GENETIC AND PHENOTYPIC CHARACTERIZATION OF BORRELIA-BURGDORFERI STRAINS ISOLATED FROM IXODES-RICINUS TICKS IN THE PROVINCE OF BOLZANO, ITALY

Lyme disease is caused by three borrelial species, B. burgdorferi sens u stricto, B. garinii and Borrelia group VS461. In a restricted biotop e of the Bolzano province, in the Caldaro community, five clones of tw o borrelial variants were isolated from Ixodes ricinus ticks. A prelim inary serological study showed that the two variants cross-reacted wit h B. burgdorferi B31 and B. garinii N34 strains, respectively. The iso lates were genomically related with strains B31 and N34; respectively, sharing a similar plasmid and restriction fragment length polymorphis m profile with these strains. The phenotypic pattern of the Caldaro is olates - namely their - protein and antigenic profile - showed infra-s ubspecific variation compared to related strains B31 and N34 respectiv ely. The observed phenotypic variability between strains isolated from the same biotope and in the same tick host strongly indicated the var iability of gene-encoded characters is a constant characteristic of bo rrelial strains, even when from the same ecological niche.