MOLECULAR SUBTYPING OF BORRELIA-BURGDORFERI IN ERYTHEMA MIGRANS AND ACRODERMATITIS CHRONICA ATROPHICANS

Recently, three subtypes of Borrelia burgdorferi have been identified: Borrelia burgdorferi sensu stricto, Borrelia garinii, and the VS 461 group of Borrelia burgdorferi. These subtypes differ by nucleotide seq uence variations within several Borrelia burgdorferi specific genes an d most likely by their pathogenetic potential. To assess whether diffe rent subtypes of Borrelia burgdorferi might be associated with differe nt cutaneous manifestations and clinial courses of Lyme disease, lesio nal skin biopsies from 35 patients with erythema migrans and 18 patien ts with acrodermatitis chronica atrophicans were analyzed. A Borrelia burgdorferi specific gene segment encoding a 26-kD protein with subtyp e specific nucleotide sequence variations was amplified by a nested po lymerase chain reaction technique. For molecular subtyping, the produc ts were transcribed into complementary RNA. Upon polyacrylamide gel el ectrophoresis, complementary RNA molecules separate into several metas table conformational forms resulting in patterns of bands highly speci fic for the nucleotide sequence of the transcribed molecules. In biops y specimens of erythema migrans, the VS 461 subtype was detected in 28 of 35 and the Borrelia garinii subtype in six of 35 cases. In one of 35 cases of erythema migrans Borrelia burgdorferi sensu stricto as wel l as Borrelia garinii was detected. In contrast, in all 18 biopsies of acrodermatitis chronica atrophicans, only the VS 461 subtype was iden tified. This subtype is rarely found in the USA, where acrodermatitis chronica atrophicans is almost unknown. These data indicate that acrod ermatitis chronica atrophicans might be closely associated with the VS 461 group of Borrelia burgdorferi.