Isolation and characterization of the Lyme disease spirochete from the skin of patients with erythema chronicum migrans.

The Lyme disease spirochete, which had previously been isolated with difficulty from human skin lesions of erythema chronicum migrans of Lyme disease, was grown from six of fourteen skin biopsies cultured in a newly modified Kelly's medium. In two instances the Lyme disease spirochetes that were grown were also seen in histopathologic sections. Organisms grew in clumps in liquid culture medium. All six isolates reacted with a monoclonal antibody to a 31,000-dalton outer membrane protein. Only three of six reacted to a monoclonal antibody to a 34,000-dalton outer membrane protein, suggesting that different subtypes of this organism may infect man. Penicillin, erythromycin, and minocycline were bactericidal agents to all six spirochetes. These in vitro findings may be helpful in determining specific antibiotic treatment of Lyme disease, which was previously based primarily on clinical observations.