This paper describes the detection of Piroplasmida DNA in the blood of horses. 166 blood samples of horses from five districts of the Irkutsk region were studied. The high piroplasms infection rate in horses (69 %) was found. For six positive samples nucleotide sequences were determined. The comparison of determined 18S rRNA gene sequences with previously published sequences showed that all revealed piroplasms DNA samples are Theileria equi. The data are presented on the lethal cases of equine piroplasmosis in the Irkutsk region in 2008.
The article sums up long-term, researches of studying of species and genetic variety of tick infections pathogens in combined, natural focuses of the Eastern Siberia. The results of the research testify to the high genetic variety of regional population, of tick-borne encephalitis virus that is represented, by the strains of Far-Eastern, West, Ural-Siberian genotypes, the strains of the group 886 and. 178-79. Infection of Ixodidae by the next pathogens: B. garinii, B. afzelii, R. sibirica, R. raoultii (генотипы. R. sp. DnS14, R. sp. DnS28), E. muris, A. phagocytophilum и Candidatus «Neoehrlichia mikurensis» was determined.