Spotted Fever Group Rickettsiae in Ticks and Small Mammals from Grassland and Forest Habitats in Central Germany.

Rickettsiae of the spotted fever group (SFG) are zoonotic tick-borne pathogens. Small mammals are important hosts for the immature life stages of two of the most common tick species in Europe, and . These hosts and vectors can be found in diverse habitats with different vegetation types like grasslands and forests. To investigate the influence of environmental and individual factors on prevalence, this study aimed to analyse the prevalence of SFG rickettsiae in ticks and small mammals in different small-scale habitats in central Germany for the first time. Small mammals of ten species and ticks of two species were collected from grasslands and forests in the Hainich-Dün region, central Germany. After species identification, DNA samples from 1098 ticks and ear snips of 1167 small mammals were screened for DNA by qPCR targeting the gene. Positive samples were retested by conventional PCR targeting the gene and sequencing. DNA was detected in eight out of ten small mammal species. Small mammal hosts from forests (14.0%) were significantly more often infected than those from grasslands (4.4%) ( < 0.001). The highest prevalence was found in the mostly forest-inhabiting genus (14.8%) and the lowest in (6.6%), which inhabits grasslands. The prevalence was higher in (46.3%) than in the complex (8.6%). Adult ticks were more often infected than nymphs ( = 0.0199). All sequenced rickettsiae in complex ticks were , and the ones in were . Unlike adults, questing nymphs have had only one blood meal, which explains the higher prevalence in adults. Interestingly, habitat type did influence infection probability in small mammals, but did not in ticks. A possible explanation may be the high prevalence in and which were more abundant in the forest.