LCT and infection: Histological scores were comparable except for higher lung inflammation in Δpsmα (P = .04) and Δpsmαβhld (P = .01) than LAC-WT infections (Fig 2B), while mean (±SD) lung bacterial densities were comparable for the three groups (2.31 ± 1.04, 2.21 ± 0.39 vs. 2.03 ± 1.18 log10 CFUs/g, respectively; NS).