Pathogens and symbionts in ticks: a survey on tick species distribution and presence of tick-transmitted micro-organisms in Sardinia, Italy

A total of 1485 adult ticks were collected from mammalian hosts in south-eastern Sardinia, Italy, during the years 2007-2008. Ticks were identified and tested by PCR analysis for presence of Rickettsia species of the spotted fever group, Ehrlichia canis, Anaplasma phagocytophilum, Coxiella burnetii, Bartonella species and Leishmania species. Among all tick species examined (Rhipicephalus sanguineus, Rhipicephalus turanicus, Rhipicephalus bursa, Rhipicephalus pusillus, Hyalomma marginatum marginatum, Haemaphysalis sulcata and Dermacentor marginatus), only Hyalomma marginatum marginatum produced negative results. A total of 22 pools belonging to the three tick species Rhipicephalus sanguineus (0.9 %), Rhipicephalus turanicus (4.5 %) and Rhipicephalus pusillus (100 %) were positive for Rickettsia species, while a total of five pools belonging to Rhipicephalus sanguineus (0.09 %), Haemaphysalis sulcata (16.7 %) and D. marginatus (7.8 %) were positive for E. canis. Five pools of Rhipicephalus turanicus (1.8 %) were positive for A. phagocytophilum. Positivity for C. burnetii was found in seven pools belonging to three tick species: Rhipicephalus sanguineus (0.5 %), Rhipicephalus turanicus (0.3 %) and Haemaphysalis sulcata (4.4 %). Finally, four pools belonging to Rhipicephalus sanguineus (0.09 %), Rhipicephalus turanicus (0.7 %) and Rhipicephalus bursa (1.1 %) were positive for Bartonella species. Leishmania species DNA was not detected in any of the tick pools examined. Data presented here increase our knowledge on tick-borne diseases in Sardinia, and provide a useful contribution to understanding their epidemiology.