Effects of live and peptide-based anti-microbiota vaccines on Ixodes ricinus fitness, microbiota and acquisition of tick-borne pathogens

This study explored the effects of anti-microbiota vaccines on the infection dynamics of Borrelia and Rickettsia in mice and the microbiota composition of Ixodes ricinus ticks. Using a murine model, we investigated the immunological responses to multi-antigenic peptide (MAP) and live Staphylococcus epidermidis vaccines. Mice were infected with Borrelia afzelii or Rickettsia helvetica and subsequently exposed to pathogen-free I. ricinus nymphs. We monitored tick feeding behavior, survival rates, and infection levels. Additionally, we employed comprehensive microbiota analyses, including alpha and beta-diversity assessments and microbial co-occurrence network construction. Our results indicate that both MAP and live S. epidermidis vaccines elicited significant antibody responses in mice, with notable bactericidal effects against S. epidermidis. The vaccination altered the feeding patterns and fitness of ticks, with the live vaccine group showing a higher weight and faster feeding time. Microbiota analysis revealed significant shifts in beta-diversity between vaccine groups, with distinct microbial networks and taxa abundances observed. Notably, the MAP vaccine group exhibited a more robust and complex network structure, while the live vaccine group demonstrated resilience to microbial perturbations. These findings suggest that anti-microbiota vaccination not only influences host immune responses but also significantly impacts the microbial assembly and infection susceptibility of ticks. This research provides insights into the potential use of microbiota-targeted vaccines in controlling tick-borne diseases.