FIG 4.

Mouse colonization competitions between response regulator deletion strains and wild type. The competitive index (CI) is shown for competitions with the indicated response regulator deletion. Response regulator deletions were in the strain MP13 (MP1 att_λ::pAS07) and competed against the marked wild-type strain MP7 (MP1 att_λ::pML8). Each symbol represents measurements for a single mouse, taken at least 20 days postinoculation, and the horizontal bars indicate the geometric means. The lower dashed line is the detection limit (10⁻⁴).