Studying of Rickettsiae carried by Ixodes persulcatus in Yakeshi city, Inner Mongolia

  Objective  To investigate the infection status of spotted fever group Rickettsiae and Anaplasma in ticks in the Greater Khingan Mountains area, Inner Mongolia.

  Methods  Target genes of ticks collected in July, 2010 were amplified by using PCR and the positive DNA were send to sequence. The nucleotide sequences similarity was calculated with software MegAlign. Phylogenetic analysis was performed by using software phyML3.1.

  Results  We collected 293 ticks in Alongshan mountain area, which belonged to Ixodes persulcatus indicated by morphological identification. The infection rates of spotted fever group Rickettsiae and Anaplasma in the ticks were separately 9.56% and 0. Nucleotide sequence analysis confirmed that the spotted fever group Rickettsiae carried by the ticks was Candidatus Rickettsia tarasevichiae, the homology between the sequences obtained from this study and known reference sequences from GenBank was 100.00% for rrs gene, and 99.80% for gltA gene.The amino acid homology was 100.00%. Phylogenetic analysis indicated that the Candidatus Rickettsia tarasevichiae detected in this study in Ixodes persulcatus in Yakeshthis belonged to the same genotype of the strains detected in Russia.

  Conclusion  The pathogen Candidatus Rickettsia tarasevichiae was carried by Ixodes persulcatus in the Greater Khingan Mountains area, Inner Mongolia.