MOLECULAR SUBTYPING OF BORRELIA-BURGDORFERI SENSU-LATO ISOLATES FROM 5 PATIENTS WITH SOLITARY LYMPHOCYTOMA

Solitary lymphocytoma is a rare cutaneous manifestation of Lyme borrel iosis that has been reported almost exclusively from Europe. This sugg ests that its etiologic agent may be absent or extremely rare on the N orth American continent. All three species of B. burgdorferi sensu lat e known to be associated with human Lyme borreliosis (B. burgdorferi s ensu stricto, B. garinii, and B. afzelii) have been isolated in Europe , whereas only B. burgdorferi sensu stricto has been found in North Am erica. This suggests that either B. garinii or B. afzelii might be the etiologic agent of borrelial lymphocytoma. To investigate this hypoth esis we characterized five strains of B. burgdorferi sensu lato isolat ed from lymphocytoma lesions of patients residing in Slovenia. The met hods used included: large restriction fragment pattern analysis of res triction enzyme MluI-digested genomic DNA, plasmid profiling, protein profiling, ribotyping using 5S, 16S, and 23S rDNA probes, and polymera se chain reaction amplification of the rrf (5S)-rrl (23S) intergenic s pacer region. Molecular subtyping showed that four of the five isolate s belonged to the species B. afzelii; however, this species is the pre dominant patient isolate in Slovenia and, therefore, may not represent a preferential association with lymphocytoma. The fifth isolate appea red to be most closely related to the DN127 genomic group of organisms , Further characterization of the isolate revealed that it possessed a unique molecular ''fingerprint.'' The results not only show that borr elial lymphocytoma can be caused by B. afzelii but also demonstrate an association with another genomic group of B. burgdorferi sensu late t hat is present in North America as well.