In vitro competition experiments with SSuT and cured SSuT strains with mixtures of susceptible (black bars), progenitor SSuT (white bars), and passaged parent SSuT (gray bars) strains. CI = (X − Y)/(X + Y); when values approach +1, strains listed on the x axis dominate (*, dominant strains significantly >0; one-sample t test, P < 0.05). When CI is 0, there is an equal proportion of the competing resistance patterns.