PRESENT STATUS OF LYME BORRELIOSIS AND CH ARACTERIZATION OF LYME-DISEASE BORRELIA ISOLATED IN JAPAN

Lyme disease is a multisystemic disorder caused by infection with Borr elia burgdorferi sensu late which is carried by ticks of the Ixodes ri cinus complex. The agent was discovered in 1982 in North America and t he disease is recognized as an emerging infectious diseases in North A merica and Europe. Japanese Borrelia isolates were characterized by ge netic and immunologic analysis. Isolates from Ixodes ovatus were found to be unique by DNA/DNA hybridization analysis, restriction fragment length polymorphism analyses of the flagellin gene and the 16S rRNA ge nes, and were described as new species, Borrelia japonica. Isolates fr om Ixodes persulcatus were determined as Borrelia garinii and Borrelia afzelii. However, B. garinii found in Japan was different from those from Europe in immunologic and genetic characteristics of outer surfac e protein A, but B. afzelii isolates from Japan and Europe were identi cal. An experimental model of arthritis related to Lyme disease using outbred ddY mice was established. Whole cell vaccine prepared from Nor th American and European isolates could not elicit protective immunity against infection of Japanese isolates. This implies that vaccine dev elopment using Japanese isolates is necessary. Borrelia bound specific ally to galactosylceramide (GalCer), glucosylceramide and lactosylcera mide which are present in various types of cells as binding receptor, but not to other glycosphingolipids. Furthermore, the infectivity of B orrelia may be associated with the binding to glycosphingolipids on th e cell. surface and a 67 kilodalton protein of Lyme disease Borrelia m ay be involved in binding of Borrelia to GalCer.