Granulocytic ehrlichiae in Ixodes persulcatus ticks from an area in China where Lyme disease is endemic

A total of 372 adult Ixodes persulcatus ticks were collected from vegetatio n in a forest area of Heilongjiang Province in northeastern China, where Ly me disease is known to be endemic. The ticks were examined for the presence of granulocytic ehrlichiae by heminested PCR with primers derived from the 16S rRNA gene. Of 310 ticks obtained from the Dahe forestry farm, two pool s (each containing 5 ticks) were found positive, with a minimum infection r ate of 0.6%. Ehrlichial DNA was also detected in one female (1.6%) of 62 ti cks collected from the Yulin forestry farm. The overall minimum infection r ate of the 372 I. persulcatus adults was 0.8%. The nucleotide sequences of 919-bp PCR products from the three positive tick specimens were identical t o each other and very closely related to the members of the Ehrlichia phago cytophila genogroup. This is the first identification of granulocytic ehrli chiae in ticks in Asia and the first report of infection in I. persulcatus anywhere.