The aim of the study was to determine prevalence of Anaplasmataceae-infected ticks in the Black Sea Coast and the Pleven regions of Bulgaria. A total of 350 ticks from different tick species were collected. Two hundred fifty-five ticks were removed from dogs in the Black Sea Coast region, and 95 Ixodes ricinus ticks were collected by flagging vegetation with a white flannel cloth in two areas in the region of Pleven. After the DNA isolation of the ticks, a genus-specific polymerase chain reaction (PCR) was performed to identify Anaplasmataceae. Second PCRs were performed with species-specific primers to identify Ehrlichia canis (E. canis) and Anaplasma phagocytophilum (A. phagocytophilum). The results showed that 26.9% of the Ixodes ricinus ticks were infected with Anaplasmataceae in the Black Sea Coast region and 36.8% in the Pleven region. The infection with E. canis was detected in 35.7% and A. phagocytophilum in 25.0% of positive ticks from the Black Sea Coast region. In the Pleven region, 22.9% of ticks were positive for E. canis, while 42.9% were positive for A. phagocytophilum. The molecular identification of E. canis in ticks collected from Bulgaria was performed for the first time. In conclusion, the present study revealed a higher prevalence of ticks infected with Anaplasmataceae, particularly A. phagocytophilum, in the Pleven region than in the Black Sea Coast region.
Keywords: A. phagocytophilum; Anaplasmataceae; E. canis; species-specific PCR.