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Abstract(s)
Ticks are one of the main vectors of disease to animals worldwide. Mainly due to anthropogenic impact on our planet, environmental changes are expected to impact tick and tick-borne diseases ecology and distribution. Rhipicephalus ticks are widely distributed throughout Southern Europe.
Due to their unclarified taxonomic status, hidden diversity and unclear tick-host-pathogens interactions, assessments regarding the transmission potential of different species lineages and populations are not routinely performed.
Following the premise that different tick species have different potential to transmit tick-borne diseases, the main aim of this study was to clarify if different Rhipicephalus sanguineus s.l. lineages or species distributed throughout Southern Europe show a differentiated potential for pathogens transmission to their hosts. First, tick collections from European and African countries were used to assess Rhipicephalus genus diversity using morphologic and genetic-based methods. Screening techniques were then applied to investigate their microbiota composition. By last, a spatio-temporal variation study of tick-borne symbionts with different transmission routes was performed in a four years database from the Netherlands to assess if the bacteria composition of ticks could affect pathogens and endosymbionts prevalence in the vector.
Regarding the R. sanguineus s.l. diversity, our results evidence that the temperate lineage distributed in Southern Europe has at least two different morphotypes: “R. sanguineus” and “R. turanicus”. This result supports that a direct correlation between morphotype and transmission potential cannot be made based on the traditional paradigm, and additional methods should be used to confirm taxa identifications. Furthermore, our findings suggest that Coxiella-like endosymbiont diversity follow the Rhipicephalus species and lineages phylogeny, supporting not only a differentiated co-evolution as a different microbiota composition between lineages. By last, the results evidence significant associations between pathogens and endosymbionts, suggesting that microbiota composition can affect tick-borne pathogens prevalence within a tick, which ultimately could affect their transmission potential.
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Keywords
Rhipicephalus sanguineus s.l. lineages Biosystematics Co-phylogeny Statistical models Microbiota composition