[Atypical forms of Borrelia burgdorferi--clinical consequences].

Borrelia burgdorferi utilizes a variety of mechanisms to counteract eradication by its host and establish chronic infection. We discuss several of these mechanisms, including plasmid encoded genes, morphologic variants, cysts formation, colonies formation, antigenic variation, and resistance to iron deprivation. These mechanisms, as well as the possible survival of Borrelia burgdorferi in forms with low metabolic activity, may explain relapsing Lyme disease, and may, also account for the difficulties with eradicating this pathogen.