Characterization of Borrelia burgdorferi sensu lato isolated in Moscow province--a sympatric region for Ixodes ricinus and Ixodes persulcatus.

The relationships between Borrelia species and the vector ticks, Ixodes persulcatus and Ixodes ricinus were examined in a molecular epidemiological study. We conducted a survey in the Moscow region which is a sympatric region for both species of tick. We examined 630 unfed I. ricinus and I. persulcatus, ticks collected from four different regions around Moscow within an area of 250 km2. Eighty-four ticks were culture positive (13.3%) and the prevalence rate varied in each region from 5.7% to 42.3%. No difference was found between the total prevalence rate for both species. Eight Borrelia afzelii-like variant isolates from I. ricinus and Clethrionomys glareolus were identified as B. afzelii by flagellin gene and 16S rDNA sequence analyses. Most isolates from I. ricinus were identified as Borrelia garinii type 20047 and B. afzelii. Two isolates were identified as Borrelia burgdorferi sensu stricto (s.s.) and Borrelia valaisiana, respectively, but no B. garinii type NT29 was found. In contrast, isolates from I. persulcatus were identified as both types 20047 and NT29 of B. garinii, and B. afzelii. No B. burgdorferi s.s. isolate was found among isolates from I. persulcatus.

New genomospecies related to Borrelia valaisiana, isolated from mammals in Okinawa archipelago, Japan.

In 2000 and 2001, a survey was conducted of Borrelia isolated from various mammals in the southernmost islands of Japan, including Okinawa (main island), Izena, Iriomote and Ishigaki. Isolates obtained from the ear tissues of Suncus murinus (10 isolates), Mus calori (four isolates), Rattus norvegicus (one isolate) and Crocidura watasei (one isolate), were characterized by RFLP of the 5S-23S rDNA intergenic spacer and sequence analysis of the intergenic spacer, 16S rDNA and flagellin gene. While these isolates showed identical RFLPs to Borrelia valaisiana found in Korea, Taiwan and the southern and central parts of China, their RFLP patterns differed from those of B. valaisiana found in European countries, and strain Am501 isolated from Ixodes columnae in Japan. It was found that these isolates clustered with each other on a phylogenetic tree based on flagellin gene and 16S rDNA sequences, but were relatively divergent from the European B. valaisiana and strain Am501. These findings suggest that these isolates found in East Asia should be classified as a new genomospecies of Borrelia burgdorferi sensu lato.