Ixodes ricinustick bacteriome alterations based on a climatically representative survey in Hungary

Abstract

Background: The microbial communities of disease vectors may represent a key feature in several biological functions, and thus deserve special attention in light of climate change and the consequent need for the development of novel control strategies. Nevertheless, vector-borne microbial networks are still poorly understood. Assessing the microbial interactions and climatic dependencies of vectors may contribute to better estimating pathogen transmission characteristics, public health risks and the urge for control steps. Results: After the collection of Ixodes ricinus ticks from a climatically representative set of sampling points in Hungary and the next generation sequencing based acquisition of metagenomic shotgun sequencing datasets. Furthermore, reports of the core bacteriome constituting of higher agglomerated genus-level relative abundance read counts than 1% in at least one of the samples, along with and β-diversity and the statistically significant differences and correlations of the genus-level bacterial relative abundances were presented in various developmental stage tick groups. Besides these, the identified pathogenic bacteria were also listed. Genera constituting the core bacteriome (Arsenophonus, Bacillus, Candidatus Midichloria, Curtobacterium, Cutibacterium, Mycobacteroides, Pseudomonas, Rhodococcus, Rickettsia, Sphingomonas, Staphylococcus, Stenotrophomonas and Wolbachia) showed several significant relative abundance differences and correlations among developmental stages and at sampling points with different climatic conditions. Reads of pathogenic bacteria from the genera of Anaplasma, Borrelia, Borreliella, Ehrlichia, Rickettsia were associated with the developmental stage and the sampling geolocation of the host ticks. Conclusions: The composition and correlations of vector-borne microbiota members showed significant alterations at sampling points with different temperature and precipitation histories and at the various developmental stages of the tick hosts. Our findings not only pave the way towards the understanding of tick-borne bacterial networks and interdependencies, but also raise light to the high potential for the presence of a possible biological tick control species, the tick parasitoid, Ixodiphagus hookeri based on related bacteriome patterns. The results of conscious tick microbiome assessment studies may contribute to the precision tick control strategies of the future.