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Koutantou M, Drancourt M, Angelakis E. Prevalence of Lyme Disease and Relapsing Fever Borrelia spp. in Vectors, Animals, and Humans within a One Health Approach in Mediterranean Countries. Pathogens 2024; 13:512. [PMID: 38921809 PMCID: PMC11206712 DOI: 10.3390/pathogens13060512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Revised: 06/05/2024] [Accepted: 06/10/2024] [Indexed: 06/27/2024] Open
Abstract
The genus Borrelia has been divided into Borreliella spp., which can cause Lyme Disease (LD), and Borrelia spp., which can cause Relapsing Fever (RF). The distribution of genus Borrelia has broadened due to factors such as climate change, alterations in land use, and enhanced human and animal mobility. Consequently, there is an increasing necessity for a One Health strategy to identify the key components in the Borrelia transmission cycle by monitoring the human-animal-environment interactions. The aim of this study is to summarize all accessible data to increase our understanding and provide a comprehensive overview of Borrelia distribution in the Mediterranean region. Databases including PubMed, Google Scholar, and Google were searched to determine the presence of Borreliella and Borrelia spp. in vectors, animals, and humans in countries around the Mediterranean Sea. A total of 3026 were identified and screened and after exclusion of papers that did not fulfill the including criteria, 429 were used. After examination of the available literature, it was revealed that various species associated with LD and RF are prevalent in vectors, animals, and humans in Mediterranean countries and should be monitored in order to effectively manage and prevent potential infections.
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Affiliation(s)
- Myrto Koutantou
- Diagnostic Department and Public Health Laboratories, Hellenic Pasteur Institute, 11521 Athens, Greece
| | | | - Emmanouil Angelakis
- Diagnostic Department and Public Health Laboratories, Hellenic Pasteur Institute, 11521 Athens, Greece
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2
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Hassall RMJ, Burthe SJ, Schäfer SM, Hartemink N, Purse BV. Using mechanistic models to highlight research priorities for tick-borne zoonotic diseases: Improving our understanding of the ecology and maintenance of Kyasanur Forest Disease in India. PLoS Negl Trop Dis 2023; 17:e0011300. [PMID: 37126514 PMCID: PMC10174626 DOI: 10.1371/journal.pntd.0011300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 05/11/2023] [Accepted: 04/11/2023] [Indexed: 05/02/2023] Open
Abstract
The risk of spillover of zoonotic diseases to humans is changing in response to multiple environmental and societal drivers, particularly in tropical regions where the burden of neglected zoonotic diseases is highest and land use change and forest conversion is occurring most rapidly. Neglected zoonotic diseases can have significant impacts on poor and marginalised populations in low-resource settings but ultimately receive less attention and funding for research and interventions. As such, effective control measures and interventions are often hindered by a limited ecological evidence base, which results in a limited understanding of epidemiologically relevant hosts or vectors and the processes that contribute to the maintenance of pathogens and spillover to humans. Here, we develop a generalisable next generation matrix modelling framework to better understand the transmission processes and hosts that have the greatest contribution to the maintenance of tick-borne diseases with the aim of improving the ecological evidence base and framing future research priorities for tick-borne diseases. Using this model we explore the relative contribution of different host groups and transmission routes to the maintenance of a neglected zoonotic tick-borne disease, Kyasanur Forest Disease Virus (KFD), in multiple habitat types. The results highlight the potential importance of transovarial transmission and small mammals and birds in maintaining this disease. This contradicts previous hypotheses that primates play an important role influencing the distribution of infected ticks. There is also a suggestion that risk could vary across different habitat types but currently more research is needed to evaluate this relationship. In light of these results, we outline the key knowledge gaps for this system and future research priorities that could inform effective interventions and control measures.
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Affiliation(s)
| | - Sarah J. Burthe
- UK Centre for Ecology & Hydrology, Edinburgh, United Kingdom
| | | | - Nienke Hartemink
- Biometris, Wageningen University and Research, Wageningen, The Netherlands
- Quantitative Veterinary Epidemiology Group, Wageningen University and Research, Wageningen, The Netherlands
| | - Bethan V. Purse
- UK Centre for Ecology & Hydrology, Wallingford, United Kingdom
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3
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Browett SS, O'Meara DB, McDevitt AD. Genetic tools in the management of invasive mammals: recent trends and future perspectives. Mamm Rev 2020. [DOI: 10.1111/mam.12189] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Samuel S. Browett
- Ecosystems and Environment Research Centre School of Science, Engineering and Environment University of Salford Salford M5 4WTUK
| | - Denise B. O'Meara
- Molecular Ecology Research Group Eco‐Innovation Research Centre School of Science and Computing Waterford Institute of Technology Waterford Ireland
| | - Allan D. McDevitt
- Ecosystems and Environment Research Centre School of Science, Engineering and Environment University of Salford Salford M5 4WTUK
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4
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Maternal Antibodies Provide Bank Voles with Strain-Specific Protection against Infection by the Lyme Disease Pathogen. Appl Environ Microbiol 2019; 85:AEM.01887-19. [PMID: 31540991 DOI: 10.1128/aem.01887-19] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 09/13/2019] [Indexed: 02/06/2023] Open
Abstract
Multistrain microbial pathogens often induce strain-specific antibody responses in their vertebrate hosts. Mothers can transmit antibodies to their offspring, which can provide short-term, strain-specific protection against infection. Few experimental studies have investigated this phenomenon for multiple strains of zoonotic pathogens occurring in wildlife reservoir hosts. The tick-borne bacterium Borrelia afzelii causes Lyme disease in Europe and consists of multiple strains that cycle between the tick vector (Ixodes ricinus) and vertebrate hosts, such as the bank vole (Myodes glareolus). We used a controlled experiment to show that female bank voles infected with B. afzelii via tick bite transmit protective antibodies to their offspring. To test the specificity of protection, the offspring were challenged using a natural tick bite challenge with either the maternal strain to which the mothers had been exposed or a different strain. The maternal antibodies protected the offspring against a homologous infectious challenge but not against a heterologous infectious challenge. The offspring from the uninfected control mothers were equally susceptible to both strains. Borrelia outer surface protein C (OspC) is an antigen that is known to induce strain-specific immunity. Maternal antibodies in the offspring reacted more strongly with homologous than with heterologous recombinant OspC, but other antigens may also mediate strain-specific immunity. Our study shows that maternal antibodies provide strain-specific protection against B. afzelii in an ecologically important rodent reservoir host. The transmission of maternal antibodies may have important consequences for the epidemiology of multistrain pathogens in nature.IMPORTANCE Many microbial pathogen populations consist of multiple strains that induce strain-specific antibody responses in their vertebrate hosts. Females can transmit these antibodies to their offspring, thereby providing them with short-term strain-specific protection against microbial pathogens. We investigated this phenomenon using multiple strains of the tick-borne microbial pathogen Borrelia afzelii and its natural rodent reservoir host, the bank vole, as a model system. We found that female bank voles infected with B. afzelii transmitted to their offspring maternal antibodies that provided highly efficient but strain-specific protection against a natural tick bite challenge. The transgenerational transfer of antibodies could be a mechanism that maintains the high strain diversity of this tick-borne pathogen in nature.
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5
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Gomez-Chamorro A, Battilotti F, Cayol C, Mappes T, Koskela E, Boulanger N, Genné D, Sarr A, Voordouw MJ. Susceptibility to infection with Borrelia afzelii and TLR2 polymorphism in a wild reservoir host. Sci Rep 2019; 9:6711. [PMID: 31040326 PMCID: PMC6491475 DOI: 10.1038/s41598-019-43160-3] [Citation(s) in RCA: 9] [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: 02/26/2018] [Accepted: 04/17/2019] [Indexed: 12/14/2022] Open
Abstract
The study of polymorphic immune genes in host populations is critical for understanding genetic variation in susceptibility to pathogens. Controlled infection experiments are necessary to separate variation in the probability of exposure from genetic variation in susceptibility to infection, but such experiments are rare for wild vertebrate reservoir hosts and their zoonotic pathogens. The bank vole (Myodes glareolus) is an important reservoir host of Borrelia afzelii, a tick-borne spirochete that causes Lyme disease. Bank vole populations are polymorphic for Toll-like receptor 2 (TLR2), an innate immune receptor that recognizes bacterial lipoproteins. To test whether the TLR2 polymorphism influences variation in the susceptibility to infection with B. afzelii, we challenged pathogen-free, lab-born individuals of known TLR2 genotype with B. afzelii-infected ticks. We measured the spirochete load in tissues of the bank voles. The susceptibility to infection with B. afzelii following an infected tick bite was very high (95%) and did not differ between TLR2 genotypes. The TLR2 polymorphism also had no effect on the spirochete abundance in the tissues of the bank voles. Under the laboratory conditions of our study, we did not find that the TLR2 polymorphism in bank voles influenced variation in the susceptibility to B. afzelii infection.
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Affiliation(s)
| | | | - Claire Cayol
- Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland
| | - Tapio Mappes
- Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland
| | - Esa Koskela
- Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland
| | - Nathalie Boulanger
- Facultés de Médecine et de Pharmacie, Université de Strasbourg, Strasbourg, France
| | - Dolores Genné
- Institut de Biologie, Université de Neuchâtel, Neuchâtel, Switzerland
| | - Anouk Sarr
- Institut de Biologie, Université de Neuchâtel, Neuchâtel, Switzerland
| | - Maarten Jeroen Voordouw
- Institut de Biologie, Université de Neuchâtel, Neuchâtel, Switzerland.
- Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada.
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6
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Coipan CE, van Duijvendijk GLA, Hofmeester TR, Takumi K, Sprong H. The genetic diversity of Borrelia afzelii is not maintained by the diversity of the rodent hosts. Parasit Vectors 2018; 11:454. [PMID: 30081938 PMCID: PMC6090804 DOI: 10.1186/s13071-018-3006-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 07/09/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Small mammals are essential in the enzootic cycle of many tick-borne pathogens (TBP). To understand their contribution to the genetic diversity of Borrelia afzelii, the most prevalent TBP in questing Ixodes ricinus, we compared the genetic variants of B. afzelii at three distinct genetic loci. We chose two plasmid loci, dbpA and ospC, and a chromosomal one, IGS. RESULTS While the larvae that fed on shrews (Sorex sp.) tested negative for B. afzelii, those fed on bank voles (Myodes glareolus) and wood mice (Apodemus sylvaticus) showed high infection prevalences of 0.13 and 0.27, respectively. Despite the high genetic diversity within B. afzelii, there was no difference between wood mice and bank voles in the number and types of B. afzelii haplotypes they transmit. CONCLUSIONS The genetic diversity in B. afzelii cannot be explained by separate enzootic cycles in wood mice and bank voles.
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Affiliation(s)
- Claudia E Coipan
- Laboratory of Entomology, Wageningen University, Wageningen, The Netherlands. .,Centre for Epidemiology and Surveillance of Infectious Diseases, National Institute for Public Health and Environment (RIVM), Bilthoven, The Netherlands.
| | - Gilian L A van Duijvendijk
- Laboratory of Entomology, Wageningen University, Wageningen, The Netherlands.,Applied Biology, HAS University of Applied Sciences, 's Hertogenbosch, The Netherlands
| | - Tim R Hofmeester
- Resource Ecology Group, Wageningen University, Wageningen, The Netherlands.,Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Katsuhisa Takumi
- Laboratory for Zoonoses and Environmental Microbiology, National Institute for Public Health and Environment (RIVM), Bilthoven, The Netherlands
| | - Hein Sprong
- Laboratory of Entomology, Wageningen University, Wageningen, The Netherlands.,Laboratory for Zoonoses and Environmental Microbiology, National Institute for Public Health and Environment (RIVM), Bilthoven, The Netherlands
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Marchant A, Le Coupanec A, Joly C, Perthame E, Sertour N, Garnier M, Godard V, Ferquel E, Choumet V. Infection of Ixodes ricinus by Borrelia burgdorferi sensu lato in peri-urban forests of France. PLoS One 2017; 12:e0183543. [PMID: 28846709 PMCID: PMC5573218 DOI: 10.1371/journal.pone.0183543] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Accepted: 08/07/2017] [Indexed: 12/21/2022] Open
Abstract
Lyme borreliosis is the most common tick-borne disease in the northern hemisphere. In Europe, it is transmitted by Ixodes ticks that carry bacteria belonging to the Borrelia burgdorferi sensu lato complex. The objective of this work was to explore eco-epidemiological factors of Lyme borreliosis in peri-urban forests of France (Sénart, Notre-Dame and Rambouillet). We investigated whether the introduction of Tamias sibiricus in Sénart could alter the density of infected ticks. Moreover, the density and tick infection were investigated according to the tree species found in various patches of Sénart forest. For this purpose, ticks were sampled during 3 years. In the Sénart forest, the density of nymph and adult ticks showed no significant difference between 2008, 2009 and 2011. The nymph density varied significantly as a function of the month of collection. Regarding the nymphs, a higher rate of infection and infected density were found in 2009. Plots with chipmunks (C) presented a lower density of both nymphs and adult ticks than plots without chipmunks (NC) did. A higher rate of infection of nymphs with Borrelia was seen in C plots. The prevalence of the various species of Borrelia was also found to vary between C and NC plots with the year of the collect. The presence of chestnut trees positively influenced the density of both nymphs and adults. The infected nymph density showed a significant difference depending on the peri-urban forest studied, Sénart being higher than Rambouillet. The prevalence of Borrelia species also differed between the various forests studied. Concerning the putative role that Tamias sibiricus may play in the transmission of Borrelia, our results suggest that its presence is correlated with a higher rate of infection of questing ticks by Borrelia genospecies and if its population increases, it could play a significant role in the risk of transmission of Lyme borreliosis.
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Affiliation(s)
- Axelle Marchant
- Centre National de Référence des Borrelia, Institut Pasteur, Paris, France
| | - Alain Le Coupanec
- Centre National de Référence des Borrelia, Institut Pasteur, Paris, France
| | - Claire Joly
- Centre National de Référence des Borrelia, Institut Pasteur, Paris, France
| | - Emeline Perthame
- Institut Pasteur – Bioinformatics and Biostatistics Hub – C3BI, USR 3756 IP CNRS –Bioinformatique et Biostatistique, Paris, France
| | - Natacha Sertour
- Centre National de Référence des Borrelia, Institut Pasteur, Paris, France
| | - Martine Garnier
- Centre National de Référence des Borrelia, Institut Pasteur, Paris, France
| | - Vincent Godard
- CNRS-UMR7533/LADYSS, Université de Paris 8 - Saint-Denis, France
| | - Elisabeth Ferquel
- Centre National de Référence des Borrelia, Institut Pasteur, Paris, France
| | - Valerie Choumet
- Centre National de Référence des Borrelia, Institut Pasteur, Paris, France
- Unité Environnement et Risques Infectieux, Institut Pasteur, Paris, France
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8
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Loh SM, Gillett A, Ryan U, Irwin P, Oskam C. Molecular characterization of 'Candidatus Borrelia tachyglossi' (family Spirochaetaceae) in echidna ticks, Bothriocroton concolor. Int J Syst Evol Microbiol 2017; 67:1075-1080. [PMID: 28475032 PMCID: PMC5817193 DOI: 10.1099/ijsem.0.001929] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Recently, a novel species of the genus Borreliawas identified in Bothriocroton concolor and Ixodes holocyclus ticks from echidnas. Analyses of 16S rRNA and flaB genes identified three closely related genotypes of this bacterium (Borrelia sp. Aus A-C) that were unique and distinct from previously described borreliae. Phylogenetic analyses of flaB (763 bp), groEL (1537 bp), gyrB (1702 bp) and glpQ (874 bp) gene sequences and concatenated sequences (3585 bp) of three gene loci (16S rRNA, flaB and gyrB) were consistent with previous findings and confirm that this novel species of the genus Borrelia is more closely related to, yet distinct from, the Reptile-associated (REP) and Relapsing Fever (RF) groups. At the flaB locus, genotypes A, B and C shared the highest percentage sequence similarities (87.9, 88 and 87.9 %, respectively) with B.orrelia turcica (REP), whereas at the groEL and gyrB loci, these genotypes were most similar (88.2–89.4 %) to B.orrelia hermsii (RF). At the glpQ locus, genotypes A and B were most similar (85.7 and 85.4 % respectively) to Borrelia sp. Tortoise14H1 (REP). The presence of the glpQ gene, which is absent in the Lyme Borreliosis group spirochaetes, further emphasises that the novel species of the genus Borrelia characterized in the present study does not belong to this group. Phylogenetic analyses at multiple loci produced consistent topographies revealing the monophyletic grouping of this bacterium, therefore providing strong support for its species status. We propose the name ‘CandidatusBorrelia tachyglossi’, and hypothesize that this species of the genus Borrelia may be endemic to Australia. The pathogenic potential of this bacterium is not yet known.
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Affiliation(s)
- Siew-May Loh
- Vector and Water-Borne Pathogen Research Group, School of Veterinary and Life Sciences, Murdoch University, Perth, Western Australia, Australia
| | - Amber Gillett
- Australia Zoo Wildlife Hospital, Beerwah, Queensland, Australia
| | - Una Ryan
- Vector and Water-Borne Pathogen Research Group, School of Veterinary and Life Sciences, Murdoch University, Perth, Western Australia, Australia
| | - Peter Irwin
- Vector and Water-Borne Pathogen Research Group, School of Veterinary and Life Sciences, Murdoch University, Perth, Western Australia, Australia
| | - Charlotte Oskam
- Vector and Water-Borne Pathogen Research Group, School of Veterinary and Life Sciences, Murdoch University, Perth, Western Australia, Australia
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9
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Chastagner A, Pion A, Verheyden H, Lourtet B, Cargnelutti B, Picot D, Poux V, Bard É, Plantard O, McCoy KD, Leblond A, Vourc'h G, Bailly X. Host specificity, pathogen exposure, and superinfections impact the distribution of Anaplasma phagocytophilum genotypes in ticks, roe deer, and livestock in a fragmented agricultural landscape. INFECTION GENETICS AND EVOLUTION 2017; 55:31-44. [PMID: 28807858 DOI: 10.1016/j.meegid.2017.08.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 08/08/2017] [Accepted: 08/10/2017] [Indexed: 10/19/2022]
Abstract
Anaplasma phagocytophilum is a bacterial pathogen mainly transmitted by Ixodes ricinus ticks in Europe. It infects wild mammals, livestock, and, occasionally, humans. Roe deer are considered to be the major reservoir, but the genotypes they carry differ from those that are found in livestock and humans. Here, we investigated whether roe deer were the main source of the A. phagocytophilum genotypes circulating in questing I. ricinus nymphs in a fragmented agricultural landscape in France. First, we assessed pathogen prevalence in 1837 I. ricinus nymphs (sampled along georeferenced transects) and 79 roe deer. Prevalence was dramatically different between ticks and roe deer: 1.9% versus 76%, respectively. Second, using high-throughput amplicon sequencing, we characterized the diversity of the A. phagocytophilum genotypes found in 22 infected ticks and 60 infected roe deer; the aim was to determine the frequency of co-infections. Only 22.7% of infected ticks carried genotypes associated with roe deer. This finding fits with others suggesting that cattle density is the major factor explaining infected tick density. To explore epidemiological scenarios capable of explaining these patterns, we constructed compartmental models that focused on how A. phagocytophilum exposure and infection dynamics affected pathogen prevalence in roe deer. At the exposure levels predicted by the results of this study and the literature, the high prevalence in roe deer was only seen in the model in which superinfections could occur during all infection phases and when the probability of infection post exposure was above 0.43. We then interpreted these results from the perspective of livestock and human health.
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Affiliation(s)
- Amélie Chastagner
- EPIA, UMR 0346, Epidémiologie des maladies Animales et zoonotiques, INRA, VetAgroSup, Route de Theix, F-63122 Saint Genes Champanelle, France; Evolutionary Ecology Group, Department of Biology, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium
| | - Angélique Pion
- EPIA, UMR 0346, Epidémiologie des maladies Animales et zoonotiques, INRA, VetAgroSup, Route de Theix, F-63122 Saint Genes Champanelle, France
| | - Hélène Verheyden
- CEFS, UR0035, Comportement et Ecologie de la Faune Sauvage, Université de Toulouse, INRA, 24 chemin de Borde-Rouge, F-31326 Castanet-Tolosan, France
| | - Bruno Lourtet
- CEFS, UR0035, Comportement et Ecologie de la Faune Sauvage, Université de Toulouse, INRA, 24 chemin de Borde-Rouge, F-31326 Castanet-Tolosan, France
| | - Bruno Cargnelutti
- CEFS, UR0035, Comportement et Ecologie de la Faune Sauvage, Université de Toulouse, INRA, 24 chemin de Borde-Rouge, F-31326 Castanet-Tolosan, France
| | - Denis Picot
- CEFS, UR0035, Comportement et Ecologie de la Faune Sauvage, Université de Toulouse, INRA, 24 chemin de Borde-Rouge, F-31326 Castanet-Tolosan, France
| | - Valérie Poux
- EPIA, UMR 0346, Epidémiologie des maladies Animales et zoonotiques, INRA, VetAgroSup, Route de Theix, F-63122 Saint Genes Champanelle, France
| | - Émilie Bard
- EPIA, UMR 0346, Epidémiologie des maladies Animales et zoonotiques, INRA, VetAgroSup, Route de Theix, F-63122 Saint Genes Champanelle, France
| | - Olivier Plantard
- BIOEPAR, UMR 1300, Biologie, Epidemiologie et Analyse de Risque, INRA, UNAM Université, Oniris, Ecole Nationale Vétérinaire, Agroalimentaire et de l'Alimentation Nantes-Atlantique, Atlanpôle, la Chantrerie, F-44307, Nantes, France
| | - Karen D McCoy
- MIVEGEC (UMR 5290), Maladie Infectieuses et Vecteurs: Ecologie, Génétique Evolution et Contrôle, Centre National de la Recherche Scientifique, Université de Montpellier, Institut de Recherche pour le Développement (UR224), 911 Avenue d'Agropolis, BP 64501, F-34394 Cedex 5, Montpellier, France
| | - Agnes Leblond
- EPIA, UMR 0346, Epidémiologie des maladies Animales et zoonotiques, INRA, VetAgroSup, Route de Theix, F-63122 Saint Genes Champanelle, France
| | - Gwenaël Vourc'h
- EPIA, UMR 0346, Epidémiologie des maladies Animales et zoonotiques, INRA, VetAgroSup, Route de Theix, F-63122 Saint Genes Champanelle, France
| | - Xavier Bailly
- EPIA, UMR 0346, Epidémiologie des maladies Animales et zoonotiques, INRA, VetAgroSup, Route de Theix, F-63122 Saint Genes Champanelle, France.
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10
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Durand J, Jacquet M, Rais O, Gern L, Voordouw MJ. Fitness estimates from experimental infections predict the long-term strain structure of a vector-borne pathogen in the field. Sci Rep 2017; 7:1851. [PMID: 28500292 PMCID: PMC5431797 DOI: 10.1038/s41598-017-01821-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 04/04/2017] [Indexed: 11/18/2022] Open
Abstract
The populations of many pathogen species consist of a collection of common and rare strains but the factors underlying this strain-specific variation in frequency are often unknown. Understanding frequency variation among strains is particularly challenging for vector-borne pathogens where the strain-specific fitness depends on the performance in both the vertebrate host and the arthropod vector. Two sympatric multiple-strain tick-borne pathogens, Borrelia afzelii and B. garinii, that use the same tick vector, Ixodes ricinus, but different vertebrate hosts were studied. 454-sequencing of the polymorphic ospC gene was used to characterize the community of Borrelia strains in a local population of I. ricinus ticks over a period of 11 years. Estimates of the reproduction number (R0), a measure of fitness, were obtained for six strains of B. afzelii from a previous laboratory study. There was substantial variation in prevalence among strains and some strains were consistently common whereas other strains were consistently rare. In B. afzelii, the strain-specific estimates of R0 in laboratory mice explained over 70% of the variation in the prevalences of the strains in our local population of ticks. Our study shows that laboratory estimates of fitness can predict the community structure of multiple-strain pathogens in the field.
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Affiliation(s)
- Jonas Durand
- Laboratory of Ecology and Evolution of Parasites, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Maxime Jacquet
- Laboratory of Ecology and Evolution of Parasites, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Olivier Rais
- Laboratory of Eco-Epidemiology of Parasites, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Lise Gern
- Laboratory of Eco-Epidemiology of Parasites, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Maarten J Voordouw
- Laboratory of Ecology and Evolution of Parasites, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland.
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11
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Obiegala A, Król N, Oltersdorf C, Nader J, Pfeffer M. The enzootic life-cycle of Borrelia burgdorferi (sensu lato) and tick-borne rickettsiae: an epidemiological study on wild-living small mammals and their ticks from Saxony, Germany. Parasit Vectors 2017; 10:115. [PMID: 28285593 PMCID: PMC5346851 DOI: 10.1186/s13071-017-2053-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 02/22/2017] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Borrelia burgdorferi (sensu lato) and rickettsiae of the spotted fever group are zoonotic tick-borne pathogens. While small mammals are confirmed reservoirs for certain Borrelia spp., little is known about the reservoirs for tick-borne rickettsiae. Between 2012 and 2014, ticks were collected from the vegetation and small mammals which were trapped in Saxony, Germany. DNA extracted from ticks and the small mammals' skin was analyzed for the presence of Rickettsia spp. and B. burgdorferi (s.l.) by qPCR targeting the gltA and p41 genes, respectively. Partial sequencing of the rickettsial ompB gene and an MLST of B. burgdorferi (s.l.) were conducted for species determination. RESULTS In total, 673 small mammals belonging to eight species (Apodemus agrarius, n = 7; A. flavicollis, n = 214; Microtus arvalis, n = 8; Microtus agrestis, n = 1; Mustela nivalis, n = 2; Myodes glareolus, n = 435; Sorex araneus, n = 5; and Talpa europaea, n = 1) were collected and examined. In total, 916 questing ticks belonging to three species (Ixodes ricinus, n = 741; Dermacentor reticulatus, n = 174; and I. trianguliceps, n = 1) were collected. Of these, 474 ticks were further investigated. The prevalence for Rickettsia spp. and B. burgdorferi (s.l.) in the investigated small mammals was 25.3 and 31.2%, respectively. The chance of encountering Rickettsia spp. in M. glareolus was seven times higher for specimens infested with D. reticulatus than for those which were free of D. reticulatus (OR: 7.0; 95% CI: 3.3-14.7; P < 0.001). In total, 11.4% of questing I. ricinus and 70.5% of D. reticulatus were positive for Rickettsia spp. DNA of B. burgdorferi (s.l.) was detected only in I. ricinus (5.5%). Sequence analysis revealed 9 R. helvetica, 5 R. raoultii, and 1 R. felis obtained from 15 small mammal samples. CONCLUSION Small mammals may serve as reservoirs for Rickettsia spp. and B. burgdorferi (s.l.). While the prevalence for Rickettsia spp. in M. glareolus is most likely depending on the abundance of attached D. reticulatus, the prevalence for B. burgdorferi (s.l.) in small mammals is independent of tick abundance. Dermacentor reticulatus may be the main vector of certain Rickettsia spp. but not for Borrelia spp.
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Affiliation(s)
- Anna Obiegala
- Institute of Animal Hygiene and Veterinary Public Health, University of Leipzig, An den Tierkliniken 1, 04103 Leipzig, Germany
| | - Nina Król
- Institute of Animal Hygiene and Veterinary Public Health, University of Leipzig, An den Tierkliniken 1, 04103 Leipzig, Germany
- Department of Microbial Ecology and Environmental Protection, Institute of Genetics and Microbiology, University of Wrocław, Przybyszewskiego 63/77, 51-148, Wrocław, Poland
| | - Carolin Oltersdorf
- Institute of Animal Hygiene and Veterinary Public Health, University of Leipzig, An den Tierkliniken 1, 04103 Leipzig, Germany
| | - Julian Nader
- Institute of Animal Hygiene and Veterinary Public Health, University of Leipzig, An den Tierkliniken 1, 04103 Leipzig, Germany
| | - Martin Pfeffer
- Institute of Animal Hygiene and Veterinary Public Health, University of Leipzig, An den Tierkliniken 1, 04103 Leipzig, Germany
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Durand J, Herrmann C, Genné D, Sarr A, Gern L, Voordouw MJ. Multistrain Infections with Lyme Borreliosis Pathogens in the Tick Vector. Appl Environ Microbiol 2017; 83:e02552-16. [PMID: 27836839 PMCID: PMC5244308 DOI: 10.1128/aem.02552-16] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 11/08/2016] [Indexed: 12/16/2022] Open
Abstract
Mixed or multiple-strain infections are common in vector-borne diseases and have important implications for the epidemiology of these pathogens. Previous studies have mainly focused on interactions between pathogen strains in the vertebrate host, but little is known about what happens in the arthropod vector. Borrelia afzelii and Borrelia garinii are two species of spirochete bacteria that cause Lyme borreliosis in Europe and that share a tick vector, Ixodes ricinus Each of these two tick-borne pathogens consists of multiple strains that are often differentiated using the highly polymorphic ospC gene. For each Borrelia species, we studied the frequencies and abundances of the ospC strains in a wild population of I. ricinus ticks that had been sampled from the same field site over a period of 3 years. We used quantitative PCR (qPCR) and 454 sequencing to estimate the spirochete load and the strain diversity within each tick. For B. afzelii, there was a negative relationship between the two most common ospC strains, suggesting the presence of competitive interactions in the vertebrate host and possibly the tick vector. The flat relationship between total spirochete abundance and strain richness in the nymphal tick indicates that the mean abundance per strain decreases as the number of strains in the tick increases. Strains with the highest spirochete load in the nymphal tick were the most common strains in the tick population. The spirochete abundance in the nymphal tick appears to be an important life history trait that explains why some strains are more common than others in nature. IMPORTANCE Lyme borreliosis is the most common vector-borne disease in the Northern Hemisphere and is caused by spirochete bacteria that belong to the Borrelia burgdorferi sensu lato species complex. These tick-borne pathogens are transmitted among vertebrate hosts by hard ticks of the genus Ixodes Each Borrelia species can be further subdivided into genetically distinct strains. Multiple-strain infections are common in both the vertebrate host and the tick vector and can result in competitive interactions. To date, few studies on multiple-strain vector-borne pathogens have investigated patterns of cooccurrence and abundance in the arthropod vector. We demonstrate that the abundance of a given strain in the tick vector is negatively affected by the presence of coinfecting strains. In addition, our study suggests that the spirochete abundance in the tick is an important life history trait that can explain why some strains are more common in nature than others.
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Affiliation(s)
- Jonas Durand
- Laboratory of Ecology and Evolution of Parasites, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Coralie Herrmann
- Laboratory of Eco-Epidemiology of Parasites, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Dolores Genné
- Laboratory of Ecology and Evolution of Parasites, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Anouk Sarr
- Laboratory of Ecology and Evolution of Parasites, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Lise Gern
- Laboratory of Eco-Epidemiology of Parasites, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Maarten J Voordouw
- Laboratory of Ecology and Evolution of Parasites, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
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Jacquet M, Margos G, Fingerle V, Voordouw MJ. Comparison of the lifetime host-to-tick transmission between two strains of the Lyme disease pathogen Borrelia afzelii. Parasit Vectors 2016; 9:645. [PMID: 27986081 PMCID: PMC5162089 DOI: 10.1186/s13071-016-1929-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 12/04/2016] [Indexed: 11/10/2022] Open
Abstract
Background Transmission from the vertebrate host to the arthropod vector is a critical step in the life-cycle of any vector-borne pathogen. How the probability of host-to-vector transmission changes over the duration of the infection is an important predictor of pathogen fitness. The Lyme disease pathogen Borrelia afzelii is transmitted by Ixodes ricinus ticks and establishes a chronic infection inside rodent reservoir hosts. The present study compares the temporal pattern of host-to-tick transmission between two strains of B. afzelii. Methods Laboratory mice were experimentally infected via tick bite with one of two strains of B. afzelii: A3 and A10. Mice were repeatedly infested with pathogen-free larval Ixodes ricinus ticks over a period of 4 months. Engorged larval ticks moulted into nymphal ticks that were tested for infection with B. afzelii using qPCR. The proportion of infected nymphs was used to characterize the pattern of host-to-tick transmission over time. Results Both strains of B. afzelii followed a similar pattern of host-to-tick transmission. Transmission decreased from the acute to the chronic phase of the infection by 16.1 and 29.3% for strains A3 and A10, respectively. Comparison between strains found no evidence of a trade-off in transmission between the acute and chronic phase of infection. Strain A10 had higher lifetime fitness and established a consistently higher spirochete load in nymphal ticks than strain A3. Conclusion Quantifying the relationship between host-to-vector transmission and the age of infection in the host is critical for estimating the lifetime fitness of vector-borne pathogens. Electronic supplementary material The online version of this article (doi:10.1186/s13071-016-1929-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Maxime Jacquet
- Laboratory of Ecology and Evolution of Parasites, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Gabriele Margos
- National Reference Centre for Borrelia, Munich, Oberschleissheim, Germany.,Bavarian Health and Food Safety Authority, Munich, Oberschleissheim, Germany
| | - Volker Fingerle
- National Reference Centre for Borrelia, Munich, Oberschleissheim, Germany.,Bavarian Health and Food Safety Authority, Munich, Oberschleissheim, Germany
| | - Maarten J Voordouw
- Laboratory of Ecology and Evolution of Parasites, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland.
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Multiple independent transmission cycles of a tick-borne pathogen within a local host community. Sci Rep 2016; 6:31273. [PMID: 27498685 PMCID: PMC4976386 DOI: 10.1038/srep31273] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 07/15/2016] [Indexed: 01/09/2023] Open
Abstract
Many pathogens are maintained by multiple host species and involve multiple strains with potentially different phenotypic characteristics. Disentangling transmission patterns in such systems is often challenging, yet investigating how different host species contribute to transmission is crucial to properly assess and manage disease risk. We aim to reveal transmission cycles of bacteria within the Borrelia burgdorferi species complex, which include Lyme disease agents. We characterized Borrelia genotypes found in 488 infected Ixodes ricinus nymphs collected in the Sénart Forest located near Paris (France). These genotypes were compared to those observed in three sympatric species of small mammals and network analyses reveal four independent transmission cycles. Statistical modelling shows that two cycles involving chipmunks, an introduced species, and non-sampled host species such as birds, are responsible for the majority of tick infections. In contrast, the cycle involving native bank voles only accounts for a small proportion of infected ticks. Genotypes associated with the two primary transmission cycles were isolated from Lyme disease patients, confirming the epidemiological threat posed by these strains. Our work demonstrates that combining high-throughput sequence typing with networks tools and statistical modeling is a promising approach for characterizing transmission cycles of multi-host pathogens in complex ecological settings.
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Esteve-Gassent MD, Castro-Arellano I, Feria-Arroyo TP, Patino R, Li AY, Medina RF, Pérez de León AA, Rodríguez-Vivas RI. TRANSLATING ECOLOGY, PHYSIOLOGY, BIOCHEMISTRY, AND POPULATION GENETICS RESEARCH TO MEET THE CHALLENGE OF TICK AND TICK-BORNE DISEASES IN NORTH AMERICA. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2016; 92:38-64. [PMID: 27062414 PMCID: PMC4844827 DOI: 10.1002/arch.21327] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 02/20/2016] [Indexed: 06/05/2023]
Abstract
Emerging and re-emerging tick-borne diseases threaten public health and the wellbeing of domestic animals and wildlife globally. The adoption of an evolutionary ecology framework aimed to diminish the impact of tick-borne diseases needs to be part of strategies to protect human and animal populations. We present a review of current knowledge on the adaptation of ticks to their environment, and the impact that global change could have on their geographic distribution in North America. Environmental pressures will affect tick population genetics by selecting genotypes able to withstand new and changing environments and by altering the connectivity and isolation of several tick populations. Research in these areas is particularly lacking in the southern United States and most of Mexico with knowledge gaps on the ecology of these diseases, including a void in the identity of reservoir hosts for several tick-borne pathogens. Additionally, the way in which anthropogenic changes to landscapes may influence tick-borne disease ecology remains to be fully understood. Enhanced knowledge in these areas is needed in order to implement effective and sustainable integrated tick management strategies. We propose to refocus ecology studies with emphasis on metacommunity-based approaches to enable a holistic perspective addressing whole pathogen and host assemblages. Network analyses could be used to develop mechanistic models involving multihost-pathogen communities. An increase in our understanding of the ecology of tick-borne diseases across their geographic distribution will aid in the design of effective area-wide tick control strategies aimed to diminish the burden of pathogens transmitted by ticks.
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Affiliation(s)
- Maria D. Esteve-Gassent
- Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical sciences, Texas A&M University, College Station, TX-77843, USA
| | - Ivan Castro-Arellano
- Department of Biology, College of Science and Engineering, Texas State University, San Marcos, TX-78666, USA
| | - Teresa P. Feria-Arroyo
- Department of Biology, The University of Texas Rio Grande Valley, Edinburg, TX-78539, USA
| | - Ramiro Patino
- Department of Biology, The University of Texas Rio Grande Valley, Edinburg, TX-78539, USA
| | - Andrew Y. Li
- USDA-ARS Invasive Insect Biocontrol and Behavior Laboratory, Beltsville, Maryland 20705, USA
| | - Raul F. Medina
- Department of Entomology, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX-77843, USA
| | - Adalberto A. Pérez de León
- USDA-ARS Knipling-Bushland U.S. Livestock Insects Research Laboratory, and Veterinary Pest Genomics Center, Kerrville, TX-78028, USA
| | - Roger Iván Rodríguez-Vivas
- Campus de Ciencias Biológicas y Agropecuarias. Facultad de Medicina Veterinaria y Zootecnia. Km 15.5 carretera Mérida-Xmatkuil. Yucatán, México
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16
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Kuczyński L, Rector BG, Kiedrowicz A, Lewandowski M, Szydło W, Skoracka A. Thermal Niches of Two Invasive Genotypes of the Wheat Curl Mite Aceria tosichella: Congruence between Physiological and Geographical Distribution Data. PLoS One 2016; 11:e0154600. [PMID: 27123590 PMCID: PMC4849750 DOI: 10.1371/journal.pone.0154600] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 04/16/2016] [Indexed: 11/19/2022] Open
Abstract
The wheat curl mite (WCM), Aceria tosichella Keifer, is a major pest of cereals worldwide. It is also a complex of well-defined genetic lineages with divergent physiological traits, which has not been accounted for in applied contexts. The aims of the study were to model the thermal niches of the two most pestiferous WCM lineages, designated MT-1 and MT-8, and to assess the extent to which temperature determines the distribution of these lineages. WCM population dynamics were modeled based on thermal niche data from March to November on the area of Poland (>311,000 km2). The most suitable regions for population development were predicted and compared to empirical field abundance data. Congruence between modeled parameters and field data for mite presence were observed for both WCM lineages although congruence between modeled thermal suitability and mite field abundance was observed only for MT-8. Thermal niche data for MT-1 and MT-8 provide biological insights and aid monitoring and management of WCM and the plant viruses it vectors. The presented models accurately estimate distributions of WCM and can be incorporated into management strategies for both current and predicted climate scenarios.
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Affiliation(s)
- Lechosław Kuczyński
- Department of Avian Biology and Ecology, Institute of Environmental Biology, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
| | - Brian G. Rector
- United States Department of Agriculture (USDA-ARS), Great Basin Rangelands Research Unit, Reno, United States of America
| | - Agnieszka Kiedrowicz
- Department of Animal Taxonomy and Ecology, Institute of Environmental Biology, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
| | - Mariusz Lewandowski
- Department of Applied Entomology, Faculty of Horticulture, Biotechnology and Landscape Architecture, Warsaw University of Life Sciences–SGGW, Warsaw, Poland
| | - Wiktoria Szydło
- Department of Animal Taxonomy and Ecology, Institute of Environmental Biology, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
| | - Anna Skoracka
- Department of Animal Taxonomy and Ecology, Institute of Environmental Biology, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
- * E-mail:
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Vourc'h G, Abrial D, Bord S, Jacquot M, Masséglia S, Poux V, Pisanu B, Bailly X, Chapuis JL. Mapping human risk of infection with Borrelia burgdorferi sensu lato, the agent of Lyme borreliosis, in a periurban forest in France. Ticks Tick Borne Dis 2016; 7:644-652. [PMID: 26897396 DOI: 10.1016/j.ttbdis.2016.02.008] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 01/22/2016] [Accepted: 02/05/2016] [Indexed: 12/19/2022]
Abstract
Lyme borreliosis is a major zoonosis in Europe, with estimates of over 26,000 cases per year in France alone. The etiological agents are spirochete bacteria that belong to the Borrelia burgdorferi sensu lato (s. l.) complex and are transmitted by hard ticks among a large range of vertebrate hosts. In Europe, the tick Ixodes ricinus is the main vector. In the absence of a vaccine and given the current difficulties to diagnose and treat chronic Lyme syndromes, there is urgent need for prevention. In this context, accurate information on the spatial patterns of risk of exposure to ticks is of prime importance for public health. The objective of our study was to provide a snapshot map of the risk of human infection with B. burgdorferi s. l. pathogens in a periurban forest at a high resolution, and to analyze the factors that contribute to variation in this risk. Field monitoring took place over three weeks in May 2011 in the suburban Sénart forest (3,200ha; southeast of Paris), which receives over 3 million people annually. We sampled ticks over the entire forest area (from 220 forest stands with a total area of 35,200m(2)) and quantified the density of questing nymphs (DON), the prevalence of infection among nymphs (NIP), and the density of infected nymphs (DIN), which is the most important predictor of the human risk of Lyme borreliosis. For each of these response variables, we explored the relative roles of weather (saturation deficit), hosts (abundance indices of ungulates and Tamias sibiricus, an introduced rodent species), vegetation and forest cover, superficial soil composition, and the distance to forest roads. In total, 19,546 questing nymphs were collected and the presence of B. burgdorferi s. l. was tested in 3,903 nymphs by qPCR. The mean DON was 5.6 nymphs per 10m(2) (standard deviation=10.4) with an average NIP of 10.1% (standard deviation=0.11). The highest DIN was 8.9 infected nymphs per 10m(2), with a mean of 0.59 (standard deviation=0.6). Our mapping and modeling revealed a strong heterogeneity of risk within the forest. The highest risk was found in the eastern part of the forest and localized patches in the northwestern part. Lyme borreliosis risk was positively associated with stands of deciduous trees (mainly oaks) and roe deer abundance. Contrary to expectations, DIN actually increased with distance from the point of introduction of T. sibiricus (i.e., DIN was higher in areas with potentially lower abundances of T. sibiricus). Thus, despite the fact that T. sibiricus is an important reservoir host for B. burgdorferi s. l., our study found that other explanatory factors played a more important role in determining the density of infected ticks. Precise mapping of the risk of exposure to Lyme borreliosis in a highly visited forest represents an important tool for targeting prevention and control measures, as well as making the general public and local health officials aware of the risks.
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Affiliation(s)
- G Vourc'h
- INRA, UR0346 Unité d'Epidémiologie Animale, 63122 Saint Genès Champanelle, France.
| | - D Abrial
- INRA, UR0346 Unité d'Epidémiologie Animale, 63122 Saint Genès Champanelle, France
| | - S Bord
- INRA, UR0346 Unité d'Epidémiologie Animale, 63122 Saint Genès Champanelle, France
| | - M Jacquot
- INRA, UR0346 Unité d'Epidémiologie Animale, 63122 Saint Genès Champanelle, France
| | - S Masséglia
- INRA, UR0346 Unité d'Epidémiologie Animale, 63122 Saint Genès Champanelle, France
| | - V Poux
- INRA, UR0346 Unité d'Epidémiologie Animale, 63122 Saint Genès Champanelle, France
| | - B Pisanu
- MNHN, Centre d'Ecologie et des Sciences de la Conservation (UMR7204), Sorbonne Universités, MNHN, CNRS, UPMC, CP51, 61 rue Buffon, 75231 Paris Cedex 05, France
| | - X Bailly
- INRA, UR0346 Unité d'Epidémiologie Animale, 63122 Saint Genès Champanelle, France
| | - J-L Chapuis
- MNHN, Centre d'Ecologie et des Sciences de la Conservation (UMR7204), Sorbonne Universités, MNHN, CNRS, UPMC, CP51, 61 rue Buffon, 75231 Paris Cedex 05, France
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Multi-trophic interactions driving the transmission cycle of Borrelia afzelii between Ixodes ricinus and rodents: a review. Parasit Vectors 2015; 8:643. [PMID: 26684199 PMCID: PMC4684625 DOI: 10.1186/s13071-015-1257-8] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 12/10/2015] [Indexed: 11/22/2022] Open
Abstract
The tick Ixodes ricinus is the main vector of the spirochaete Borrelia burgdorferi sensu lato, the causal agent of Lyme borreliosis, in the western Palearctic. Rodents are the reservoir host of B. afzelii, which can be transmitted to I. ricinus larvae during a blood meal. The infected engorged larvae moult into infected nymphs, which can transmit the spirochaetes to rodents and humans. Interestingly, even though only about 1 % of the larvae develop into a borreliae-infected nymph, the enzootic borreliae lifecycle can persist. The development from larva to infected nymph is a key aspect in this lifecycle, influencing the density of infected nymphs and thereby Lyme borreliosis risk. The density of infected nymphs varies temporally and geographically and is influenced by multi-trophic (tick-host-borreliae) interactions. For example, blood feeding success of ticks and spirochaete transmission success differ between rodent species and host-finding success appears to be affected by a B. afzelii infection in both the rodent and the tick. In this paper, we review the major interactions between I. ricinus, rodents and B. afzelii that influence this development, with the aim to elucidate the critical factors that determine the epidemiological risk of Lyme borreliosis. The effects of the tick, rodent and B. afzelii on larval host finding, larval blood feeding, spirochaete transmission from rodent to larva and development from larva to nymph are discussed. Nymphal host finding, nymphal blood feeding and spirochaete transmission from nymph to rodent are the final steps to complete the enzootic B. afzelii lifecycle and are included in the review. It is concluded that rodent density, rodent infection prevalence, and tick burden are the major factors affecting the development from larva to infected nymph and that these interact with each other. We suggest that the B. afzelii lifecycle is dependent on the aggregation of ticks among rodents, which is manipulated by the pathogen itself. Better understanding of the processes involved in the development and aggregation of ticks results in more precise estimates of the density of infected nymphs, and hence predictions of Lyme borreliosis risk.
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Cross-Immunity and Community Structure of a Multiple-Strain Pathogen in the Tick Vector. Appl Environ Microbiol 2015; 81:7740-52. [PMID: 26319876 DOI: 10.1128/aem.02296-15] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 08/25/2015] [Indexed: 12/11/2022] Open
Abstract
Many vector-borne pathogens consist of multiple strains that circulate in both the vertebrate host and the arthropod vector. Characterization of the community of pathogen strains in the arthropod vector is therefore important for understanding the epidemiology of mixed vector-borne infections. Borrelia afzelii and B. garinii are two species of tick-borne bacteria that cause Lyme disease in humans. These two sympatric pathogens use the same tick, Ixodes ricinus, but are adapted to different classes of vertebrate hosts. Both Borrelia species consist of multiple strains that are classified using the highly polymorphic ospC gene. Vertebrate cross-immunity against the OspC antigen is predicted to structure the community of multiple-strain Borrelia pathogens. Borrelia isolates were cultured from field-collected I. ricinus ticks over a period spanning 11 years. The Borrelia species of each isolate was identified using a reverse line blot (RLB) assay. Deep sequencing was used to characterize the ospC communities of 190 B. afzelii isolates and 193 B. garinii isolates. Infections with multiple ospC strains were common in ticks, but vertebrate cross-immunity did not influence the strain structure in the tick vector. The pattern of genetic variation at the ospC locus suggested that vertebrate cross-immunity exerts strong selection against intermediately divergent ospC alleles. Deep sequencing found that more than 50% of our isolates contained exotic ospC alleles derived from other Borrelia species. Two alternative explanations for these exotic ospC alleles are cryptic coinfections that were not detected by the RLB assay or horizontal transfer of the ospC gene between Borrelia species.
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An Invasive Mammal (the Gray Squirrel, Sciurus carolinensis) Commonly Hosts Diverse and Atypical Genotypes of the Zoonotic Pathogen Borrelia burgdorferi Sensu Lato. Appl Environ Microbiol 2015; 81:4236-45. [PMID: 25888168 PMCID: PMC4475893 DOI: 10.1128/aem.00109-15] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 04/03/2015] [Indexed: 11/29/2022] Open
Abstract
Invasive vertebrate species can act as hosts for endemic pathogens and may alter pathogen community composition and dynamics. For the zoonotic pathogen Borrelia burgdorferisensu lato, the agent of Lyme borreliosis, recent work shows invasive rodent species can be of high epidemiological importance and may support host-specific strains. This study examined the role of gray squirrels (Sciurus carolinensis) (n = 679), an invasive species in the United Kingdom, as B. burgdorferi sensu lato hosts. We found that gray squirrels were frequently infested with Ixodes ricinus, the main vector of B. burgdorferi sensu lato in the United Kingdom, and 11.9% were infected with B. burgdorferi sensu lato. All four genospecies that occur in the United Kingdom were detected in gray squirrels, and unexpectedly, the bird-associated genospecies Borrelia garinii was most common. The second most frequent infection was with Borrelia afzelii. Genotyping of B. garinii and B. afzelii produced no evidence for strains associated with gray squirrels. Generalized linear mixed models (GLMM) identified tick infestation and date of capture as significant factors associated with B. burgdorferi sensu lato infection in gray squirrels, with infection elevated in early summer in squirrels infested with ticks. Invasive gray squirrels appear to become infected with locally circulating strains of B. burgdorferi sensu lato, and further studies are required to determine their role in community disease dynamics. Our findings highlight the fact that the role of introduced host species in B. burgdorferi sensu lato epidemiology can be highly variable and thus difficult to predict.
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Bonnet S, Choumet V, Masseglia S, Cote M, Ferquel E, Lilin T, Marsot M, Chapuis JL, Vourc'h G. Infection of Siberian chipmunks (Tamias sibiricus barberi) with Borrelia sp. reveals a low reservoir competence under experimental conditions. Ticks Tick Borne Dis 2015; 6:393-400. [PMID: 25805623 DOI: 10.1016/j.ttbdis.2015.03.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 03/04/2015] [Accepted: 03/05/2015] [Indexed: 01/31/2023]
Abstract
Reservoir competence is a key parameter in understanding the role of host species in the epidemiology of multi-host-especially vector-borne-pathogens. With this aim in view, we studied the reservoir competence of the Siberian chipmunk (Tamias sibiricus barberi) recently introduced into Europe, for the multi-host tick-borne bacteria, Borrelia burgdorferi sl, the agent of Lyme borreliosis. T. sibiricus were experimentally exposed to bites from Ixodes ricinus ticks infected with Borrelia burgdorferi sensu stricto and Borrelia afzelii, with subsequent assessment of bacteremia and antibody responses. Borrelia was detected in chipmunk blood samples, ear biopsies and organ necropsies, and in nymphs used for xenodiagnosis (at one and six months after the initial chipmunk infection) via both serological and molecular methods. In total, eight out of twelve chipmunks showed evidence of infection by Borrelia sp., either by ELISA or PCR. Five chipmunks developed an immune response against the bacteria one month after infection. Borrelia infection in at least one organ was observed in seven animals at 14, 38, 93 or 178 days post-infection. Xenodiagnosis was positive for one chipmunk at 38 days, but no longer at 178 days post-infection. Four chipmunks remained uninfected, despite similar infection pressures to those observed in the field. Taken together, these results suggest that chipmunks can be infected through Borrelia-infected tick bites, and can transmit Borrelia to nymphs, but do not remain persistently infected.
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Affiliation(s)
- Sarah Bonnet
- USC INRA Bartonella-tiques, UMR BIPAR ENVA-ANSES, 94706 Maisons-Alfort, France.
| | - Valérie Choumet
- Institut Pasteur, CNR des Borrelia, 28 rue du Dr Roux, 75724 Paris cedex 15, France.
| | - Sébastien Masseglia
- Unité Epidémiologie Animale (UR INRA 346), Centre de recherche INRA de Clermont-Ferrand/Theix, 63122 Saint Genès Champanelle, France.
| | - Martine Cote
- USC INRA Bartonella-tiques, UMR BIPAR ENVA-ANSES, 94706 Maisons-Alfort, France.
| | - Elisabeth Ferquel
- Institut Pasteur, CNR des Borrelia, 28 rue du Dr Roux, 75724 Paris cedex 15, France.
| | - Thomas Lilin
- Centre de recherches Biomédicales (CRBM), École Nationale Vétérinaire d'Alfort, 7 Avenue du Général de Gaulle, 94700 Maisons-Alfort, France.
| | - Maud Marsot
- Unité Epidémiologie Animale (UR INRA 346), Centre de recherche INRA de Clermont-Ferrand/Theix, 63122 Saint Genès Champanelle, France; Centre d'Ecologie et des Sciences de la Conservation (CESCO UMR7204), Sorbonne Universités, MNHN, CNRS, UPMC, CP51, 55 rue Buffon, 75005 Paris, France.
| | - Jean-Louis Chapuis
- Centre d'Ecologie et des Sciences de la Conservation (CESCO UMR7204), Sorbonne Universités, MNHN, CNRS, UPMC, CP51, 55 rue Buffon, 75005 Paris, France.
| | - Gwenaël Vourc'h
- Unité Epidémiologie Animale (UR INRA 346), Centre de recherche INRA de Clermont-Ferrand/Theix, 63122 Saint Genès Champanelle, France.
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Vaumourin E, Vourc'h G, Telfer S, Lambin X, Salih D, Seitzer U, Morand S, Charbonnel N, Vayssier-Taussat M, Gasqui P. To be or not to be associated: power study of four statistical modeling approaches to identify parasite associations in cross-sectional studies. Front Cell Infect Microbiol 2014; 4:62. [PMID: 24860791 PMCID: PMC4030204 DOI: 10.3389/fcimb.2014.00062] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 04/23/2014] [Indexed: 01/08/2023] Open
Abstract
A growing number of studies are reporting simultaneous infections by parasites in many different hosts. The detection of whether these parasites are significantly associated is important in medicine and epidemiology. Numerous approaches to detect associations are available, but only a few provide statistical tests. Furthermore, they generally test for an overall detection of association and do not identify which parasite is associated with which other one. Here, we developed a new approach, the association screening approach, to detect the overall and the detail of multi-parasite associations. We studied the power of this new approach and of three other known ones (i.e., the generalized chi-square, the network and the multinomial GLM approaches) to identify parasite associations either due to parasite interactions or to confounding factors. We applied these four approaches to detect associations within two populations of multi-infected hosts: (1) rodents infected with Bartonella sp., Babesia microti and Anaplasma phagocytophilum and (2) bovine population infected with Theileria sp. and Babesia sp. We found that the best power is obtained with the screening model and the generalized chi-square test. The differentiation between associations, which are due to confounding factors and parasite interactions was not possible. The screening approach significantly identified associations between Bartonella doshiae and B. microti, and between T. parva, T. mutans, and T. velifera. Thus, the screening approach was relevant to test the overall presence of parasite associations and identify the parasite combinations that are significantly over- or under-represented. Unraveling whether the associations are due to real biological interactions or confounding factors should be further investigated. Nevertheless, in the age of genomics and the advent of new technologies, it is a considerable asset to speed up researches focusing on the mechanisms driving interactions between parasites.
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Affiliation(s)
- Elise Vaumourin
- INRA, UR346 Epidémiologie Animale Saint Genès Champanelle, France ; INRA-Anses-ENVA, USC BIPAR Maisons-Alfort, France
| | - Gwenaël Vourc'h
- INRA, UR346 Epidémiologie Animale Saint Genès Champanelle, France
| | - Sandra Telfer
- School of Biological Sciences, University of Aberdeen Aberdeen, UK
| | - Xavier Lambin
- School of Biological Sciences, University of Aberdeen Aberdeen, UK
| | - Diaeldin Salih
- Department of Ticks and Tick-borne Diseases, Veterinary Research Institute Khartoum, Sudan
| | - Ulrike Seitzer
- Division of Veterinary-Infection Biology and Immunology, Research Center Borstel Borstel, Germany
| | - Serge Morand
- Institut des Sciences de l'Evolution (CNRS /IRD / UM2), University of Montpellier 2 Montpellier, France ; Animal et Gestion Intégrée des Risques, CIRAD Montpellier, France
| | - Nathalie Charbonnel
- INRA, UMR CBGP (INRA / IRD / CIRAD / Montpellier SupAgro) Montpellier, France
| | | | - Patrick Gasqui
- INRA, UR346 Epidémiologie Animale Saint Genès Champanelle, France
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Comparative population genomics of the Borrelia burgdorferi species complex reveals high degree of genetic isolation among species and underscores benefits and constraints to studying intra-specific epidemiological processes. PLoS One 2014; 9:e94384. [PMID: 24721934 PMCID: PMC3993988 DOI: 10.1371/journal.pone.0094384] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 03/13/2014] [Indexed: 11/19/2022] Open
Abstract
Lyme borreliosis, one of the most frequently contracted zoonotic diseases in the Northern Hemisphere, is caused by bacteria belonging to different genetic groups within the Borrelia burgdorferi species complex, which are transmitted by ticks among various wildlife reservoirs, such as small mammals and birds. These features make the Borrelia burgdorferi species complex an attractive biological model that can be used to study the diversification and the epidemiology of endemic bacterial pathogens. We investigated the potential of population genomic approaches to study these processes. Sixty-three strains belonging to three species within the Borrelia burgdorferi complex were isolated from questing ticks in Alsace (France), a region where Lyme disease is highly endemic. We first aimed to characterize the degree of genetic isolation among the species sampled. Phylogenetic and coalescent-based analyses revealed clear delineations: there was a ∼50 fold difference between intra-specific and inter-specific recombination rates. We then investigated whether the population genomic data contained information of epidemiological relevance. In phylogenies inferred using most of the genome, conspecific strains did not cluster in clades. These results raise questions about the relevance of different strategies when investigating pathogen epidemiology. For instance, here, both classical analytic approaches and phylodynamic simulations suggested that population sizes and migration rates were higher in B. garinii populations, which are normally associated with birds, than in B. burgdorferi s.s. populations. The phylogenetic analyses of the infection-related ospC gene and its flanking region provided additional support for this finding. Traces of recombination among the B. burgdorferi s.s. lineages and lineages associated with small mammals were found, suggesting that they shared the same hosts. Altogether, these results provide baseline evidence that can be used to formulate hypotheses regarding the host range of B. burgdorferi lineages based on population genomic data.
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