Interrogating the gut microbiota from several human-biting tick species in Northwestern Spain

Tick-borne diseases have increased significantly in recent years in Europe and especially in Spain. One of the strategies that have begun to be explored for their surveillance and control is related to the microbiota of ticks, which has focused on establishing the relationships between pathogens and endosymbionts that compose this microbiota and how these relationships can alter the vectorial capacity of these arthropods. In this sense, one of the first element consists of describing the composition and diversity of the bacterial communities that compose the microbiota of ticks inhabiting certain territories. Therefore, this work aimed to describe the microbiota of 29 individuals of 5 species of ticks collected in 4 provinces of Castilla y Leon in northwestern Spain, between 2015 and 2022. DNA extraction and sequencing of the V4 hypervariable region of 16S rRNA was performed, with subsequent analysis of diversity, taxonomic composition, and correlations between the different genera. There were no differences in the alpha diversity of the different species, nor were compositional changes evident at the phylum level. However, inter-individual differences at the genus level allowed spatial differentiation of the 5 species included in the study. Correlation analyses showed complex interactions between different genera of pathogens and endosymbionts with other members of the microbiota. These results provide a first approximation to the composition of the intestinal microbiota of different tick species from northwestern Spain, which can contribute to establishing surveillance and control actions specifically directed to tick species to reduce diseases such as Rickettsiosis, Lyme disease, and Crimean-Congo Hemorrhagic fever.