023]
Abstract
In some studies the prevalence of tick infection (infection rate) and the intensity of infection are negatively correlated with unfed tick age (in the broad sense of this term). However, no special research has been carried out to consider the phenomenon thoroughly. The infection indices of the female taiga ticks, Ixodes persulcatus, infected with Borrelia burgdorferi s.l. were related to tick physiological age, an index that more precisely reflects tick physiological state than the time of tick collection in the field or the duration of tick survival under laboratory conditions. A novel quantitative technique of physiological age determination based on the evaluation of the ratios between sizes of the stable (scutum) and the changing (alloscutum) structures of the tick body was used. The age was estimated in accordance with the classical age-grade scale introduced by Balashov and a more fractional scale determined by the new technique. In total, 131 female ticks were examined for their infection and physiological age, 46 of which were infected with B. burgdorferi s.l. (mean infection rate 35.1%). The minimal intensity of infection was 0.4 bacterial cells per 100 fields of view whereas the maximal infection was 172 cells. There was no difference between the prevalence of infection in ticks of different physiological age. The intensity of infection obviously differed between ticks of different age groups in the scale introduced by Balashov but did not significantly differ between ticks of different age groups according to the fractional age-grade scale. The data concerning the relationships between Borrelia burgdorferi and unfed Ixodes ticks are considered.
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Affiliation(s)
- Igor Uspensky
- Department of Biological Chemistry, A. Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel.
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48
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Radulović Z, Milutinović M, Andelković M, Vujcić Z, Tomanović S, Bozić N, Marinković D. Allozyme polymorphism of Mdh and alpha-Gpdh in Ixodes ricinus populations: comparison of borreliae-infected and uninfected ticks. EXPERIMENTAL & APPLIED ACAROLOGY 2006; 40:113-21. [PMID: 17072538 DOI: 10.1007/s10493-006-9028-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2006] [Accepted: 09/15/2006] [Indexed: 05/12/2023]
Abstract
Ixodes ricinus Linnaeus (Acari: Ixodidae) ticks are vectors of numerous infectious diseases in humans and animals. The allozyme variability of MDH and alpha-Gpdh was detected by native polyacrylamide gel electrophoresis in I. ricinus natural populations in three localities in Serbia. Four alleles of Mdh locus (MDH 1, MDH 2, MDH 3 and MDH X) and four alleles of alpha-Gpdh locus (VS, S, F and VF) were detected. Interpopulation differences in Mdh and alpha-Gpdh allele frequencies were statistically insignificant. Significant difference in alpha-Gpdh allele frequencies between males and females was recorded in the largest sample only. Differences in allele frequencies, detected between borreliae-infected and uninfected I. ricinus ticks, were close to the level of statistical significance, especially for alpha-Gpdh locus. Clear significant difference appeared in females when sexes were tested separatelly (P = 0.037). It is interesting that genotypes containing rarer alleles (MDH 1 and S) were infected in higher proportion in comparison to other genotypes. Our results point towards a possible role of Mdh and alpha-Gpdh loci in I. ricinus ticks in the determination of energy requirements for host seeking. Sex differences in alpha-Gpdh allele frequencies suggest that selective pressure, concerning efficiency of reserve materials utilisation, points to alpha-Gpdh rather than to Mdh locus.
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Affiliation(s)
- Zeljko Radulović
- Laboratory for Medical Arachnoentomology, Institute for Medical Research, University of Belgrade, Dr. Subotića 4, POB 102, 11129, Belgrade, Serbia.
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49
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De Meeûs T, Lorimier Y, Renaud F. Lyme borreliosis agents and the genetics and sex of their vector, Ixodes ricinus. Microbes Infect 2004; 6:299-304. [PMID: 15026017 DOI: 10.1016/j.micinf.2003.12.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2003] [Accepted: 12/17/2003] [Indexed: 12/01/2022]
Abstract
The tick Ixodes ricinus is responsible for the transmission and maintenance of a wide variety of pathogenic organisms in the Northern Hemisphere, among which Lyme disease represents a major threat to humans. Despite numerous studies, the epidemiology of the different bacterial species responsible for this disease remains unclear. Recent evidence for a sex-biased genetic structure of its European vector leads us to analyse the consequences of this pattern on Borrelia transmission. Here we show that male and female ticks are not equivalently infected by Borrelia burgdorferi, that Borrelia afzelii affects tick migration capabilities, especially for the most vagile sex (i.e., male) and that Lyme borreliosis agents are consequently vectorised in a much more complex way than usually thought. Such results change the epidemiological perception of Lyme borreliosis and suggest new co-evolutionary pathways between the ticks and the borrelia.
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Affiliation(s)
- Thierry De Meeûs
- Centre d'Etude sur le Polymorphisme des Micro-Organismes, UMR CNRS-IRD 9926, Equipe Evolution des Systèmes Symbiotiques, Unite Mixte de Recherches, 911 Avenue d'Agropolis, B.P. 64501, 34394 Montpellier cedex 5, France.
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50
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Vail SC, Smith G. Vertical movement and posture of blacklegged tick (Acari: Ixodidae) nymphs as a function of temperature and relative humidity in laboratory experiments. JOURNAL OF MEDICAL ENTOMOLOGY 2002; 39:842-846. [PMID: 12495181 DOI: 10.1603/0022-2585-39.6.842] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We measured three components of the behavioral activity of blacklegged tick (Ixodes scapularis Say) nymphs under controlled conditions of daylength, temperature, and relative humidity in the laboratory. Temperature and relative humidity were experimentally manipulated among replicated treatment groups in two experiments. Humidity treatment had a significant effect on mean questing height, which was greater at 100% RH than at any lower humidity (P < 0.01), but it had no effect on mean distance moved between observations or the mean percentage of time in questing posture. Temperature had no effect on mean questing height, but significantly affected mean distance moved (P < 0.01) and the percentage of time in questing posture (P < 0.001). Mean distance moved and percentage of time in questing posture were both greater at 25 degrees C than at higher or lower temperatures. A mechanistic understanding of the factors affecting tick behavior is likely to be useful for interpreting field data, designing field studies, and predicting risk of exposure to tick-borne pathogens.
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Affiliation(s)
- Stephen C Vail
- Department of Biology, William Paterson University, Wayne, NJ 07470, USA.
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