Identification of genes essential for leptospirosis.

The development of methods for the construction of defined mutants of pathogenic Leptospira has been a breakthrough in the study of leptospiral virulence. These methods have allowed the identification of genes essential for infection in animal models. This chapter describes methods for random transposon mutagenesis of pathogenic leptospires, identification of transposon insertion sites using direct sequencing from genomic DNA and a nested PCR utilizing degenerate oligonucleotides, and methods for testing mutant attenuation in the hamster model of infection.