Ubiquity of Rickettsia aeschlimannii in ambushing free ranging Hyalomma marginatum Koch, 1844 ticks from Pianosa Island, Italy.

Hyalomma spp. ticks in the protected area of Pianosa Island, Italy, were monitored and investigated in their bacterial content (575 specimens, composed in 120 pools) through metabarcoding sequencing. We report the dominance of H. marginatum, harbouring at high prevalence (58% glt-, and 75% 17kDa-Ag protein-positive pools) Rickettsia aeschlimannii, an agent of the Spotted Fever Group . These findings pose questions on the risk of transmission of Spotted Fever and deserve further studies on host-pathogen interaction and dynamics within the island settings.