SOUTHERN TAIGA COMBINED NATURAL FOCI OF SPIROCHETOSES

Aim. Study of possibility of existence of combined natural foci of spirochetoses (ixodes tick borrelioses and leptospiroses) in typical taiga forests, and their etiologic and reservoir-host structure. Materials and methods. Small mammals of 19 species were captured in 1992-2010 at a station in low-mountain southern taiga forests of Chusov area of Perm region. Borreliae were isolated by seeding urinary bladder or aural bioptates into BSK II medium, leptospirae - by seeding a suspension of kidney tissue into Vervoort-Wolf medium. 1350 animals were studied by seeding for borrelia infection and 1077 - for leptospira. 287 of those, small animals of 6 species, were simultaneously studied for borrelia and leptospira infection. Borrelia isolates were identified by using PCR and restriction fragment length polymorphism methods, and leptospirae - by using standard diagnostic agglutinating sera kit. Blood of 2893 rodents of 12 species and insectivorous of 7 species was studied in microagglutination reaction for the detection of antibodies against leptospirae. Results. Infection by Borrelia garinii and Borrelia afzelii or Grippotyphosa serogroup leptospira was detected in 6 most numerous species of forest small mammals. 3 root voles and 1 bank vole were simultaneously infected by borreliae and leptospirae. B.garinii and Grippotyphosa serogroup leptospira were simultaneously isolated from 2 root voles, and B.garinii and Javanica serogroup Leptospira interrogans - from 1 root vole. A bank vole was infected by B.afzelii and Javanica serogroup leptospira. Mixed-infected animals composed 1.4% of all animals of background species studied in parallel. Conclusion. The data obtained indicate a presence of natural foci of leptospiroses in the southern taiga forest pre-Urals. The data confirm the conceptions regarding a predominant presence in European forest ecosystems of foci with Grippotyphosa serogroup L.interrogans pathogen, and the main carrier of these leptospirae being bank vole. Combined natural foci of spirochetoses of two groups (ixodes tick borrelioses and leptospiroses) were detected.

spirochetoses, ixodes tick borrelioses, leptospiroses, combined natural foci