Plasmids containing a putative in vivo induced promoter cloned upstream from cre gene were extracted from resolved strain to be introduced in the unresolved Lox2 (or Lox2ΔG) strain. Resolution rate was measured after 15 generations of in vitro growth or after in vivo persistence by calculating the percentage of EmS, CmR and TetR CFU. Values correspond to the mean of three measurements obtained after independent experiments. Error bars indicate standard deviations. A Student test was used to determine the following P values when comparing in vitro resolution to in vivo induction: for Pivi1, nd; for Pivi2, 0.009; for Pivi3, 0.017; for Pivi4, 0.043; for Pivi5, 0.008; for Pivi6, 0.007; and for Pivi7, 0.646. All promoters indicated by an asterisk are significantly induced during in vivo persistence (*, p≤0.05; **, p≤0.001).