CP and coinfection: In addition to the role for ZnuB in Zn acquisition and resistance to CP in vitro, this protein also contributes to pathogenesis in vivo. Specifically, co-infection with wildtype demonstrates that ΔznuB is less able to compete with wildtype in vivo. Notably, in the lung, ΔznuB exhibits reduced competitive fitness in both wildtype and CP-deficient mice, suggesting that other factors in addition to CP may contribute to Zn limitation within the lung.