Michod et al.[16] have reviewed evidence that RecA-mediated transformation is an adaptation for homologous recombinational repair of DNA damage in B. subtilis, as well as in several other bacterial species (i.e. Neisseria gonorrhoeae, Hemophilus influenzae, Streptococcus pneumoniae, Streptococcus mutans and Helicobacter pylori). In the case of the pathogenic species that infect humans, it was proposed that RecA-mediated repair of DNA damages may be of substantial benefit when these bacteria are challenged by the oxidative defenses of their host.