Presence of Roe Deer Affects the Occurrence of Anaplasma phagocytophilum Ecotypes in Questing Ixodes ricinus in Different Habitat Types of Central Europe

摘要

The way in which European genetic variants of circulate in their natural foci and which variants cause disease in humans or livestock remains thus far unclear. Red deer and roe deer are suggested to be reservoirs for some European strains, and is their principal vector. Based on gene sequences, five ecotypes have been identified. Ecotype I is associated with the broadest host range, including strains that cause disease in domestic animals and humans. Ecotype II is associated with roe deer and does not include zoonotic strains. In the present study, questing were collected in urban, pasture, and natural habitats in the Czech Republic, Germany, and Slovakia. A fragment of the gene of was amplified by real-time PCR in DNA isolated from ticks. Positive samples were further analyzed by nested PCRs targeting fragments of the rRNA and genes, followed by sequencing. Samples were stratified according to the presence/absence of roe deer at the sampling sites. Geographic origin, habitat, and tick stage were also considered. The probability that is a particular ecotype was estimated by a generalized linear model. was identified by genetic typing in 274 ticks. The majority belonged to ecotype I (63.9%), 28.5% were ecotype II, and both ecotypes were identified in 7.7% of ticks. Ecotype II was more frequently identified in ticks originating from a site with presence of roe deer, whereas ecotype I was more frequent in adult ticks than in nymphs. Models taking into account the country-specific, site-specific, and habitat-specific aspects did not improve the goodness of the fit. Thus, roe deer presence in a certain site and the tick developmental stage are suggested to be the two factors consistently influencing the occurrence of a particular ecotype in a positive tick.