Phylogenetic analysis of the ornithophilic Borrelia turdi using next generation sequencing.

Borrelia turdi is a genospecies of the B. burgdorferi sensu lato complex that exists in crytic transmission cycles mainly between ornithophilic tick vectors and their avian host.N/

Birds as reservoirs for Borrelia burgdorferi s.l. in Western Europe: circulation of B. turdi and other genospecies in bird-tick cycles in Portugal

Birds as reservoirs for Borrelia burgdorferi s.l. in Western Europe: circulation of B. turdi and other genospecies in bird-tick cycles in Portugal. Norte AC, Ramos JA, Gern L, Núncio MS, Lopes de Carvalho I. SourceInstitute of Marine Research IMAR/CMA, Department of Life Sciences, University of Coimbra, Apartado 3046, 3001-401 Coimbra, Portugal. Center for Vector and Infectious Diseases Research, National Health Institute Doutor Ricardo Jorge, Lisbon, Portugal. Laboratory of Eco-Epidemiology of Parasites, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland. Abstract Birds are important in the ecology of Borrelia burgdorferi sensu lato (s.l.) because they are important hosts for vector tick immature stages and are known reservoirs for some Borrelia genospecies. The aim of our study was to assess the role of common passerine bird species as reservoirs for B. burgdorferi s.l. in Western Europe. We surveyed birds in enzootic areas in Portugal, where no information is available for birds as reservoirs for this aetiologic agent and where B. lusitaniae, for which few reservoirs have been identified, is the dominant genospecies. Twenty-three birds (2.9%), including Turdus merula, T. philomelos, Parus major and Fringilla coelebs harboured infected ticks, but only Turdus sp. harboured infected tick larvae. In one study area, although B. lusitaniae was dominant in questing Ixodes ricinus, no ticks feeding on birds were infected with this genospecies, and B. valaisiana was the dominant genospecies in I. ricinus larvae feeding on birds. In the other area ticks collected from birds were mainly I. frontalis which were infected with B. turdi. Two skin biopsies (4.2%) from two T. merula were positive, one for B. valaisiana and the other for B. turdi. This is the first report for B. turdi in Western Europe. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd. PMID:22882497[PubMed - as supplied by publisher

Blackbirds Turdus merula as competent reservoirs for Borrelia turdi and Borrelia valaisiana in Portugal: evidence from a xenodiagnostic experiment

To confirm that thrushes, such as blackbirds Turdus merula, play a role as reservoir for some Borrelia genospecies, we performed a xenodiagnostic experiment with blackbirds captured in a mixed wood located in Western Portugal where Borrelia turdi, an uncommon genospecies in Europe, was the most prevalent genospecies associated with birds. Two out of five birds harboured B. turdi infected Ixodes frontalis at the time of capture. Four out of five birds transmitted spirochaetes to Ixodes ricinus xenodiagnostic ticks: two birds transmitted Borrelia valaisiana to 25.7% and 10.5% of ticks, and two transmitted B. turdi to 6.4% and 5.4% of ticks. Our results showed that blackbirds transmit B. valaisiana and B. turdi to I. ricinus feeding larvae, acting as reservoir hosts for these genospecies in nature

Diversity and seasonal patterns of ticks parasitizing wild birds in western Portugal

The diversity and abundance of questing ticks and ticks parasitizing birds was assessed during 1 year in two recreational forests in western Portugal, a suburban forest and an enclosed game area. The aim of this study was to assess the distribution and seasonality of tick species and to understand the role of bird species as hosts for ticks. Ixodes ricinus was the most abundant questing tick collected in the enclosed game area, whereas in the suburban forest, only three ticks were collected by blanket dragging. Tick species parasitizing birds included I. ricinus, I. frontalis, I. arboricola, I. acuminatus, Haemaphysalis punctata, Hyalomma marginatum and H. lusitanicum. This is the first record of I. arboricola in Portugal. Tick prevalence and intensity of infestation differed between study areas and was higher in birds from the game area where a large population of deer and wild boar may support tick populations. Ground and shrub dwelling bird species such as Turdus merula, Erithacus rubecula and Sylvia melanocephala were the most heavily parasitized by ticks, but the importance of different bird species as hosts of larvae and nymphs of I. ricinus and I. frontalis differed. Therefore, different bird species may contribute differently for tick population maintenance

Sensitivity of biological samples for Borrelia burgdorferi s.l. infection status assessment in avian hosts

Avian hosts can act as reservoirs for Borrelia burgdorferi sensu lato (s.l.), a bacterial complex that includes the etiologic agents of Lyme borreliosis. It is relevant to evaluate the infection status of the bird species to elucidate their importance as reservoir hosts, because not all contribute equally to the maintenance of Borrelia. There is a lack of a reliable non-invasive technique that allows us to assess the infection status of B. burgdorferi s.l. in wildlife. Thus, the main goal of this study was to evaluate the usefulness of biological samples such as blood and skin biopsies from two avian model species, Turdus merula and Erithacus rubecula, to diagnose B. burgdorferi s.l. infection and give information on their infectivity to ticks. Blood and skin tissues were collected from 16 Erithacus rubecula and 10 Turdus merula captured in Borrelia enzootic areas. These birds were taken into captivity and subjected to xenodiagnoses. DNA was extracted from blood and skin samples and from the fed xenodiagnostic larvae, and analysed for B. burgdorferi s.l. infection by real-time PCR directed to the flaB gene. Sensitivity of these approaches to evaluate host’s infection status will be compared and will help to elucidate B. burgdorferi s.l tropism in the birds’ organism.N/

Tissue infection by Borrelia burgdorferi s.l. in natural and experimental infected avian hosts

Borrelia burgdorferi sl.l. is a bacterial complex that includes pathognic and non-pathogenic genospecies to humans, with diferente reservoir host and vector species associations patterns. The study of the tropismo of B. Burgdorferi sl.l. in the hosts, how the infection is sequestered in diferente organs, and whether i tis maintained in circulation and/or in the host´s skin, is importante to understand pathogenicity and reservoir competency.N/

Bridging of cryptic Borrelia cycles in European songbirds

The principal European vector for Borrelia burgdorferi s.l., the causative agents of Lyme disease, is the host-generalist tick Ixodes ricinus. Almost all terrestrial host-specialist ticks have been supposed not to contribute to the terrestrial Borrelia transmission cycles. Through an experiment with blackbirds, we show successful transmission by the widespread I. frontalis, an abundant bird-specialized tick that infests a broad range of songbirds. In the first phase of the experiment, we obtained Borrelia-infected I. frontalis (infection rate: 19%) and I. ricinus (17%) nymphs by exposing larvae to wild blackbirds that carried several genospecies (Borrelia turdi, B. valaisiana, B. burgdorferi s.s.). In the second phase, pathogen-free blackbirds were exposed to these infected nymphs. Both tick species were able to infect the birds, as indicated by the analysis of xenodiagnostic I. ricinus larvae which provided evidence for both co-feeding and systemic transmission (infection rates: 10%-60%). Ixodes frontalis was shown to transmit B. turdi spirochetes, while I. ricinus transmitted both B. turdi and B. valaisiana. Neither species transmitted B. burgdorferi s.s. European enzootic cycles of Borrelia between songbirds and their ornithophilic ticks do exist, with I. ricinus potentially acting as a bridging vector towards mammals, including man.This research was supported by the Fund for Scientific Research - Flanders Belgium (grant G0.049.10) and the University of Antwerp (KP BOF UA 2015). The molecular work was done under the frame of COST action TD1303 EurNegVec. Dieter Heylen is a postdoctoral fellow at the Fund for Scientific Research - Flanders Belgium (FWO). This study received some financial support from Fundação para a Ciência e a Tecnologia by the strategic program of MARE (MARE - UID/MAR/04292/2013) and the fellowships to Ana Claudia Norte (SFRH/BPD/108197/2015 and SFRH/BPD/62898/2009).info:eu-repo/semantics/publishedVersio

Core genome phylogenetic analysis of the avian associated Borrelia turdi indicates a close relationship to Borrelia garinii

Borrelia burgdorferi sensu lato comprises a species complex of tick-transmitted bacteria that includes the agents of human Lyme borreliosis. Borrelia turdi is a genospecies of this complex that exists in cryptic transmission cycles mainly between ornithophilic tick vectors and their avian hosts. The species has been originally discovered in avian transmission cycles in Asia but has increasingly been found in Europe. Next generation sequencing was used to sequence the genome of B. turdi isolates obtained from ticks feeding on birds in Portugal to better understand the evolution and phylogenetic relationship of this avian and ornithophilic tick-associated genospecies. Here we use draft genomes of these B. turdi isolates for comparative analysis and to determine the taxonomic position within the B. burgdorferi s.l. species complex. The main chromosomes showed a maximum similarity of 93% to other Borrelia species whilst most plasmids had lower similarities. All three isolates had nine or 10 plasmids and, interestingly, one plasmid with a novel partitioning protein; this plasmid was termed lp30. Phylogenetic analysis of multilocus sequence typing housekeeping genes and 113 single copy orthologous genes revealed that the isolates clustered according to their classification as B. turdi. In phylogenies generated from these 113 genes the isolates cluster together with other Eurasian genospecies and form a sister clade to the avian associated B. garinii and the rodent associated B. bavariensis. These findings show that Borrelia species maintained in cryptic ecological cycles need to be included to fully understand the complex ecology and evolutionary history of this bacterial species complex.This work was supported by the Robert-Koch-Institute through funding of the National Reference Center for Borrelia, by Fundação para a Ciência e a Tecnologia - FCT (MARE – UID/MAR/04292/2013; SFRH/BPD/108197/2015) and by the Portuguese National Institute of Health.info:eu-repo/semantics/publishedVersio

Hyalomma ticks infecting tortoises in North Africa and Turkey: distribution, genetic variation and their role as potential vectors

Hyalomma aegyptium is the most common tick species infesting tortoises in the Palearctic. Although larvae and nymphs of these ticks feed on different animal groups, adults of H. aegyptium are highly specific to Testudo. Hyalomma are also carriers of various microorganisms, including pathogens. In this symposium we present the results of two studies on Hyalomma ticks infesting Testudo from North Africa and Turkey. In the first, we analysed the genetic diversity of Hyalomma, and assessed whether the genetic patterns of the ticks matched the ones of the Testudo hosts. We identified two main genetic groups of H. aegyptium with no clear geographical structure. We believe that the existence of alternative hosts or the pet trade may explain some of these results. In the second study, we aimed to detect the presence of microorganisms and potential pathogens in H. aegyptium. The molecular screening detected the following parasites: Hemolivia mauritanica, Ehrlichia sp., Borrelia burgdorferi sensu lato, relapsing fever Borrelia, Francisella sp. and the microorganisms Candidatus Midichlora mitochondrii and Wolbachia sp. Despite the low prevalence of human pathogenic agents, these results highlight the potential consequences of the pet trade on disease emergence and the dispersion of pathogens and other microorganismsN/