BackgroundTick-borne diseases are a major health risk for humans and dogs. In
addition to collection and analysis of questing ticks, analysis of host-
associated ticks for the presence of pathogens is a valuable method to gain
insight into transmission patterns of tick-borne diseases.MethodsTicks were
collected from dogs living in the Berlin/Brandenburg area. The three tick
species Ixodes ricinus, Ixodes hexagonus and Dermacentor reticulatus were
examined for the presence of Babesia spp., Borrelia spp., Rickettsia spp. and
Anaplasmataceae. Conventional PCR followed by sequencing was used for pathogen
detection and characterization.Results Babesia spp. were found in 2.5% and 3%
of I. ricinus and I. hexagonus, respectively. Sequencing revealed the presence
of Babesia microti, Babesia capreoli and Babesia venatorum. D. reticulatus
were free of Babesia canis. Rickettsia spp. were detected in 61% of I.
ricinus, 44% of I. hexagonus and 39% of D. reticulatus. Specifically detected
were Rickettsia raoulti in D. reticulatus and I. hexagonus, Rickettsia
helvetica in I. ricinus and I. hexagonus and Rickettsia monacensis in I.
hexagonus. Anaplasma phagocytophilum and Candidatus Neoehrlichia mikurensis
have been reported previously in I. ricinus (6.5% and 4.3%, respectively) and
I. hexagonus (3.9% and 5.9%). Borrelia spp. were found in 11.6% of I. ricinus
and 11.2% of I. hexagonus. Subsequent genospecies analysis revealed Borrelia
afzelii, Borrelia garinii, Borrelia burgdorferi sensu stricto and Borrelia
miyamotoi. Simultanous presence of more than one pathogen was found in 20% of
I. ricinus and in 59% of I. hexagonus whereas the total frequency of any
pathogen was 65% in I. ricinus, 59% in I. hexagonus and 64% in D. reticulatus.
Ticks in which A. phagocytophilum was detected had a significantly increased
risk of also containing Rickettsia. Ticks harbouring a pathogen had
significantly higher scutal indices than ticks without presence of any
pathogen.ConclusionsFrequencies of potential human or canine pathogens in
ticks were considerable and DNA of all four groups of pathogens was detected.
Differences in scutal indices might suggest that pathogens are frequently
taken up by ticks when feeding on dogs in Berlin/Brandenburg
