Guyard C, Chester E, Raffel S, Schrumpf M, Policastro P, Porcella S, et al. Relapsing fever spirochetes contain chromosomal genes with unique direct tandemly repeated sequences. Infect Immun. 2005;73:3025-37 pubmed
..These polymorphic proteins may be involved in the pathogenicity of these relapsing fever spirochetes and provide a mechanism for antigenic heterogeneity within their populations...
Guyard C, Battisti J, Raffel S, Schrumpf M, Whitney A, Krum J, et al. Relapsing fever spirochaetes produce a serine protease that provides resistance to oxidative stress and killing by neutrophils. Mol Microbiol. 2006;60:710-22 pubmed
..This periplasmic enzyme may prevent the accumulation of proteins damaged by the innate immune response and contribute to the ability of the relapsing fever spirochaetes to achieve high cell densities in blood. ..