Metagenomic 16S rRNA gene sequencing survey of Borrelia species in Irish samples of Ixodes ricinus ticks

The spirochetal bacterium Borrelia miyamotoi is a human pathogen and has been identified in many countries throughout the world. This study reports for the first time the presence of Borrelia miyamotoi in Ireland, and confirms prior work with the detection of B. garinii and B. valaisiana infected ticks. Questing Ixodes ricinus nymph samples were taken at six localities within Ireland. DNA extraction followed by Sanger sequencing was used to identify the species and strains present in each tick. The overall rate of borrelial infection in the Irish tick population was 5%, with a range from 2% to 12% depending on the locations of tick collection. The most prevalent species detected was B. garinii (70%) followed by B. valaisiana (20%) and B. miyamotoi (10%). Knowledge of Borrelia species prevalence is important and will guide appropriate selection of antigens for serology test kit manufacture, help define the risk of infection, and allow medical authorities to formulate appropriate strategies and guidelines for diagnosis and treatment of Borrelia diseases.