Acronym: TICK-SAVE TICK microbiome and pathobiome interactions with biotic factors to mitigate their SpreAd via wild VErtebrate hosts

• Applicants: Dr. Susanne Fischer; Dr. Jan Gogarten; Dr. Anna Obiegala
• Subject Area: Microbial Ecology and Applied Microbiology ; Parasitology and Biology of Tropical Infectious Disease Pathogens
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 569064523

State of the Art: Tick-borne diseases are an increasing public health concern, with Ixodes ricinus serving as a primary vector in Europe. Environmental factors, land-use changes, and host availability significantly influence tick density, pathogen prevalence, and microbiome diversity. However, the interactions between these factors remain insufficiently understood. Previous studies have identified that disturbed habitats can impact pathogen transmission and microbial communities in ticks, yet detailed phylogeographic and microbiome analyses are lacking. This study aims to fill these gaps by integrating ecological, molecular, and bioinformatics approaches to understand tick-pathogen-microbiome interactions. The aims are to (1) investigate how land-use intensity and forest structure affect tick density and pathogen prevalence; to (2) examine relationships between host abundance, landscape variables, and tick density; to (3) compare microbial communities in ticks from disturbed (FOX plots) and undisturbed sites; to (4) assess correlations between the tick microbiome and pathogen prevalence; to (5) recover and analyze Borrelia genomes from I. ricinus ticks to explore phylogeographic variations and to (6) establish phylogeographic maps of tick populations and relate them to pathogen prevalence and Borrelia diversity. Methods: 1) Field Sampling: Questing ticks will be collected from experimental and FOX plots in three Biodiversity Exploratories (BEs) in Germany across all seasons (2026-2027). Tick density will be quantified in relation to forest structure and land-use practices. 2) Tick and Pathogen Analysis: Collected ticks will be taxonomically identified, and DNA will be extracted for further analysis. Borrelia prevalence and genospecies will be determined using qPCR and MLST sequencing. 3) Microbiome Analysis: The tick microbiome will be characterized using 16S rRNA sequencing, with comparisons between disturbed and undisturbed plots and correlation with pathogen presence. 4) Phylogenetic and Statistical Analysis: Genetic relationships among tick populations will be assessed using mitochondrial markers, and phylogenetic trees will be constructed. Statistical models (GLMM, PERMANOVA) will be applied to evaluate the influence of environmental and biotic factors on tick density, pathogen prevalence, and microbiome diversity. This research aims to identify the land-use factors that influence tick density and the risk of pathogen transmission. It will explore how forest gaps and disturbed habitats affect the composition of the tick microbiome and their pathogen load. Additionally, the study will examine the impact of host abundance and microclimatic conditions on shaping tick populations. This study will enhance our understanding of the ecological drivers of tick-borne diseases, informing conservation and public health strategies.

• DFG Programme: Infrastructure Priority Programmes
• Subproject of: SPP 1374: Biodiversity Exploratories