FIGURE 1: Working model for how commensal Neisseria DNA kills Neisseria gonorrhoeae on the human mucosa (see text for details). Top left: commensal Neisseria cells on a mucosal passage. Top right: Neisseria gonorrhoeae arriving in the vicinity of the commensal biofilm. Middle: cutaway showing commensal DNA entering a Neisseria gonorrhoeae cell, RecA-mediated recombination of this DNA with the pathogen chromosome, restriction enzyme cleavage of the synaptic joint, and loss of chromosome integrity and cell death. Keys to the figures are in the bottom panel.