One Health tick bite exposure biomarkers against Ixodes ricinus salivary peptides

The changing distributions and activity patterns of tick populations underscore the urgent need for enhanced surveillance and risk assessment strategies for ticks and tick-borne diseases (TBDs) affecting humans and animals. Biomarkers of exposure to tick salivary peptides can be used to identify tick bite history and to monitor tick species distributions. Here, we derived peptides from previously identified immunogenic proteins, namely IrCalreticulin, IrLip1, and IrSPI. Bioinformatic predictive analysis of 3D structure and computed docking strength were used to identify candidate peptides based on predicted immunogenicity and arthropod homology. Using ELISA, several peptides distinguished sera from experimentally Ixodes ricinus -exposed and unexposed sheep for both IgM and IgG antibodies, as was true for clinical patient samples IgG positive for tick-borne Borrelia bacteria. These findings offer the potential for developing new effective strategies for the surveillance of ticks and TBDs, disease diagnostic guidance as well as assessing tick population control strategies.