Anaplasma spp. in domestic ruminants: evidence of circulation and molecular analysis of Anaplasma phagocytophilum and Anaplasma capra in Slovakia.

The geographic expansion of ticks in Europe has increased exposure to tick-borne pathogens, particularly Anaplasma phagocytophilum, the causative agent of anaplasmosis in humans and animals. The recently described A. capra has raised interest as an emerging tick-borne agent with potential veterinary and public health relevance. This study aimed primarily to assess the molecular occurrence of A. phagocytophilum in domestic ruminants and secondarily to screen for the presence of A. capra in Slovakia. From 2023 to 2025, 466 blood samples were collected from sheep (n = 183), goats (n = 118), and cattle (n = 165) from farms in Slovakia. Samples were tested by nested PCR targeting the 16S rRNA gene of Anaplasma spp. Subsequently, Anaplasma-positive samples were screened for A. capra using a groEL gene-based assay. All Anaplasma-positive amplicons were confirmed by Sanger sequencing. No Anaplasma DNA was detected in cattle, whereas 15 sheep (8.2%) and 13 goats (11.0%) were PCR-positive for Anaplasma spp. Sequencing and phylogenetic analysis confirmed all positive samples as A. phagocytophilum, with 99.08-100% identity to reference sequences. Comparative analysis of the partial 16S rRNA fragment revealed nine sequence variants among domestic ruminants, including a dominant variant shared by sheep and goats. A. capra DNA was not detected in any screened sample. The detection of A. phagocytophilum DNA in sheep and goats provides baseline molecular evidence of its occurrence in small ruminants in Slovakia. However, because only a partial 16S rRNA fragment was analysed and no tick samples were included, conclusions regarding strain-level diversity, local transmission cycles, and zoonotic relevance should be interpreted cautiously.