Transposon Mutagenesis of the Lyme Disease Agent

Borrelia burgdorferi , the causative agent of Lyme disease, is an obligate parasite that cycles between vertebrate hosts and tick vectors. Attempts to understand the genetic factors that allow B. burgdorferi to sense, adapt to, and survive in different environments have been limited by a relatively low transformation rate. Here, we describe a mariner -based transposon system that achieves saturating levels of random mutagenesis in B. burgdorferi . In comparison with allelic exchange, which targets a single locus, transposon mutagenesis can create libraries of mutants encompassing disruptions of all genes. Suitably designed screens or selections of such a library permit the recovery of mutants exhibiting a desired phenotype. The system described here allows rapid identification of the genetic locus responsible for the mutant phenotype. With appropriate modifications, this mariner -based transposon can be adapted to other spirochetes and bacteria with inefficient genetic transformation methods.