PERSISTENCE OF BORRELIA-BURGDORFERI SENSU LATE IN RESOLVED ERYTHEMA MIGRANS LESIONS

Erythema migrans skin lesions resulting from a tick bite and infection with Borrelia burgdorferi sensu late eventually resolve, even without antibiotic therapy, The aim of the present study was to gauge the fre quency of persistence of B. burgdorferi sensu late in such lesions, Th us, the site of a previous lesion was biopsied and cultured in 48 pati ents: 39 with systemic or localized symptoms/signs and nine with no sy mptoms. B. burgdorferi sensu late was isolated from biopsied skin from three symptomatic patients, Cultures of other tissues and fluids were negative, By genospecies-specific polymerase chain reaction (PCR) and pulsed-field gel electrophoretic (PFGE) analysis, two isolates were c lassified as Borrelia afzelii. The remaining isolate was a member of a n unusual group of strains that type as B. burgdorferi sensu stricto b y genospecies PCR but possess an atypical PFGE profile, All three pati ents had a dramatic clinical response to antibiotic treatment. These f indings demonstrate the capacity of viable B. burgdorferi sensu late o rganisms to persist in clinically normal-appearing skin at the site of a resolved erythema migrans rash for periods ranging from 2 months to 3.5 years, This observation may provide new insight into the organism s' ability to evade the host's immune response.