and in sensu stricto ticks collected on dogs in the Patagonian region of Argentina.

The aim of this study was to examine the presence of tick-borne rickettsial bacteria in sensu stricto ticks collected from dogs in the Patagonian region of Argentina. Fourteen stray dogs from Valcheta, Río Negro province, Argentina were examined for the presence of s.s. ticks. Ninety ticks were collected and identified to species level. DNA was extracted and analysed by conventional PCR assays for the presence of tick-borne bacteria belonging to the genera , and . Thirty-three tick pools were tested by different PCR assays of which 3 were positive for Anaplasmataceae bacteria. From the 3 Anaplasmataceae positive samples, 2 partial 16S rDNA sequences were generated and belonging to , the causative agent of canine cyclic thrombocytopenia. Two tick samples were positive in specific PCR assays and were identified by phylogenetic analysis as , a member of the spotted fever group rickettsiae. The results of this study demonstrate the molecular detection of 2 rickettsial bacteria in s.s. in a region of Argentina where no data were available so far.