158 | Tick-borne pathogens in wild ungulates from Sicily (southern Italy): molecular detection and characterization

Tick-borne pathogens (TBPs) represent a major concern for animal and public health due to their complex transmission cycles and zoonotic potential. In recent years, increasing interactions among wildlife, domestic animals, and humans have favoured the circulation of TBPs, particularly in areas characterized by high host density and suitable environmental conditions for tick vectors. Wild ungulates play a key role in maintaining TBPs, acting both as reservoirs and as hosts for ticks [1,2]. In Sicily (southern Italy), the uncontrolled expansion of fallow deer (Dama dama) and wild boar (Sus scrofa) populations may significantly influence the epidemiology of these pathogens. This study aimed to investigate the occurrence of TBPs and to molecularly characterize the detected pathogens in wild ungulates culled in Sicily as part of regional population management programs. A total of 142 carcasses (83 fallow deer and 59 wild boars) were subjected to sanitary inspection and necropsy, with the collection of multiple organ samples and attached ticks. Ectoparasites were identified by morphological keys under a stereomicroscope [3]. Molecular analyses were performed by PCR and sequencing to detect DNA of Piroplasms (Babesia spp. and Theileria spp.)[4], Anaplasma spp. [5] and Rickettsia spp. [6], and by RT-PCR to amplify Borrelia burgdorferi sensu lato DNA [7]. Overall, n. 266 ticks were collected from carcasses, with n. 189 specimens collected from fallow deer and n. 77 from wild boar. Ticks belonged to four different species, with Ixodes ricinus being the most prevalent (n. 141 specimens, 53.0%), followed by Dermacentor marginatus (n. 67, 25.2%), Haemaphysalis punctata (n. 46, 17.3%) and Hyalomma lusitanicum (n. 12, 4.5%). Piroplasms were detected in 22.5% of the examined animals, Anaplasma spp. in 40.8% and Rickettsia spp. in 2.8%. All the samples were negative for B. burgdorferi sensu lato. Sequence analysis identified Theileria cervi, Theileria ovis, Theileria capreoli and Babesia sp. among piroplasms, while Anaplasma phagocytophilum and Rickettsia slovaca were detected among the bacterial pathogens. The detection of multiple TBPs confirms their role in the maintenance and circulation of zoonotic pathogens in the Sicilian ecosystem. The coexistence of these pathogens with competent vectors and susceptible hosts, together with increasing wild ungulate densities, may facilitate pathogen transmission to livestock and humans. Continuous monitoring of TBPs in wild ungulates is thus critical for improving risk assessment and supporting integrated One Health strategies aimed at mitigating pathogen interspecies transmission. This study has been funded by the Italian Ministry of Health grant number: GR-2021-12373930.