MOLECULAR TYPING OF BORRELIA-BURGDORFERI FROM LYME-DISEASE PATIENTS BY PCR-RESTRICTION FRAGMENT LENGTH POLYMORPHISM ANALYSIS

Ninety-three Borrelia burgdorferi isolates obtained from erythema migr ans lesions or blood of Lyme disease patients in Westchester County, N .Y., between 1991 and 1994 were characterized by PCR-restriction fragm ent length polymorphism (PCR-RFLP) analysis of the 16S-23S rRNA gene s pacer. All isolates could be classified into three distinct RFLP types , Among the 82 skin biopsy isolates studied, 21 (25.6%) were type 1, 3 7 (45.1%) were type 2, and 21 (25.6%) were type 3. Three (3.7%) cultur es contained a mixture of two isolates with distinct RFLP types, The 1 1 isolates cultured from blood showed a similar predominance of RFLP t ype 2 (6 of 11; 54.5%) relative to types 1 (2 of 11; 18.2%) and 3 (3 o f 11; 27.3%). For one patient both skin and blood isolates were cultur ed, and RFLP analysis revealed that these isolates differed from one a nother, This study demonstrates that there is genotypic heterogeneity in B. burgdorferi strains infecting Lyme disease patients, and this ty ping approach may allow differentiation of isolates with various degre es of pathogenic potential.