Low bacterial infection in ticks infesting the cryptogenic common wall lizards (Podarcis muralis) in Poland

Lizards are important hosts for immature stages of ticks, including Ixodes ricinus , which is a major vector of tick-borne diseases. Recently, three populations of the common wall lizard ( Podarcis muralis ) were discovered in the Strzelin Hills, SW Poland, north of the continuous range of the species. However, their exact origin (introduction or relict) is contentious and data on their ecology remain scarce. For example, no information is available on their parasites. The aim of this study was to assess the infestation rate and bacterial infection level in ticks collected from P. muralis at the three quarry sites in Poland between April and October 2019. A total of 52 adult lizards were caught, of which 16 (30.8%) carried 51 ticks, including 14 nymphs and 37 larvae. All were identified as I. ricinus . A nested PCR method was used for DNA amplification of Borrelia spp., Rickettsia spp. and Anaplasma spp. The overall infection levels for Borrelia and Rickettsia were 2.0% (1/51) and 7.8% (4/51), respectively. Anaplasma was not detected in any of the samples tested. Sequencing confirmed the presence of B. lusitaniae and R. helvetica . The low prevalence of Borrelia and Rickettsia bacteria in ticks collected from P. muralis may be related to the species’ preference for well-lit open habitats with sparse vegetation and rocky surfaces. Therefore, further studies are needed to better understand the transmission dynamics of these bacteria between lizards and ticks in this specific habitat.