文摘
Spirochetes cause many important diseases in humans and animals, including syphilis, relapsing fever, leptospirosis and Lyme disease. Recent advances in molecular genetics have allowed Koch's molecular postulates to be applied to the study of the virulence factors in these bacteria. Such advances include the use of electroporation, the identification of several antibiotic resistance phenotypes as useful genetic markers, the development of extrachromosomal cloning vectors and the isolation of knockout mutants and their complementation.