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Bakker JW, Esser HJ, Sprong H, Godeke GJ, Hoornweg TE, de Boer WF, Pijlman GP, Koenraadt CJM. Differential susceptibility of geographically distinct Ixodes ricinus populations to tick-borne encephalitis virus and louping ill virus. Emerg Microbes Infect 2024; 13:2321992. [PMID: 38484290 PMCID: PMC10946273 DOI: 10.1080/22221751.2024.2321992] [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: 03/19/2024]
Abstract
Tick-borne encephalitis virus (TBEV) is an emerging pathogen in the Netherlands. Multiple divergent viral strains are circulating and the focal distribution of TBEV remains poorly understood. This may, however, be explained by differences in the susceptibility of tick populations for specific viruses and viral strains, and by viral strains having higher infection success in their local tick population. We investigated this hypothesis by exposing Dutch Ixodes ricinus ticks to two different TBEV strains: TBEV-NL from the Netherlands and TBEV-Neudoerfl from Austria. In addition, we exposed ticks to louping Ill virus (LIV), which is endemic to large parts of the United Kingdom and Ireland, but has not been reported in the Netherlands. Ticks were collected from two locations in the Netherlands: one location without evidence of TBEV circulation and one location endemic for the TBEV-NL strain. Ticks were infected in a biosafety level 3 laboratory using an artificial membrane feeding system. Ticks collected from the region without evidence of TBEV circulation had lower infection rates for TBEV-NL as compared to TBEV-Neudoerfl. Vice versa, ticks collected from the TBEV-NL endemic region had higher infection rates for TBEV-NL compared to TBEV-Neudoerfl. In addition, LIV infection rates were much lower in Dutch ticks compared to TBEV, which may explain why LIV is not present in the Netherlands. Our findings show that ticks from two distinct geographical populations differ in their susceptibility to TBEV strains, which could be the result of differences in the genetic background of the tick populations.
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Affiliation(s)
- Julian W. Bakker
- Laboratory of Entomology, Wageningen University & Research, Wageningen, Netherlands
| | - Helen J. Esser
- Wildlife Ecology and Conservation Group, Wageningen University & Research, Wageningen, Netherlands
| | - Hein Sprong
- Centre for Infectious Disease Control, National Institute of Public Health and the Environment (RIVM), Bilthoven, Netherlands
| | - Gert-Jan Godeke
- Centre for Infectious Disease Control, National Institute of Public Health and the Environment (RIVM), Bilthoven, Netherlands
| | - Tabitha E. Hoornweg
- Centre for Infectious Disease Control, National Institute of Public Health and the Environment (RIVM), Bilthoven, Netherlands
| | - Willem F. de Boer
- Wildlife Ecology and Conservation Group, Wageningen University & Research, Wageningen, Netherlands
| | - Gorben P. Pijlman
- Laboratory of Virology, Wageningen University & Research, Wageningen, Netherlands
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Mansfield KL, Schilling M, Sanders C, Holding M, Johnson N. Arthropod-Borne Viruses of Human and Animal Importance: Overwintering in Temperate Regions of Europe during an Era of Climate Change. Microorganisms 2024; 12:1307. [PMID: 39065076 PMCID: PMC11278640 DOI: 10.3390/microorganisms12071307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2024] [Revised: 06/20/2024] [Accepted: 06/22/2024] [Indexed: 07/28/2024] Open
Abstract
The past three decades have seen an increasing number of emerging arthropod-borne viruses in temperate regions This process is ongoing, driven by human activities such as inter-continental travel, combined with the parallel emergence of invasive arthropods and an underlying change in climate that can increase the risk of virus transmission and persistence. In addition, natural events such as bird migration can introduce viruses to new regions. Despite the apparent regularity of virus emergence, arthropod-borne viruses circulating in temperate regions face the challenge of the late autumn and winter months where the arthropod vector is inactive. Viruses therefore need mechanisms to overwinter or they will fail to establish in temperate zones. Prolonged survival of arthropod-borne viruses within the environment, outside of both vertebrate host and arthropod vector, is not thought to occur and therefore is unlikely to contribute to overwintering in temperate zones. One potential mechanism is continued infection of a vertebrate host. However, infection is generally acute, with the host either dying or producing an effective immune response that rapidly clears the virus. There are few exceptions to this, although prolonged infection associated with orbiviruses such as bluetongue virus occurs in certain mammals, and viraemic vertebrate hosts therefore can, in certain circumstances, provide a route for long-term viral persistence in the absence of active vectors. Alternatively, a virus can persist in the arthropod vector as a mechanism for overwintering. However, this is entirely dependent on the ecology of the vector itself and can be influenced by changes in the climate during the winter months. This review considers the mechanisms for virus overwintering in several key arthropod vectors in temperate areas. We also consider how this will be influenced in a warming climate.
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Affiliation(s)
- Karen L. Mansfield
- Vector Borne Diseases, Virology Department, Animal and Plant Health Agency, Woodham Lane, Addlestone, Surrey KT15 3NB, UK; (K.L.M.); (M.S.)
| | - Mirjam Schilling
- Vector Borne Diseases, Virology Department, Animal and Plant Health Agency, Woodham Lane, Addlestone, Surrey KT15 3NB, UK; (K.L.M.); (M.S.)
| | | | - Maya Holding
- Virology and Pathogenesis Group, UK Health Security Agency, Porton Down, Salisbury SP4 0JG, UK;
| | - Nicholas Johnson
- Vector Borne Diseases, Virology Department, Animal and Plant Health Agency, Woodham Lane, Addlestone, Surrey KT15 3NB, UK; (K.L.M.); (M.S.)
- Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XH, UK
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Hills SL, Poehling KA, Chen WH, Staples JE. Tick-Borne Encephalitis Vaccine: Recommendations of the Advisory Committee on Immunization Practices, United States, 2023. MMWR Recomm Rep 2023; 72:1-29. [PMID: 37943707 PMCID: PMC10651317 DOI: 10.15585/mmwr.rr7205a1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2023] Open
Abstract
Tick-borne encephalitis (TBE) virus is focally endemic in parts of Europe and Asia. The virus is primarily transmitted to humans by the bites of infected Ixodes species ticks but can also be acquired less frequently by alimentary transmission. Other rare modes of transmission include through breastfeeding, blood transfusion, solid organ transplantation, and slaughtering of viremic animals. TBE virus can cause acute neurologic disease, which usually results in hospitalization, often permanent neurologic or cognitive sequelae, and sometimes death. TBE virus infection is a risk for certain travelers and for laboratory workers who work with the virus. In August 2021, the Food and Drug Administration approved Ticovac TBE vaccine for use among persons aged ≥1 year. This report summarizes the epidemiology of and risks for infection with TBE virus, provides information on the immunogenicity and safety of TBE vaccine, and summarizes the recommendations of the Advisory Committee on Immunization Practices (ACIP) for use of TBE vaccine among U.S. travelers and laboratory workers. The risk for TBE for most U.S. travelers to areas where the disease is endemic is very low. The risk for exposure to infected ticks is highest for persons who are in areas where TBE is endemic during the main TBE virus transmission season of April–November and who are planning to engage in recreational activities in woodland habitats or who might be occupationally exposed. All persons who travel to areas where TBE is endemic should be advised to take precautions to avoid tick bites and to avoid the consumption of unpasteurized dairy products because alimentary transmission of TBE virus can occur. TBE vaccine can further reduce infection risk and might be indicated for certain persons who are at higher risk for TBE. The key factors in the risk-benefit assessment for vaccination are likelihood of exposure to ticks based on activities and itinerary (e.g., location, rurality, season, and duration of travel or residence). Other risk-benefit considerations should include 1) the rare occurrence of TBE but its potentially high morbidity and mortality, 2) the higher risk for severe disease among certain persons (e.g., older persons aged ≥60 years), 3) the availability of an effective vaccine, 4) the possibility but low probability of serious adverse events after vaccination, 5) the likelihood of future travel to areas where TBE is endemic, and 6) personal perception and tolerance of risk ACIP recommends TBE vaccine for U.S. persons who are moving or traveling to an area where the disease is endemic and will have extensive exposure to ticks based on their planned outdoor activities and itinerary. Extensive exposure can be considered based on the duration of travel and frequency of exposure and might include shorter-term (e.g., <1 month) travelers with daily or frequent exposure or longer-term travelers with regular (e.g., a few times a month) exposure to environments that might harbor infected ticks. In addition, TBE vaccine may be considered for persons who might engage in outdoor activities in areas where ticks are likely to be found, with a decision to vaccinate made on the basis of an assessment of their planned activities and itinerary, risk factors for a poor medical outcome, and personal perception and tolerance of risk. In the laboratory setting, ACIP recommends TBE vaccine for laboratory workers with a potential for exposure to TBE virus
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Potential Mammalian Vector-Borne Diseases in Live and Wet Markets in Indonesia and Myanmar. MICROBIOLOGY RESEARCH 2023. [DOI: 10.3390/microbiolres14010011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Vector-borne diseases spread from wild animals and their associated ectoparasites to humans and domesticated animals. Wildlife markets are recognized as important areas where this transfer can take place. We assessed the potential for spreading vector-borne diseases in two live and wet markets in Myanmar (Mong La, on the Myanmar-China border) and Indonesia (Sukahaji in Bandung on the island of Java) by making an inventory of all live and freshly killed wild mammals for sale. For eight mammal families, we quantified the number of animals on offer, and we used a heatmap cluster analysis to map vector-borne diseases that these families may carry. In Myanmar, we observed large numbers of wild pigs and deer (potentially carrying West Nile and various encephalitis viruses) whereas in Indonesia we observed Old World fruit bats (potentially carrying Chikungunya and encephalitis viruses) and squirrels (potentially carrying West Nile and encephalitis viruses). The trade in Indonesia was dominated by live mammals offered for sale as pets, and only Old World fruit bats and squirrels traded for traditional Asian medicine were killed in the markets. The trade in Myanmar was more geared towards wild meat (e.g., wild pigs, deer, primates) and traditional Asian medicine (squirrels). The combined risks of vector-borne diseases spreading from traded animals to human health highlight the need for an integrated approach protecting public health, economic interests and biodiversity.
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Belova OA, Polienko AE, Averianova AD, Karganova GG. Hybrids of Ixodes ricinus and Ixodes persulcatus ticks effectively acquire and transmit tick-borne encephalitis virus. Front Cell Infect Microbiol 2023; 13:1104484. [PMID: 36743302 PMCID: PMC9895388 DOI: 10.3389/fcimb.2023.1104484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 01/02/2023] [Indexed: 01/21/2023] Open
Abstract
Ixodes rici nus and Ixodes persulcatus ticks are the main vectors of tick-borne encephalitis virus (TBEV), which has three main subtypes connected with certain tick species: the European subtype, associated with I. ricinus, and the Siberian and Far-Eastern subtypes, associated with I. persulcatus. Distribution ranges of these species overlap and form large sympatric areas in the East European Plain and Baltic countries. It has previously been shown that crossing of I. ricinus and I. persulcatus is possible, with the appearance of sterile hybrids. Hybridization of ticks can affect not only the spread of ticks but also the properties of natural foci of arbovirus infections, in particular TBEV. In the present study, we analyzed the effectiveness of virus transmission from infected mice to larvae and nymphs and trans-stadial transmission (from larvae to nymph and adult) in I. ricinus, I. persulcatus, and hybrids. For this purpose, we bred a hybrid generation from the crossing of I. persulcatus females and I. ricinus males, and we used the Siberian and European subtypes of TBEV. We showed that after feeding on infected mice, virus prevalence in engorged ticks decreased over time, and after molting, the opposite was true. In hybrids we observed the highest acquisition effectiveness and RNA copy numbers during Siberian TBEV subtype transmission. The efficiency of trans-stadial transmission of both TBEV subtypes was similar in hybrids and parental species. After the second trans-stadial TBEV transmission, a significant increase in ticks' infection rates was observed only in specific subtype-tick combination. Our data demonstrate the possible features of TBEV circulation in the I. ricinus and I. persulcatus sympatry area.
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Affiliation(s)
- Oxana A. Belova
- Laboratory of Biology of arboviruses, Federal State Autonomous Scientific Institution "Chumakov Federal Scientific Center for Research and Development of Immune-and- Biological Products of Russian Academy of Sciences" (Institute of Poliomyelitis), Moscow, Russia,*Correspondence: Oxana A. Belova,
| | - Alexandra E. Polienko
- Laboratory of Biology of arboviruses, Federal State Autonomous Scientific Institution "Chumakov Federal Scientific Center for Research and Development of Immune-and- Biological Products of Russian Academy of Sciences" (Institute of Poliomyelitis), Moscow, Russia
| | - Anastasia D. Averianova
- Laboratory of Biology of arboviruses, Federal State Autonomous Scientific Institution "Chumakov Federal Scientific Center for Research and Development of Immune-and- Biological Products of Russian Academy of Sciences" (Institute of Poliomyelitis), Moscow, Russia
| | - Galina G. Karganova
- Laboratory of Biology of arboviruses, Federal State Autonomous Scientific Institution "Chumakov Federal Scientific Center for Research and Development of Immune-and- Biological Products of Russian Academy of Sciences" (Institute of Poliomyelitis), Moscow, Russia,Department of Virology, Biological Faculty, Lomonosov Moscow State University, Moscow, Russia
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Fitness of mCherry Reporter Tick-Borne Encephalitis Virus in Tick Experimental Models. Viruses 2022; 14:v14122673. [PMID: 36560677 PMCID: PMC9781894 DOI: 10.3390/v14122673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 11/20/2022] [Accepted: 11/25/2022] [Indexed: 12/05/2022] Open
Abstract
The tick-borne encephalitis virus (TBEV) causes a most important viral life-threatening illness transmitted by ticks. The interactions between the virus and ticks are largely unexplored, indicating a lack of experimental tools and systematic studies. One such tool is recombinant reporter TBEV, offering antibody-free visualization to facilitate studies of transmission and interactions between a tick vector and a virus. In this paper, we utilized a recently developed recombinant TBEV expressing the reporter gene mCherry to study its fitness in various tick-derived in vitro cell cultures and live unfed nymphal Ixodes ricinus ticks. The reporter virus was successfully replicated in tick cell lines and live ticks as confirmed by the plaque assay and the mCherry-specific polymerase chain reaction (PCR). Although a strong mCherry signal determined by fluorescence microscopy was detected in several tick cell lines, the fluorescence of the reporter was not observed in the live ticks, corroborated also by immunoblotting. Our data indicate that the mCherry reporter TBEV might be an excellent tool for studying TBEV-tick interactions using a tick in vitro model. However, physiological attributes of a live tick, likely contributing to the inactivity of the reporter, warrant further development of reporter-tagged viruses to study TBEV in ticks in vivo.
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Da Rold G, Obber F, Monne I, Milani A, Ravagnan S, Toniolo F, Sgubin S, Zamperin G, Foiani G, Vascellari M, Drzewniokova P, Castellan M, De Benedictis P, Citterio CV. Clinical Tick-Borne Encephalitis in a Roe Deer (Capreolus capreolus L.). Viruses 2022; 14:v14020300. [PMID: 35215891 PMCID: PMC8875940 DOI: 10.3390/v14020300] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 01/26/2022] [Accepted: 01/28/2022] [Indexed: 11/16/2022] Open
Abstract
Tick-borne encephalitis virus (TBEV) is the causative agent of tick-borne encephalitis (TBE), a severe zoonosis occurring in the Palearctic region mainly transmitted through Ixodes ticks. In Italy, TBEV is restricted to the north-eastern part of the country. This report describes for the first time a case of clinical TBE in a roe deer (Capreolus capreolus L.). The case occurred in the Belluno province, Veneto region, an area endemic for TBEV. The affected roe deer showed ataxia, staggering movements, muscle tremors, wide-base stance of the front limbs, repetitive movements of the head, persistent teeth grinding, hypersalivation and prolonged recumbency. An autopsy revealed no significant lesions to explain the neurological signs. TBEV RNA was detected in the brain by real-time RT-PCR, and the nearly complete viral genome (10,897 nucleotides) was sequenced. Phylogenetic analysis of the gene encoding the envelope protein revealed a close relationship to TBEV of the European subtype, and 100% similarity with a partial sequence (520 nucleotides) of a TBEV found in ticks in the bordering Trento province. The histological examination of the midbrain revealed lymphohistiocytic encephalitis, satellitosis and microgliosis, consistent with a viral etiology. Other viral etiologies were ruled out by metagenomic analysis of the brain. This report underlines, for the first time, the occurrence of clinical encephalitic manifestations due to TBEV in a roe deer, suggesting that this pathogen should be included in the frame of differential diagnoses in roe deer with neurologic disease.
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Affiliation(s)
- Graziana Da Rold
- U.O. Ecopathology SCT2-Belluno, Istituto Zoprofilattico Sperimentale delle Venezie (IZSVe), Via Cappellari 44/A, 32100 Belluno, Italy; (F.O.); (C.V.C.)
- OIE Collaborating Centre for Diseases at the Animal/Human Interface, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 Legnaro, Italy; (I.M.); (A.M.); (S.R.); (F.T.); (S.S.); (G.Z.); (G.F.); (M.V.); (P.D.); (M.C.); (P.D.B.)
- Correspondence:
| | - Federica Obber
- U.O. Ecopathology SCT2-Belluno, Istituto Zoprofilattico Sperimentale delle Venezie (IZSVe), Via Cappellari 44/A, 32100 Belluno, Italy; (F.O.); (C.V.C.)
- OIE Collaborating Centre for Diseases at the Animal/Human Interface, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 Legnaro, Italy; (I.M.); (A.M.); (S.R.); (F.T.); (S.S.); (G.Z.); (G.F.); (M.V.); (P.D.); (M.C.); (P.D.B.)
| | - Isabella Monne
- OIE Collaborating Centre for Diseases at the Animal/Human Interface, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 Legnaro, Italy; (I.M.); (A.M.); (S.R.); (F.T.); (S.S.); (G.Z.); (G.F.); (M.V.); (P.D.); (M.C.); (P.D.B.)
- Laboratory for Viral Genomics and Trascriptomics, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 Legnaro, Italy
| | - Adelaide Milani
- OIE Collaborating Centre for Diseases at the Animal/Human Interface, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 Legnaro, Italy; (I.M.); (A.M.); (S.R.); (F.T.); (S.S.); (G.Z.); (G.F.); (M.V.); (P.D.); (M.C.); (P.D.B.)
- Laboratory for Viral Genomics and Trascriptomics, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 Legnaro, Italy
| | - Silvia Ravagnan
- OIE Collaborating Centre for Diseases at the Animal/Human Interface, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 Legnaro, Italy; (I.M.); (A.M.); (S.R.); (F.T.); (S.S.); (G.Z.); (G.F.); (M.V.); (P.D.); (M.C.); (P.D.B.)
- Laboratory of Parasitology Micology and Sanitary Enthomology, Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell’Università 10, 35020 Legnaro, Italy
| | - Federica Toniolo
- OIE Collaborating Centre for Diseases at the Animal/Human Interface, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 Legnaro, Italy; (I.M.); (A.M.); (S.R.); (F.T.); (S.S.); (G.Z.); (G.F.); (M.V.); (P.D.); (M.C.); (P.D.B.)
- Laboratory of Parasitology Micology and Sanitary Enthomology, Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell’Università 10, 35020 Legnaro, Italy
| | - Sofia Sgubin
- OIE Collaborating Centre for Diseases at the Animal/Human Interface, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 Legnaro, Italy; (I.M.); (A.M.); (S.R.); (F.T.); (S.S.); (G.Z.); (G.F.); (M.V.); (P.D.); (M.C.); (P.D.B.)
- Laboratory of Parasitology Micology and Sanitary Enthomology, Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell’Università 10, 35020 Legnaro, Italy
| | - Gianpiero Zamperin
- OIE Collaborating Centre for Diseases at the Animal/Human Interface, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 Legnaro, Italy; (I.M.); (A.M.); (S.R.); (F.T.); (S.S.); (G.Z.); (G.F.); (M.V.); (P.D.); (M.C.); (P.D.B.)
- Laboratory for Viral Genomics and Trascriptomics, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 Legnaro, Italy
| | - Greta Foiani
- OIE Collaborating Centre for Diseases at the Animal/Human Interface, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 Legnaro, Italy; (I.M.); (A.M.); (S.R.); (F.T.); (S.S.); (G.Z.); (G.F.); (M.V.); (P.D.); (M.C.); (P.D.B.)
- Histopathology Laboratory, Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell’Universita 10, 35020 Legnaro, Italy
| | - Marta Vascellari
- OIE Collaborating Centre for Diseases at the Animal/Human Interface, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 Legnaro, Italy; (I.M.); (A.M.); (S.R.); (F.T.); (S.S.); (G.Z.); (G.F.); (M.V.); (P.D.); (M.C.); (P.D.B.)
- Histopathology Laboratory, Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell’Universita 10, 35020 Legnaro, Italy
| | - Petra Drzewniokova
- OIE Collaborating Centre for Diseases at the Animal/Human Interface, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 Legnaro, Italy; (I.M.); (A.M.); (S.R.); (F.T.); (S.S.); (G.Z.); (G.F.); (M.V.); (P.D.); (M.C.); (P.D.B.)
- Laboratory for Viral Emerging Zoonoses, Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell’Università 10, 35020 Legnaro, Italy
| | - Martina Castellan
- OIE Collaborating Centre for Diseases at the Animal/Human Interface, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 Legnaro, Italy; (I.M.); (A.M.); (S.R.); (F.T.); (S.S.); (G.Z.); (G.F.); (M.V.); (P.D.); (M.C.); (P.D.B.)
- Laboratory for Viral Emerging Zoonoses, Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell’Università 10, 35020 Legnaro, Italy
| | - Paola De Benedictis
- OIE Collaborating Centre for Diseases at the Animal/Human Interface, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 Legnaro, Italy; (I.M.); (A.M.); (S.R.); (F.T.); (S.S.); (G.Z.); (G.F.); (M.V.); (P.D.); (M.C.); (P.D.B.)
- Laboratory for Viral Emerging Zoonoses, Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell’Università 10, 35020 Legnaro, Italy
| | - Carlo Vittorio Citterio
- U.O. Ecopathology SCT2-Belluno, Istituto Zoprofilattico Sperimentale delle Venezie (IZSVe), Via Cappellari 44/A, 32100 Belluno, Italy; (F.O.); (C.V.C.)
- OIE Collaborating Centre for Diseases at the Animal/Human Interface, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 Legnaro, Italy; (I.M.); (A.M.); (S.R.); (F.T.); (S.S.); (G.Z.); (G.F.); (M.V.); (P.D.); (M.C.); (P.D.B.)
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Evaluation of two artificial infection methods of live ticks as tools for studying interactions between tick-borne viruses and their tick vectors. Sci Rep 2022; 12:491. [PMID: 35017574 PMCID: PMC8752753 DOI: 10.1038/s41598-021-04498-9] [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: 08/30/2021] [Accepted: 12/08/2021] [Indexed: 12/30/2022] Open
Abstract
Up to 170 tick-borne viruses (TBVs) have been identified to date. However, there is a paucity of information regarding TBVs and their interaction with respective vectors, limiting the development of new effective and urgently needed control methods. To overcome this gap of knowledge, it is essential to reproduce transmission cycles under controlled laboratory conditions. In this study we assessed an artificial feeding system (AFS) and an immersion technique (IT) to infect Ixodes ricinus ticks with tick-borne encephalitis (TBE) and Kemerovo (KEM) virus, both known to be transmitted predominantly by ixodid ticks. Both methods permitted TBEV acquisition by ticks and we further confirmed virus trans-stadial transmission and onward transmission to a vertebrate host. However, only artificial feeding system allowed to demonstrate both acquisition by ticks and trans-stadial transmission for KEMV. Yet we did not observe transmission of KEMV to mice (IFNAR-/- or BALB/c). Artificial infection methods of ticks are important tools to study tick-virus interactions. When optimally used under laboratory settings, they provide important insights into tick-borne virus transmission cycles.
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Salivary gland extract from the deer tick, Ixodes scapularis, facilitates neuroinvasion by Powassan virus in BALB/c mice. Sci Rep 2021; 11:20873. [PMID: 34686683 PMCID: PMC8536725 DOI: 10.1038/s41598-021-00021-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 09/28/2021] [Indexed: 12/30/2022] Open
Abstract
Powassan virus (POWV) is a neuroinvasive flavivirus transmitted to mammals by the bite of ixodid ticks. In this study, we sought to investigate the impact of tick salivary gland extract (SGE) on POWV neuroinvasion. BALB/c mice were footpad inoculated with either a high dose or a low dose of POWV, with and without Ixodes scapularis salivary gland extract. Brain and spinal cord were extracted daily, and immunohistochemical techniques were used for temporal tracking of POWV antigen. The temporal pattern of POWV staining showed a caudal to rostral spread of POWV in the brains of mice from both high dose infection groups. For the high dose infection groups, the presence of tick SGE did not influence the spread of POWV in the brain. Mice infected with the low dose of virus alone did not present POWV staining in the brain; however, in the presence of SGE, low dose infected mice presented scattered foci of POWV-infected cells throughout the brain. This study shows that tick SGE facilitates POWV neuroinvasion when mice are infected with the lower dose of POWV. We also found two patterns of central nervous system invasion that were directly influenced by the dose of POWV administered.
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Ticks and their epidemiological role in Slovakia: from the past till present. Biologia (Bratisl) 2021; 77:1575-1610. [PMID: 34548672 PMCID: PMC8446484 DOI: 10.1007/s11756-021-00845-3] [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: 04/26/2021] [Accepted: 07/06/2021] [Indexed: 01/26/2023]
Abstract
In Slovakia, 22 tick species have been found to occur to date. Among them, Ixodes ricinus, Dermacentor reticulatus, D. marginatus and marginally Haemaphysalis concinna, H. inermis and H. punctata have been identified as the species of public health relevance. Ticks in Slovakia were found to harbour and transmit zoonotic and/or potentially zoonotic agents such as tick-borne encephalitis virus (TBEV), spirochaetes of the Borrelia burgdorferi sensu lato (s.l.) complex, the relapsing fever sprirochaete Borrelia miyamotoi, bacteria belonging to the orders Rickettsiales (Rickettsia spp., Anaplasma phagocytophilum, Neoehrlichia mikurensis), Legionellales (Coxiella burnetii), and Thiotrichales (Francisella tularensis), and Babesia spp. parasites (order Piroplasmida). Ixodes ricinus is the principal vector of the largest variety of microorganisms including viruses, bacteria and piroplasms. TBEV, B. burgdorferi s.l., rickettsiae of the spotted fever group, C. burnetii and F. tularensis have been found to cause serious diseases in humans, whereas B. miyamotoi, A. phagocytophilum, N. mikurensis, Babesia microti, and B. venatorum pose lower or potential risk to humans. Distribution of TBEV has a focal character. During the last few decades, new tick-borne encephalitis (TBE) foci and their spread to new areas have been registered and TBE incidence rates have increased. Moreover, Slovakia reports the highest rates of alimentary TBE infections among the European countries. Lyme borreliosis (LB) spirochaetes are spread throughout the distribution range of I. ricinus. Incidence rates of LB have shown a slightly increasing trend since 2010. Only a few sporadic cases of human rickettsiosis, anaplasmosis and babesiosis have been confirmed thus far in Slovakia. The latest large outbreaks of Q fever and tularaemia were recorded in 1993 and 1967, respectively. Since then, a few human cases of Q fever have been reported almost each year. Changes in the epidemiological characteristics and clinical forms of tularaemia have been observed during the last few decades. Global changes and development of modern molecular tools led to the discovery and identification of emerging or new tick-borne microorganisms and symbionts with unknown zoonotic potential. In this review, we provide a historical overview of research on ticks and tick-borne pathogens in Slovakia with the most important milestones and recent findings, and outline future directions in the investigation of ticks as ectoparasites and vectors of zoonotic agents and in the study of tick-borne diseases.
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11
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Prevalence of tick-borne encephalitis virus in questing Dermacentor reticulatus and Ixodes ricinus ticks in Lithuania. Ticks Tick Borne Dis 2020; 12:101594. [PMID: 33120252 DOI: 10.1016/j.ttbdis.2020.101594] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 10/01/2020] [Accepted: 10/05/2020] [Indexed: 12/19/2022]
Abstract
The Baltic States are the region in Europe where tick-borne encephalitis (TBE) is most endemic, with one-third of the European TBE cases detected in Lithuania, Latvia and Estonia. With the Czech Republic and Germany, Lithuania has among the highest population incidences of TBE. Ticks from the Ixodidae family are the main vectors of the TBE virus (TBEV) in Europe. However, there is still a lack of data on the prevalence of TBEV in ticks in different parts of Lithuania. This study analysed the current prevalence of TBEV in the two most common tick species distributed in Lithuania: Ixodes ricinus and Dermacentor reticulatus. Questing I. ricinus (n = 7170) and D. reticulatus (n = 1676) ticks were collected from 81 locations in all ten counties of Lithuania between 2017 and 2019. The presence of TBEV was analysed using a real-time reverse transcription polymerase chain reaction (RT-PCR) and TBEV prevalence in ticks was calculated as the minimum infection rate (MIR). TBEV was detected in the three developmental stages (adults, nymphs and larvae) of I. ricinus and in D. reticulatus adults. The MIR of TBEV in the total sample of I. ricinus was 0.4 % (28/7170) and for D. reticulatus was also estimated to be 0.4 % (6/1676). TBEV-infected ticks were found in 16 locations in seven counties, with MIR ranging from 0.1 % to 1.0 %. The TBEV strains detected belong to the European subtype. To the best of the authors' knowledge, this is the first report on the prevalence of TBEV in unfed D. reticulatus ticks and in I. ricinus unfed larvae in Lithuania.
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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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13
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Feder HM, Telford S, Goethert HK, Wormser GP. Powassan Virus Encephalitis Following Brief Attachment of Connecticut Deer Ticks. Clin Infect Dis 2020; 73:e2350-e2354. [PMID: 33111953 DOI: 10.1093/cid/ciaa1183] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 08/10/2020] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Powassan virus (POWV) is a tick-transmitted pathogen that may cause severe encephalitis; experimentally, it can be transmitted within just 15 minutes following a tick bite. The deer tick virus subtype of POWV (DTV) is transmitted by the deer tick and is the likely cause of the increase in the number of POWV cases reported in the United States. However, DTV has only been definitively documented in 6 patients by molecular analysis of the virus. METHODS Two patients from Connecticut with encephalitis, who had a recent deer tick bite, were evaluated by the relevant serologic tests to determine if they had been infected with POWV. Evaluation also included molecular testing of an adult deer tick that had been removed from one of the patients. RESULTS We documented neuroinvasive POWV infection in 2 children from Connecticut. Based on the results of testing the tick removed from case 2, this patient was infected by DTV, representing the 7th reported case and the first documented case of DTV infection in a child. Of note, the duration of the tick bites in both cases was very short. CONCLUSIONS We provide the first clinical and epidemiologic evidence that POWV/DTV can be rapidly transmitted to a human host, that is, within hours of tick attachment, which is distinctive when compared to other deer tick-transmitted infections such as Lyme disease.
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Affiliation(s)
- Henry M Feder
- University of Connecticut Medical Center and Connecticut Children's Medical Center, Farmington and Hartford, Connecticut, USA
| | - Sam Telford
- Tufts University, North Grafton, Massachusetts, USA
| | | | - Gary P Wormser
- Division of Infectious Diseases, New York Medical College, Valhalla, New York, USA
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14
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Ličková M, Fumačová Havlíková S, Sláviková M, Slovák M, Drexler JF, Klempa B. Dermacentor reticulatus is a vector of tick-borne encephalitis virus. Ticks Tick Borne Dis 2020; 11:101414. [DOI: 10.1016/j.ttbdis.2020.101414] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 02/11/2020] [Accepted: 03/08/2020] [Indexed: 12/30/2022]
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15
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Management Options for Ixodes ricinus-Associated Pathogens: A Review of Prevention Strategies. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17061830. [PMID: 32178257 PMCID: PMC7143654 DOI: 10.3390/ijerph17061830] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 03/03/2020] [Accepted: 03/05/2020] [Indexed: 12/16/2022]
Abstract
Ticks are important human and animal parasites and vectors of many infectious disease agents. Control of tick activity is an effective tool to reduce the risk of contracting tick-transmitted diseases. The castor bean tick (Ixodes ricinus) is the most common tick species in Europe. It is also a vector of the causative agents of Lyme borreliosis and tick-borne encephalitis, which are two of the most important arthropod-borne diseases in Europe. In recent years, increases in tick activity and incidence of tick-borne diseases have been observed in many European countries. These increases are linked to many ecological and anthropogenic factors such as landscape management, climate change, animal migration, and increased popularity of outdoor activities or changes in land usage. Tick activity is driven by many biotic and abiotic factors, some of which can be effectively managed to decrease risk of tick bites. In the USA, recommendations for landscape management, tick host control, and tick chemical control are well-defined for the applied purpose of reducing tick presence on private property. In Europe, where fewer studies have assessed tick management strategies, the similarity in ecological factors influencing vector presence suggests that approaches that work in USA may also be applicable. In this article we review key factors driving the tick exposure risk in Europe to select those most conducive to management for decreased tick-associated risk.
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16
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Hart CE, Ribeiro JM, Kazimirova M, Thangamani S. Tick-Borne Encephalitis Virus Infection Alters the Sialome of Ixodes ricinus Ticks During the Earliest Stages of Feeding. Front Cell Infect Microbiol 2020; 10:41. [PMID: 32133301 PMCID: PMC7041427 DOI: 10.3389/fcimb.2020.00041] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 01/21/2020] [Indexed: 01/14/2023] Open
Abstract
Ticks are hematophagous arthropods that transmit a number of pathogens while feeding. Among these is tick-borne encephalitis virus (TBEV), a flavivirus transmitted by Ixodes ricinus ticks in the temperate zone of Europe. The infection results in febrile illness progressing to encephalitis and meningitis with a possibility of fatality or long-term neurological sequelae. The composition of tick saliva plays an essential role in the initial virus transmission during tick feeding. Ticks secrete a diverse range of salivary proteins to modulate the host response, such as lipocalins to control the itch and inflammatory response, and both proteases and protease inhibitors to prevent blood coagulation. Here, the effect of viral infection of adult females of Ixodes ricinus was studied with the goal of determining how the virus alters the tick sialome to modulate host tissue response at the site of infection. Uninfected ticks or those infected with TBEV were fed on mice and removed and dissected one- and 3-h post-attachment. RNA from the salivary glands of these ticks, as well as from unfed ticks, was extracted and subjected to next-generation sequencing to determine the expression of key secreted proteins at each timepoint. Genes showing statistically significant up- or down-regulation between infected and control ticks were selected and compared to published literature to ascertain their function. From this, the effect of tick viral infection on the modulation of the tick-host interface was determined. Infected ticks were found to differentially express a number of uncategorized genes, proteases, Kunitz-type serine protease inhibitors, cytotoxins, and lipocalins at different timepoints. These virus-induced changes to the tick sialome may play a significant role in facilitating virus transmission during the early stages of tick feeding.
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Affiliation(s)
- Charles E. Hart
- SUNY Center for Environmental Health and Medicine, SUNY Upstate Medical University, Syracuse, NY, United States
- Institute for Global Health and Translational Science, SUNY Upstate Medical University, Syracuse, NY, United States
- The Institute for Translational Science, University of Texas Medical Branch, Galveston, TX, United States
| | - Jose M. Ribeiro
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, Bethesda, MD, United States
| | - Maria Kazimirova
- Institute of Zoology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Saravanan Thangamani
- SUNY Center for Environmental Health and Medicine, SUNY Upstate Medical University, Syracuse, NY, United States
- Institute for Global Health and Translational Science, SUNY Upstate Medical University, Syracuse, NY, United States
- Department of Microbiology and Immunology, SUNY Upstate Medical University, Syracuse, NY, United States
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17
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Rosà R, Tagliapietra V, Manica M, Arnoldi D, Hauffe HC, Rossi C, Rosso F, Henttonen H, Rizzoli A. Changes in host densities and co-feeding pattern efficiently predict tick-borne encephalitis hazard in an endemic focus in northern Italy. Int J Parasitol 2019; 49:779-787. [DOI: 10.1016/j.ijpara.2019.05.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 05/03/2019] [Accepted: 05/08/2019] [Indexed: 10/26/2022]
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18
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Yakass MB, Franco D, Quaye O. Suppressors of Cytokine Signaling and Protein Inhibitors of Activated Signal Transducer and Activator of Transcriptions As Therapeutic Targets in Flavivirus Infections. J Interferon Cytokine Res 2019; 40:1-18. [PMID: 31436502 DOI: 10.1089/jir.2019.0097] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Flaviviruses cause significant human diseases putting more than 400 million people at risk annually worldwide. Because of migration and improved transportation, these viruses can be found on all continents (except Antarctica). Although a majority of the viruses are endemic in the tropics, a few [West Nile virus (WNV) and tick-borne encephalitis virus (TBEV)] have shown endemicity in Europe and North America. Currently, there are vaccines for the Yellow fever virus, Japanese encephalitis virus, and TBEV, but there is no effective vaccine and/or therapy against all other flaviviruses. Although there are intensive efforts to develop vaccines for Zika viruses, dengue viruses, and WNVs, there is the need for alternative or parallel antiviral therapeutic approaches. Suppressors of cytokine signaling (SOCS) and protein inhibitors of activated signal transducer and activator of transcription (STATs; PIAS), both regulatory proteins of the Janus kinase/STAT signaling pathway, have been explored as therapeutic targets in herpes simplex and vaccinia viruses, as well as in cancer therapy. In this review, we briefly describe the function of SOCS and PIAS and their therapeutic potential in flaviviral infections. [Figure: see text].
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Affiliation(s)
- Michael Bright Yakass
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, Accra, Ghana.,Department of Biochemistry, Cell and Molecular Biology, University of Ghana, Accra, Ghana
| | | | - Osbourne Quaye
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, Accra, Ghana.,Department of Biochemistry, Cell and Molecular Biology, University of Ghana, Accra, Ghana
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Michelitsch A, Wernike K, Klaus C, Dobler G, Beer M. Exploring the Reservoir Hosts of Tick-Borne Encephalitis Virus. Viruses 2019; 11:E669. [PMID: 31336624 PMCID: PMC6669706 DOI: 10.3390/v11070669] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 07/17/2019] [Accepted: 07/19/2019] [Indexed: 12/20/2022] Open
Abstract
Tick-borne encephalitis virus (TBEV) is an important arbovirus, which is found across large parts of Eurasia and is considered to be a major health risk for humans. Like any other arbovirus, TBEV relies on complex interactions between vectors, reservoir hosts, and the environment for successful virus circulation. Hard ticks are the vectors for TBEV, transmitting the virus to a variety of animals. The importance of these animals in the lifecycle of TBEV is still up for debate. Large woodland animals seem to have a positive influence on virus circulation by providing a food source for adult ticks; birds are suspected to play a role in virus distribution. Bank voles and yellow-necked mice are often referred to as classical virus reservoirs, but this statement lacks strong evidence supporting their highlighted role. Other small mammals (e.g., insectivores) may also play a crucial role in virus transmission, not to mention the absence of any suspected reservoir host for non-European endemic regions. Theories highlighting the importance of the co-feeding transmission route go as far as naming ticks themselves as the true reservoir for TBEV, and mammalian hosts as a mere bridge for transmission. A deeper insight into the virus reservoir could lead to a better understanding of the development of endemic regions. The spatial distribution of TBEV is constricted to certain areas, forming natural foci that can be restricted to sizes of merely 500 square meters. The limiting factors for their occurrence are largely unknown, but a possible influence of reservoir hosts on the distribution pattern of TBE is discussed. This review aims to give an overview of the multiple factors influencing the TBEV transmission cycle, focusing on the role of virus reservoirs, and highlights the questions that are waiting to be further explored.
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Affiliation(s)
- Anna Michelitsch
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Südufer 10, 17493 Greifswald-Insel Riems, Germany
| | - Kerstin Wernike
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Südufer 10, 17493 Greifswald-Insel Riems, Germany
| | - Christine Klaus
- Institute for Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut, Naumburger Str. 96a, 07743 Jena, Germany
| | - Gerhard Dobler
- Bundeswehr Institute of Microbiology, German Center of Infection Research (DZIF) partner site Munich, Neuherbergstraße 11, 80937 München, Germany
| | - Martin Beer
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Südufer 10, 17493 Greifswald-Insel Riems, Germany.
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20
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Rego ROM, Trentelman JJA, Anguita J, Nijhof AM, Sprong H, Klempa B, Hajdusek O, Tomás-Cortázar J, Azagi T, Strnad M, Knorr S, Sima R, Jalovecka M, Fumačová Havlíková S, Ličková M, Sláviková M, Kopacek P, Grubhoffer L, Hovius JW. Counterattacking the tick bite: towards a rational design of anti-tick vaccines targeting pathogen transmission. Parasit Vectors 2019; 12:229. [PMID: 31088506 PMCID: PMC6518728 DOI: 10.1186/s13071-019-3468-x] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 04/29/2019] [Indexed: 02/07/2023] Open
Abstract
Hematophagous arthropods are responsible for the transmission of a variety of pathogens that cause disease in humans and animals. Ticks of the Ixodes ricinus complex are vectors for some of the most frequently occurring human tick-borne diseases, particularly Lyme borreliosis and tick-borne encephalitis virus (TBEV). The search for vaccines against these diseases is ongoing. Efforts during the last few decades have primarily focused on understanding the biology of the transmitted viruses, bacteria and protozoans, with the goal of identifying targets for intervention. Successful vaccines have been developed against TBEV and Lyme borreliosis, although the latter is no longer available for humans. More recently, the focus of intervention has shifted back to where it was initially being studied which is the vector. State of the art technologies are being used for the identification of potential vaccine candidates for anti-tick vaccines that could be used either in humans or animals. The study of the interrelationship between ticks and the pathogens they transmit, including mechanisms of acquisition, persistence and transmission have come to the fore, as this knowledge may lead to the identification of critical elements of the pathogens' life-cycle that could be targeted by vaccines. Here, we review the status of our current knowledge on the triangular relationships between ticks, the pathogens they carry and the mammalian hosts, as well as methods that are being used to identify anti-tick vaccine candidates that can prevent the transmission of tick-borne pathogens.
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Affiliation(s)
- Ryan O. M. Rego
- Biology Centre, Institute of Parasitology, Czech Academy of Sciences, Branišovská 31, 37005 Ceske Budejovice, Czech Republic
| | - Jos J. A. Trentelman
- Amsterdam UMC, Location AMC, Center for Experimental and Molecular Medicine, Amsterdam, The Netherlands
| | - Juan Anguita
- CIC bioGUNE, 48160 Derio, Spain
- Ikerbasque, Basque Foundation for Science, 48012 Bilbao, Spain
| | - Ard M. Nijhof
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Hein Sprong
- Centre for Zoonoses and Environmental Microbiology, Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - Boris Klempa
- Institute of Virology, Biomedical Research Center of the Slovak Academy of Sciences, Bratislava, Slovakia
| | - Ondrej Hajdusek
- Biology Centre, Institute of Parasitology, Czech Academy of Sciences, Branišovská 31, 37005 Ceske Budejovice, Czech Republic
| | | | - Tal Azagi
- Centre for Zoonoses and Environmental Microbiology, Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - Martin Strnad
- Biology Centre, Institute of Parasitology, Czech Academy of Sciences, Branišovská 31, 37005 Ceske Budejovice, Czech Republic
- Faculty of Science, University of South Bohemia, Branišovská 31, 37005 Ceske Budejovice, Czech Republic
| | - Sarah Knorr
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Radek Sima
- Biology Centre, Institute of Parasitology, Czech Academy of Sciences, Branišovská 31, 37005 Ceske Budejovice, Czech Republic
| | - Marie Jalovecka
- Biology Centre, Institute of Parasitology, Czech Academy of Sciences, Branišovská 31, 37005 Ceske Budejovice, Czech Republic
- Faculty of Science, University of South Bohemia, Branišovská 31, 37005 Ceske Budejovice, Czech Republic
| | - Sabína Fumačová Havlíková
- Institute of Virology, Biomedical Research Center of the Slovak Academy of Sciences, Bratislava, Slovakia
| | - Martina Ličková
- Institute of Virology, Biomedical Research Center of the Slovak Academy of Sciences, Bratislava, Slovakia
| | - Monika Sláviková
- Institute of Virology, Biomedical Research Center of the Slovak Academy of Sciences, Bratislava, Slovakia
| | - Petr Kopacek
- Biology Centre, Institute of Parasitology, Czech Academy of Sciences, Branišovská 31, 37005 Ceske Budejovice, Czech Republic
- Faculty of Science, University of South Bohemia, Branišovská 31, 37005 Ceske Budejovice, Czech Republic
| | - Libor Grubhoffer
- Biology Centre, Institute of Parasitology, Czech Academy of Sciences, Branišovská 31, 37005 Ceske Budejovice, Czech Republic
- Faculty of Science, University of South Bohemia, Branišovská 31, 37005 Ceske Budejovice, Czech Republic
| | - Joppe W. Hovius
- Amsterdam UMC, Location AMC, Center for Experimental and Molecular Medicine, Amsterdam, The Netherlands
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Tick saliva and its role in pathogen transmission. Wien Klin Wochenschr 2019; 135:165-176. [PMID: 31062185 PMCID: PMC10118219 DOI: 10.1007/s00508-019-1500-y] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 04/09/2019] [Indexed: 12/31/2022]
Abstract
Tick saliva is a complex mixture of peptidic and non-peptidic molecules that aid engorgement. The composition of tick saliva changes as feeding progresses and the tick counters the dynamic host response. Ixodid ticks such as Ixodes ricinus, the most important tick species in Europe, transmit numerous pathogens that cause debilitating diseases, e.g. Lyme borreliosis and tick-borne encephalitis. Tick-borne pathogens are transmitted in tick saliva during blood feeding; however, saliva is not simply a medium enabling pathogen transfer. Instead, tick-borne pathogens exploit saliva-induced modulation of host responses to promote their transmission and infection, so-called saliva-assisted transmission (SAT). Characterization of the saliva factors that facilitate SAT is an active area of current research. Besides providing new insights into how tick-borne pathogens survive in nature, the research is opening new avenues for vaccine development.
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22
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Belova OA, Kholodilov IS, Litov AG, Karganova GG. The Ability of Ixodid Ticks (Acari: Ixodidae) to Support Reproduction of the Tick-Borne Encephalitis Virus. ACTA ACUST UNITED AC 2019. [DOI: 10.1134/s0013873818090142] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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23
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Dissecting Flavivirus Biology in Salivary Gland Cultures from Fed and Unfed Ixodes scapularis (Black-Legged Tick). mBio 2019; 10:mBio.02628-18. [PMID: 30696737 PMCID: PMC6355982 DOI: 10.1128/mbio.02628-18] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Tick-borne flaviviruses (TBFVs) are responsible for more than 15,000 human disease cases each year, and Powassan virus lineage 2 (POWV-L2) deer tick virus has been a reemerging threat in North America over the past 20 years. Rapid transmission of TBFVs in particular emphasizes the importance of preventing tick bites, the difficulty in developing countermeasures to prevent transmission, and the importance of understanding TBFV infection in tick salivary glands (SGs). Tick blood feeding is responsible for phenomenal physiological changes and is associated with changes in TBFV multiplication within the tick and in SGs. Using SG cultures from Ixodes scapularis female ticks, the primary aims of this study were to identify cellular localization of virus-like particles in acini of infected SGs from fed and unfed ticks, localization of TBFV infection in infected SGs from fed ticks, and a tick transcript (with associated metabolic function) involved in POWV-L2 infection in SG cultures. The Ixodes scapularis tick transmits a number of pathogens, including tick-borne flaviviruses (TBFVs). In the United States, confirmed human infections with the Powassan virus (POWV) TBFV have a fatality rate of ∼10% and are increasing in incidence. Tick salivary glands (SGs) serve as an organ barrier to TBFV transmission, and little is known regarding the location of TBFV infection in SGs from fed ticks. Previous studies showed I. scapularis vanin (VNN) involved with TBFV infection of I. scapularis ISE6 embryonic cells, suggesting a potential role for this gene. The overall goal of this study was to use SG cultures to compare data on TBFV biology in SGs from fully engorged, replete (fed) ticks and from unfed ticks. TBFV multiplication was higher in SGs from fed ticks than in those from unfed ticks. Virus-like particles were observed only in granular acini of SGs from unfed ticks. The location of TBFV infection of SGs from fed ticks was observed in cells lining lobular ducts and trachea but not observed in acini. Transcript knockdown of VNN decreased POWV multiplication in infected SG cultures from both fed and unfed ticks. This work was the first to identify localization of TBFV multiplication in SG cultures from a fed tick and a tick transcript important for POWV multiplication in the tick SG, an organ critical for TBFV transmission. This research exemplifies the use of SG cultures in deciphering TBFV biology in the tick and as a translational tool for screening and identifying potential tick genes as potential countermeasure targets.
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Talactac MR, Hernandez EP, Fujisaki K, Tanaka T. A Continuing Exploration of Tick-Virus Interactions Using Various Experimental Viral Infections of Hard Ticks. Front Physiol 2018; 9:1728. [PMID: 30564140 PMCID: PMC6288443 DOI: 10.3389/fphys.2018.01728] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 11/16/2018] [Indexed: 01/07/2023] Open
Abstract
To fully unravel the ixodid ticks’ role as vectors of viral pathogens, their susceptibility to new control measures, and their ability to develop acaricide resistance, acclimatization of ticks under laboratory conditions is greatly needed. However, the unique and complicated feeding behavior of these ticks compared to that of other hematophagous arthropods requires efficient and effective techniques to infect them with tick-borne viruses (TBVs). In addition, relatively expensive maintenance of animals for blood feeding and associated concerns about animal welfare critically limit our understanding of TBVs. This mini review aims to summarize the current knowledge about the artificial infection of hard ticks with viral pathogens, which is currently used to elucidate virus transmission and vector competence and to discover immune modulators related to tick–virus interactions. This review will also present the advantages and limitations of the current techniques for tick infection. Fortunately, new artificial techniques arise, and the limitations of current protocols are greatly reduced as researchers continuously improve, streamline, and standardize the laboratory procedures to lower cost and produce better adoptability. In summary, convenient and low-cost techniques to study the interactions between ticks and TBVs provide a great opportunity to identify new targets for the future control of TBVs.
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Affiliation(s)
- Melbourne Rio Talactac
- Department of Clinical and Population Health, College of Veterinary Medicine and Biomedical Sciences, Cavite State University, Cavite, Philippines.,Laboratory of Infectious Diseases, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan
| | - Emmanuel P Hernandez
- Laboratory of Infectious Diseases, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan
| | - Kozo Fujisaki
- National Agriculture and Food Research Organization, Tsukuba, Japan
| | - Tetsuya Tanaka
- Laboratory of Infectious Diseases, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan
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25
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Detection and molecular characterization of Mogiana tick virus (MGTV) in Rhipicephalus microplus collected from cattle in a savannah area, Uberlândia, Brazil. Ticks Tick Borne Dis 2018; 10:162-165. [PMID: 30348511 DOI: 10.1016/j.ttbdis.2018.10.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 10/06/2018] [Accepted: 10/10/2018] [Indexed: 02/08/2023]
Abstract
In Brazil, recent studies have reported viruses detected in ticks with pathogenic potential in vertebrate hosts. Ticks of the species Rhipicephalus microplus collected from bovines in a savannah area were tested by RT-PCR for the presence of RNA targetting a segment of NS3-like protein gene of Mogiana tick virus, a member of the recently-described Jingmenvirus group. Amplification with size similar to the expected was observed with 25% (7/28) RNA samples of ticks that were collected from 39% (7/18) of the bovines. Nucleotide sequence analysis of three PCR products revealed divergence that varied from 3.3 to 5.0% in a single farm. Although Jingmen tick virus, another member belonging to the Jingmenvirus group, has been detected in human patients with Crimean-Congo hemorrhagic fever in Kosovo, whether or not MGTV causes disease in cattle and other animals remains to be investigated.
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26
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Klitting R, Gould EA, Paupy C, de Lamballerie X. What Does the Future Hold for Yellow Fever Virus? (I). Genes (Basel) 2018; 9:E291. [PMID: 29890711 PMCID: PMC6027470 DOI: 10.3390/genes9060291] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 06/04/2018] [Accepted: 06/06/2018] [Indexed: 01/14/2023] Open
Abstract
The recent resurgence of yellow fever virus (YFV) activity in the tropical regions of Africa and South America has sparked renewed interest in this infamous arboviral disease. Yellow fever virus had been a human plague for centuries prior to the identification of its urban transmission vector, the Aedes (Stegomyia) aegypti (Linnaeus) mosquito species, and the development of an efficient live-attenuated vaccine, the YF-17D strain. The combination of vector-control measures and vaccination campaigns drastically reduced YFV incidence in humans on many occasions, but the virus never ceased to circulate in the forest, through its sylvatic invertebrate vector(s) and vertebrate host(s). Outbreaks recently reported in Central Africa (2015⁻2016) and Brazil (since late 2016), reached considerable proportions in terms of spatial distribution and total numbers of cases, with multiple exports, including to China. In turn, questions about the likeliness of occurrence of large urban YFV outbreaks in the Americas or of a successful import of YFV to Asia are currently resurfacing. This two-part review describes the current state of knowledge and gaps regarding the molecular biology and transmission dynamics of YFV, along with an overview of the tools that can be used to manage the disease at individual, local and global levels.
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Affiliation(s)
- Raphaëlle Klitting
- Unité des Virus Émergents (UVE: Aix-Marseille Université, IRD 190, Inserm 1207, IHU Méditerranée Infection), 13385 Marseille Cedex 05, France.
| | - Ernest A Gould
- Unité des Virus Émergents (UVE: Aix-Marseille Université, IRD 190, Inserm 1207, IHU Méditerranée Infection), 13385 Marseille Cedex 05, France.
| | - Christophe Paupy
- UMR Maladies Infectieuses et Vecteurs: Écologie, Génétique Évolution et Contrôle (MIVEGEC: IRD, CNRS, Université Montpellier), 34394 Montpellier, France.
| | - Xavier de Lamballerie
- Unité des Virus Émergents (UVE: Aix-Marseille Université, IRD 190, Inserm 1207, IHU Méditerranée Infection), 13385 Marseille Cedex 05, France.
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27
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Thangamani S, Hermance ME, Santos RI, Slovak M, Heinze D, Widen SG, Kazimirova M. Transcriptional Immunoprofiling at the Tick-Virus-Host Interface during Early Stages of Tick-Borne Encephalitis Virus Transmission. Front Cell Infect Microbiol 2017; 7:494. [PMID: 29250492 PMCID: PMC5716978 DOI: 10.3389/fcimb.2017.00494] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 11/15/2017] [Indexed: 12/26/2022] Open
Abstract
Emerging and re-emerging diseases transmitted by blood feeding arthropods are significant global public health problems. Ticks transmit the greatest variety of pathogenic microorganisms of any blood feeding arthropod. Infectious agents transmitted by ticks are delivered to the vertebrate host together with saliva at the bite site. Tick salivary glands produce complex cocktails of bioactive molecules that facilitate blood feeding and pathogen transmission by modulating host hemostasis, pain/itch responses, wound healing, and both innate and adaptive immunity. In this study, we utilized Illumina Next Generation Sequencing to characterize the transcriptional immunoprofile of cutaneous immune responses to Ixodes ricinus transmitted tick-borne encephalitis virus (TBEV). A comparative immune gene expression analysis of TBEV-infected and uninfected tick feeding sites was performed. Our analysis reveals that ticks create an inflammatory environment at the bite site during the first 3 h of feeding, and significant differences in host responses were observed between TBEV-infected and uninfected tick feeding. Gene-expression analysis reveals modulation of inflammatory genes after 1 and 3 h of TBEV-infected tick feeding. Transcriptional levels of genes specific to chemokines and cytokines indicated a neutrophil-dominated immune response. Immunohistochemistry of the tick feeding site revealed that mononuclear phagocytes and fibroblasts are the primary target cells for TBEV infection and did not detect TBEV antigens in neutrophils. Together, the transcriptional and immunohistochemistry results suggest that early cutaneous host responses to TBEV-infected tick feeding are more inflammatory than expected and highlight the importance of inflammatory chemokine and cytokine pathways in tick-borne flavivirus transmission.
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Affiliation(s)
- Saravanan Thangamani
- Department of Pathology, The University of Texas Medical Branch, Galveston, TX, United States.,Institute for Human Infections and Immunity, The University of Texas Medical Branch, Galveston, TX, United States.,Center for Tropical Diseases, The University of Texas Medical Branch, Galveston, TX, United States
| | - Meghan E Hermance
- Department of Pathology, The University of Texas Medical Branch, Galveston, TX, United States
| | - Rodrigo I Santos
- Department of Pathology, The University of Texas Medical Branch, Galveston, TX, United States
| | - Mirko Slovak
- Institute of Zoology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Dar Heinze
- Department of Surgery, Center for Regenerative Medicine, Boston University and Boston Medical Center, Boston, MA, United States
| | - Steven G Widen
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX, United States
| | - Maria Kazimirova
- Institute of Zoology, Slovak Academy of Sciences, Bratislava, Slovakia
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28
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Grabowski JM, Tsetsarkin KA, Long D, Scott DP, Rosenke R, Schwan TG, Mlera L, Offerdahl DK, Pletnev AG, Bloom ME. Flavivirus Infection of Ixodes scapularis (Black-Legged Tick) Ex Vivo Organotypic Cultures and Applications for Disease Control. mBio 2017; 8:e01255-17. [PMID: 28830948 PMCID: PMC5565970 DOI: 10.1128/mbio.01255-17] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 07/25/2017] [Indexed: 12/21/2022] Open
Abstract
Ixodes scapularis ticks transmit many infectious agents that cause disease, including tick-borne flaviviruses (TBFVs). TBFV infections cause thousands of human encephalitis cases worldwide annually. In the United States, human TBFV infections with Powassan virus (POWV) are increasing and have a fatality rate of 10 to 30%. Additionally, Langat virus (LGTV) is a TBFV of low neurovirulence and is used as a model TBFV. TBFV replication and dissemination within I. scapularis organs are poorly characterized, and a deeper understanding of virus biology in this vector may inform effective countermeasures to reduce TBFV transmission. Here, we describe short-term, I. scapularis organ culture models of TBFV infection. Ex vivo organs were metabolically active for 9 to 10 days and were permissive to LGTV and POWV replication. Imaging and videography demonstrated replication and spread of green fluorescent protein-expressing LGTV in the organs. Immunohistochemical staining confirmed LGTV envelope and POWV protein synthesis within the infected organs. LGTV- and POWV-infected organs produced infectious LGTV and POWV; thus, the ex vivo cultures were suitable for study of virus replication in individual organs. LGTV- and POWV-infected midgut and salivary glands were subjected to double-stranded RNA (dsRNA) transfection with dsRNA to the LGTV 3' untranslated region (UTR), which reduced infectious LGTV and POWV replication, providing a proof-of-concept use of RNA interference in I. scapularis organ cultures to study the effects on TBFV replication. The results contribute important information on TBFV localization within ex vivo I. scapularis organs and provide a significant translational tool for evaluating recombinant, live vaccine candidates and potential tick transcripts and proteins for possible therapeutic use and vaccine development to reduce TBFV transmission.IMPORTANCE Tick-borne flavivirus (TBFV) infections cause neurological and/or hemorrhagic disease in humans worldwide. There are currently no licensed therapeutics or vaccines against Powassan virus (POWV), the only TBFV known to circulate in North America. Evaluating tick vector targets for antitick vaccines directed at reducing TBFV infection within the arthropod vector is a critical step in identifying efficient approaches to controlling TBFV transmission. This study characterized infection of female Ixodes scapularis tick organ cultures of midgut, salivary glands, and synganglion with the low-neurovirulence Langat virus (LGTV) and the more pathogenic POWV. Cell types of specific organs were susceptible to TBFV infection, and a difference in LGTV and POWV replication was noted in TBFV-infected organs. This tick organ culture model of TBFV infection will be useful for various applications, such as screening of tick endogenous dsRNA corresponding to potential control targets within midgut and salivary glands to confirm restriction of TBFV infection.
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Affiliation(s)
- Jeffrey M Grabowski
- Biology of Vector-Borne Viruses Section, Laboratory of Virology, Rocky Mountain Laboratories, NIAID, NIH, Hamilton, Montana, USA
| | - Konstantin A Tsetsarkin
- Neurotropic Flaviviruses Section, Laboratory of Infectious Diseases, NIAID, NIH, Bethesda, Maryland, USA
| | - Dan Long
- Rocky Mountain Veterinary Branch, Rocky Mountain Laboratories, NIAID, NIH, Hamilton, Montana, USA
| | - Dana P Scott
- Rocky Mountain Veterinary Branch, Rocky Mountain Laboratories, NIAID, NIH, Hamilton, Montana, USA
| | - Rebecca Rosenke
- Rocky Mountain Veterinary Branch, Rocky Mountain Laboratories, NIAID, NIH, Hamilton, Montana, USA
| | - Tom G Schwan
- Laboratory of Zoonotic Pathogens, Rocky Mountain Laboratories, NIAID, NIH, Hamilton, Montana, USA
| | - Luwanika Mlera
- Biology of Vector-Borne Viruses Section, Laboratory of Virology, Rocky Mountain Laboratories, NIAID, NIH, Hamilton, Montana, USA
| | - Danielle K Offerdahl
- Biology of Vector-Borne Viruses Section, Laboratory of Virology, Rocky Mountain Laboratories, NIAID, NIH, Hamilton, Montana, USA
| | - Alexander G Pletnev
- Neurotropic Flaviviruses Section, Laboratory of Infectious Diseases, NIAID, NIH, Bethesda, Maryland, USA
| | - Marshall E Bloom
- Biology of Vector-Borne Viruses Section, Laboratory of Virology, Rocky Mountain Laboratories, NIAID, NIH, Hamilton, Montana, USA
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29
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Kazimírová M, Thangamani S, Bartíková P, Hermance M, Holíková V, Štibrániová I, Nuttall PA. Tick-Borne Viruses and Biological Processes at the Tick-Host-Virus Interface. Front Cell Infect Microbiol 2017; 7:339. [PMID: 28798904 PMCID: PMC5526847 DOI: 10.3389/fcimb.2017.00339] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 07/11/2017] [Indexed: 01/08/2023] Open
Abstract
Ticks are efficient vectors of arboviruses, although less than 10% of tick species are known to be virus vectors. Most tick-borne viruses (TBV) are RNA viruses some of which cause serious diseases in humans and animals world-wide. Several TBV impacting human or domesticated animal health have been found to emerge or re-emerge recently. In order to survive in nature, TBV must infect and replicate in both vertebrate and tick cells, representing very different physiological environments. Information on molecular mechanisms that allow TBV to switch between infecting and replicating in tick and vertebrate cells is scarce. In general, ticks succeed in completing their blood meal thanks to a plethora of biologically active molecules in their saliva that counteract and modulate different arms of the host defense responses (haemostasis, inflammation, innate and acquired immunity, and wound healing). The transmission of TBV occurs primarily during tick feeding and is a complex process, known to be promoted by tick saliva constituents. However, the underlying molecular mechanisms of TBV transmission are poorly understood. Immunomodulatory properties of tick saliva helping overcome the first line of defense to injury and early interactions at the tick-host skin interface appear to be essential in successful TBV transmission and infection of susceptible vertebrate hosts. The local host skin site of tick attachment, modulated by tick saliva, is an important focus of virus replication. Immunomodulation of the tick attachment site also promotes co-feeding transmission of viruses from infected to non-infected ticks in the absence of host viraemia (non-viraemic transmission). Future research should be aimed at identification of the key tick salivary molecules promoting virus transmission, and a molecular description of tick-host-virus interactions and of tick-mediated skin immunomodulation. Such insights will enable the rationale design of anti-tick vaccines that protect against disease caused by tick-borne viruses.
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Affiliation(s)
- Mária Kazimírová
- Department of Medical Zoology, Institute of Zoology, Slovak Academy of SciencesBratislava, Slovakia
| | - Saravanan Thangamani
- Department of Pathology, University of Texas Medical BranchGalveston, TX, United States
- Institute for Human Infections and Immunity, University of Texas Medical BranchGalveston, TX, United States
- Center for Tropical Diseases, University of Texas Medical BranchGalveston, TX, United States
| | - Pavlína Bartíková
- Biomedical Research Center, Institute of Virology, Slovak Academy of SciencesBratislava, Slovakia
| | - Meghan Hermance
- Department of Pathology, University of Texas Medical BranchGalveston, TX, United States
- Institute for Human Infections and Immunity, University of Texas Medical BranchGalveston, TX, United States
- Center for Tropical Diseases, University of Texas Medical BranchGalveston, TX, United States
| | - Viera Holíková
- Biomedical Research Center, Institute of Virology, Slovak Academy of SciencesBratislava, Slovakia
| | - Iveta Štibrániová
- Biomedical Research Center, Institute of Virology, Slovak Academy of SciencesBratislava, Slovakia
| | - Patricia A. Nuttall
- Department of Zoology, University of OxfordOxford, United Kingdom
- Centre for Ecology and HydrologyWallingford, United Kingdom
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30
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Holbrook MR. Historical Perspectives on Flavivirus Research. Viruses 2017; 9:E97. [PMID: 28468299 PMCID: PMC5454410 DOI: 10.3390/v9050097] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 04/13/2017] [Accepted: 04/21/2017] [Indexed: 12/21/2022] Open
Abstract
The flaviviruses are small single-stranded RNA viruses that are typically transmitted by mosquito or tick vectors. These "arboviruses" are found around the world and account for a significant number of cases of human disease. The flaviviruses cause diseases ranging from mild or sub-clinical infections to lethal hemorrhagic fever or encephalitis. In many cases, survivors of neurologic flavivirus infections suffer long-term debilitating sequelae. Much like the emergence of West Nile virus in the United States in 1999, the recent emergence of Zika virus in the Americas has significantly increased the awareness of mosquito-borne viruses. The diseases caused by several flaviviruses have been recognized for decades, if not centuries. However, there is still a lot that is unknown about the flaviviruses as the recent experience with Zika virus has taught us. The objective of this review is to provide a general overview and some historical perspective on several flaviviruses that cause significant human disease. In addition, available medical countermeasures and significant gaps in our understanding of flavivirus biology are also discussed.
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Affiliation(s)
- Michael R Holbrook
- NIAID Integrated Research Facility, 8200 Research Plaza, Ft. Detrick, Frederick, MD 21702, USA.
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31
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Tick-Borne Encephalitis Virus Structural Proteins Are the Primary Viral Determinants of Non-Viraemic Transmission between Ticks whereas Non-Structural Proteins Affect Cytotoxicity. PLoS One 2016; 11:e0158105. [PMID: 27341437 PMCID: PMC4920422 DOI: 10.1371/journal.pone.0158105] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 06/12/2016] [Indexed: 02/02/2023] Open
Abstract
Over 50 million humans live in areas of potential exposure to tick-borne encephalitis virus (TBEV). The disease exhibits an estimated 16,000 cases recorded annually over 30 European and Asian countries. Conventionally, TBEV transmission to Ixodes spp. ticks occurs whilst feeding on viraemic animals. However, an alternative mechanism of non-viraemic transmission (NVT) between infected and uninfected ticks co-feeding on the same transmission-competent host, has also been demonstrated. Here, using laboratory-bred I. ricinus ticks, we demonstrate low and high efficiency NVT for TBEV strains Vasilchenko (Vs) and Hypr, respectively. These virus strains share high sequence similarity but are classified as two TBEV subtypes. The Vs strain is a Siberian subtype, naturally associated with I. persulcatus ticks whilst the Hypr strain is a European subtype, transmitted by I. ricinus ticks. In mammalian cell culture (porcine kidney cell line PS), Vs and Hypr induce low and high cytopathic effects (cpe), respectively. Using reverse genetics, we engineered a range of viable Vs/Hypr chimaeric strains, with substituted genes. No significant differences in replication rate were detected between wild-type and chimaeric viruses in cell culture. However, the chimaeric strain Vs[Hypr str] (Hypr structural and Vs non-structural genomic regions) demonstrated high efficiency NVT in I. ricinus whereas the counterpart Hypr[Vs str] was not transmitted by NVT, indicating that the virion structural proteins largely determine TBEV NVT transmission efficiency between ticks. In contrast, in cell culture, the extent of cpe was largely determined by the non-structural region of the TBEV genome. Chimaeras with Hypr non-structural genes were more cytotoxic for PS cells when compared with Vs genome-based chimaeras.
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32
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Althouse BM, Hanley KA. The tortoise or the hare? Impacts of within-host dynamics on transmission success of arthropod-borne viruses. Philos Trans R Soc Lond B Biol Sci 2016; 370:rstb.2014.0299. [PMID: 26150665 DOI: 10.1098/rstb.2014.0299] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Arthropod-borne viruses (arboviruses) are maintained in a cycle of alternating transmission between vertebrate hosts and arthropod vectors. Arboviruses possess RNA genomes capable of rapid diversification and adaptation, and the between-host trade-offs inherent to host alternation impose well-documented constraints on arbovirus evolution. Here, we investigate the less well-studied within-host trade-offs that shape arbovirus replication dynamics and transmission. Arboviruses generally establish lifelong infection in vectors but transient infection of variable magnitude (i.e. peak virus concentration) and duration in vertebrate hosts. In the majority of experimental infections of vertebrate hosts, both the magnitude and duration of arbovirus replication depended upon the dose of virus administered, with increasing dose resulting in greater magnitude but shorter duration of viraemia. This pattern suggests that the vertebrate immune response imposes a trade-off between the height and breadth of the virus replication curve. To investigate the impact of this trade-off on transmission, we used a simple modelling approach to contrast the effect of 'tortoise' (low magnitude, long duration viraemia) and 'hare' (high magnitude, short duration viraemia) arbovirus replication strategies on transmission. This model revealed that, counter to previous theory, arboviruses that adopt a tortoise strategy have higher rates of persistence in both host and vector populations.
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Affiliation(s)
- Benjamin M Althouse
- Santa Fe Institute, Santa Fe, NM 87501, USA Department of Biology, New Mexico State University, Las Cruces, NM 88003, USA Institute for Disease Modeling, Bellevue, WA 98005, USA
| | - Kathryn A Hanley
- Department of Biology, New Mexico State University, Las Cruces, NM 88003, USA
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33
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Liang G, Gao X, Gould EA. Factors responsible for the emergence of arboviruses; strategies, challenges and limitations for their control. Emerg Microbes Infect 2015; 4:e18. [PMID: 26038768 PMCID: PMC4395659 DOI: 10.1038/emi.2015.18] [Citation(s) in RCA: 130] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 02/13/2015] [Accepted: 02/16/2015] [Indexed: 12/25/2022]
Abstract
Slave trading of Africans to the Americas, during the 16th to the 19th century was responsible for the first recorded emergence in the New World of two arthropod-borne viruses (arboviruses), yellow fever virus and dengue virus. Many other arboviruses have since emerged from their sylvatic reservoirs and dispersed globally due to evolving factors that include anthropological behaviour, commercial transportation and land-remediation. Here, we outline some characteristics of these highly divergent arboviruses, including the variety of life cycles they have developed and the mechanisms by which they have adapted to evolving changes in habitat and host availability. We cite recent examples of virus emergence that exemplify how arboviruses have exploited the consequences of the modern human lifestyle. Using our current understanding of these viruses, we also attempt to demonstrate some of the limitations encountered in developing control strategies to reduce the impact of future emerging arbovirus diseases. Finally, we present recommendations for development by an international panel of experts reporting directly to World Health Organization, with the intention of providing internationally acceptable guidelines for improving emerging arbovirus disease control strategies. Success in these aims should alleviate the suffering and costs encountered during recent decades when arboviruses have emerged from their sylvatic environment.
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Affiliation(s)
- Guodong Liang
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Centre for Disease Control and Prevention , Beijing 102206, China ; Collaborative Innovation Centre for Diagnosis and Treatment of Infectious Diseases , Hangzhou 310003, Zhejiang province, China
| | - Xiaoyan Gao
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Centre for Disease Control and Prevention , Beijing 102206, China ; Collaborative Innovation Centre for Diagnosis and Treatment of Infectious Diseases , Hangzhou 310003, Zhejiang province, China
| | - Ernest A Gould
- Aix Marseille University, IRD French Institute of Research for Development, EHESP French School of Public Health, EPV UMR_D 190 "Emergence des Pathologies Virales" , Marseille 13385, France ; Centre for Ecology & Hydrology , Oxford OX1 3SR, United Kingdom
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34
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Brites-Neto J, Duarte KMR, Martins TF. Tick-borne infections in human and animal population worldwide. Vet World 2015; 8:301-15. [PMID: 27047089 PMCID: PMC4774835 DOI: 10.14202/vetworld.2015.301-315] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 01/20/2015] [Accepted: 01/25/2015] [Indexed: 12/30/2022] Open
Abstract
The abundance and activity of ectoparasites and its hosts are affected by various abiotic factors, such as climate and other organisms (predators, pathogens and competitors) presenting thus multiples forms of association (obligate to facultative, permanent to intermittent and superficial to subcutaneous) developed during long co-evolving processes. Ticks are ectoparasites widespread globally and its eco epidemiology are closely related to the environmental conditions. They are obligatory hematophagous ectoparasites and responsible as vectors or reservoirs at the transmission of pathogenic fungi, protozoa, viruses, rickettsia and others bacteria during their feeding process on the hosts. Ticks constitute the second vector group that transmit the major number of pathogens to humans and play a role primary for animals in the process of diseases transmission. Many studies on bioecology of ticks, considering the information related to their population dynamics, to the host and the environment, comes possible the application and efficiency of tick control measures in the prevention programs of vector-borne diseases. In this review were considered some taxonomic, morphological, epidemiological and clinical fundamental aspects related to the tick-borne infections that affect human and animal populations.
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Affiliation(s)
| | - Keila Maria Roncato Duarte
- Department of Genetics and Animal Reproduction, Institute of Animal Science, Nova Odessa, São Paulo, Brazil
| | - Thiago Fernandes Martins
- Department of Preventive Veterinary Medicine, Faculty of Veterinary Medicine and Animal Sciences, University of São Paulo, São Paulo, Brazil
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