Rickettsia slovaca and Rickettsia raoultii in Dermacentor marginatus and Dermacentor reticulatus ticks from Slovak Republic

Rickettsiae, obligate intracellular Gram-negative bacteria, responsible for mild to severe diseases in humans are associated with arthropod vectors. and are known vectors of and distributed across Europe. A total of 794 , and adult ticks were collected from the vegetation, removed from horses, sheep, goats and dogs in Slovakia. The DNA of sp. was found in 229 ticks by PCR amplifying parts of , and genes. Next analyses of -positive samples by PCR-RFLP and/or sequencing showed ticks were more infected with and were more infected with . The prevalence of was 8.1-8.6% and 22.3-27% in and , respectively. The prevalence of was 20.6-24.3% in and 1.7-3.4% in . Intracellular growth of isolate from tick was evaluated by rOmpA-based quantitative SybrGreen PCR assay. The highest point of multiplication was recorded on the 7th and 8th day postinfection in Vero and L929 cells, respectively. was transmitted during feeding of -positive ticks to guinea pigs and subsequently rickettsial infection was recorded in all organs, the highest infection was in spleen, liver and heart. Our study describes the detection and isolation of tick-borne pathogens and , show that they are spread in Slovakia and highlight their risk for humans.