Coxiella-like endosymbiont associated to the "Anatolian brown tick" Rhipicephalus bursa in Southern Italy

Several different ticks have been reported to harbor microbes related to Coxiella burnetii, the agent of the Q fever. Rhipicephalus bursa is an important vector of tick-borne diseases in livestock in Mediterranean area; it is also abundant in ovi-caprine farms with C. burnetii infection, in Southern Italy. 60 females of Rh. bursa (15 pools) and 40 their eggs (2 pools) were screened for C. burnetii by a conventional PCR targeting the insertion sequence IS1111 and by Loop mediated isothermal amplification assay (LAMP) targeting com1 gene. One of 15 tick pools (1/15) and both egg pools (2/2) were found positive by LAMP assay and negative by PCR targeting IS1111 gene. 16S rRNA gene was amplified by PCR from the LAMP-positive pools, amplicons were sequenced and found 95% similar to the corresponding sequences from C. burnetii. This let us to hypothesize the presence of a new Coxiella-like endosymbiont associated with Rh. bursa which could be vertically transmitted, described here for the first time. The lack of detection of IS1111 in Coxiella endosymbiont of Rh. bursa could be related to the possible absence of the Pathogenicity island of C. burnetii, to which IS1111s are associated.