[Spontaneous mixed infection in rodents with Borrelia and Leptospira]

This study was performed in a natural ITBB focus located in Perm' region of Russia. In 1993-1995, 73 root voles (Microtus oeconomus), collected in the forests, were examined by means of inoculation of internal organs on BSK-II medium. Borrelia were found in 13 animals (17.8%). According to the results in RLFP analysis 11 isolates were classified as B. garinii, 1 as B. afzelii and 1 as mixture of B. garinii and B. afzelii. In one case Leptospira, which was identified by PFGE analysis as grippotyphosa serovar, was found simultaneously with B. garinii in the BSK-II culture from urinary bladder. Our data testify to the fact of existence of mixed foci of leptospirosis and borreliosis. Moreover, one animal may serve as a reservoir host simultaneously of two different spirochetal agents.