Cloning and sequencing of a species-specific nucleotide fragment of Borrelia burgdorferi sensu stricto, which is repeated in several plasmids of the species.

Among the etiological agents of Lyme disease, Borrelia burgdorferi sensu stricto strains carry a 16 kb plasmid, which did not hybridize to plasmids of B. garinii and B. afzelii strains. A 1271 bp DNA fragment of the 16 kb plasmid was cloned. It hybridized to several plasmids of this species (16, 27 and 55 kb). Sequencing of the cloned insert revealed a 327 bp ORF coding for a 14 kDa protein of unknown function, which could be expressed in E. coli. This ORF, conserved among B. burgdorferi sensu stricto strains, was carried by the same three plasmids.