Detection of tick-borne pathogens in ticks collected in the suburban area of Monte Romano, Lazio Region, Central Italy.

Background. A study on tick species characterization and tick borne pathogens detection was performed by a survey conducted during 2012 and 2013 in the Viterbo province (Lazio Region, Central Italy). Seven sites were selected for the study investigation, including two farms and a military zone. Methods. A total of 255 ticks, Rhipicephalus (Boophilus) annulatus (n = 215), Rhipicephalus bursa (n = 28), and Hyalomma marginatum (n = 12) were screened individually by molecular methods for the tick borne bacterial agents: Borrelia burgdorferi sensu lato group, Bartonella spp., Coxiella burnetii, Ehrlichia spp., Francisella spp., and Rickettsia spp. Results and conclusion. Overall, 182 ticks (71%) were infected with at least one pathogen; among these co-infections were found in 94 ticks. Tick borne pathogens identified were C. burnetii, B. burgdorferi s.l.., Bartonella spp., Rickettsia spp., Francisella spp., and Ehrlichia spp. In R. bursa and H. marginatum, the presence of B. burgdorferi s.l. was positively correlated with that of C. burnetii, Rickettsia spp., and Bartonella spp. and their coinfection probabilities were 29.8%, 22.7% and 11.7%, respectively; the probability of coinfection for Francisella spp. and Rickettsia spp. and for Francisella spp. and Bartonella spp. was 14.9% and 17.9%, respectively. In R. (Boophilus) annulatus, the probability of coinfection between C. burnetii and B. burgdorferi s. l. was 11.3%, while those between C. burnetii and Bartonella spp. and between B. burgdorferi s. l. and Bartonella spp. were 0.8%. Further studies are needed in order to assess the risk associated with these unusual tickborne pathogens in Central Italy.