Coxiella burnetii detected in Rhipicephalus sanguineus ticks collected in Portuguese autochthonous livestock.

Coxiella burnetii is a bacterium that causes coxiellosis in animals and Q fever in humans. While ruminants are the main reservoirs, the role of ticks in their transmission is still uncertain. This study looked for C. burnetii in ticks collected from two autochthonous breeds in Portugal: Churra Galega Mirandesa sheep and Garrano horses. A total of 555 ticks were tested, including 100 Rhipicephalus sanguineus sensu (s.) stricto (s.) from sheep and 455 Rhipicephalus bursa from horses. Coxiella burnetii was found in 7 % of R. sanguineus s.s., but not in R. bursa. Phylogenetic analysis confirmed the strains. These findings suggest that R. sanguineus s.s. may play a role in the bacterium's presence in livestock. Further research is needed to clarify the role of ticks in C. burnetii transmission in Portugal.