RELA and infection: However, bacterial reisolation indicated that the pattern of infection was slightly more complex than first appeared, as the data indicated that the introduction of a functional relA gene to the ΔrelAΔspoT mutant might facilitate some degree of infection even though there were no visible signs of disease, as the ΔrelAΔspoT(relA) complementation strain yielded a bacterial titer of 2.04 × 106 CFU/cm2, which was intermediate between the values for the ΔrelAΔspoT mutant (2.12 × 104 CFU/cm2) and the wild-type isolate (6.51 × 106 CFU/cm2) (Fig. 2B).