Generating knock-out and complementation strains of Neisseria meningitidis

The human-restricted pathogens Neisseria meningitidis and Neisseria gonorrhoeae are naturally competent for DNA uptake. This trait has been exploited extensively for genetic manipulation of these bacteria in the laboratory. Most transformation protocols were developed for N. gonorrhoeae, but appear to work also for N. meningitidis. In this chapter, we describe a number of protocols for genetic manipulation of N. meningitidis. Specifically, we describe how to (1) obtain knock-out mutants containing antibiotic-resistance markers, (2) generate markerless knock-out mutants, and (3) construct complementation strains. The generation of such mutants provides a valuable resource for studies of bacterial pathogenesis and vaccine development.