FORMATION AND CULTIVATION OF BORRELIA-BURGDORFERI SPHEROPLAST-L-FORM VARIANTS

As clinical persistence of Borrelia burgdorferi in patients with activ e Lyme borreliosis occurs despite obviously adequate antibiotic therap y, in vitro investigations of morphological variants and atypical form s of B. burgdorferi were undertaken. In an attempt to learn more about the variation of B. burgdorferi and the role of atypical forms in Lym e borreliosis, borreliae isolated from antibiotically treated and untr eated patients with the clinical diagnosis of definite and probable Ly me borreliosis and from patient specimens contaminated with bacteria w ere investigated. Furthermore, the degeneration of the isolates during exposure to penicillin G in vitro was analysed. Morphological analysi s by darkfield microscopy and scanning electron microscopy revealed di verse alterations. Persisters isolated from a great number of patients (60-80%) after treatment with antibiotics had an atypical form. The m orphological alterations in culture with penicillin G developed gradua lly and increased,vith duration of incubation, Pleomorphism, the prese nce of elongated forms and spherical structures, the inability of cell s to replicate, the long period of adaptation to growth in MKP-medium and the mycoplasma-like colonies after growth in solid medium (PMR aga r) suggest that B. burgdorferi produce spheroplast-L-form variants. Wi th regard to the polyphase course of Lyme borreliosis, these forms wit hout cell walls can be a possible reason why Borrelia survive in the o rganism for a long time and the cell-wall-dependent antibody titers di sappear and emerge after reversion.