Fig 6.

Competitive colonization between parent strains and isogenic mutants to validate genes identified in transposon insertion screens. Mice were treated with 5 days of vancomycin prior to gavage with 1:1 mixtures of marked parent strain (hygromycin resistance cassette at the Tn7 site) and isogenic mutant [substitution of open reading frame with apramycin resistance cassette (A–N) or an unmarked in-frame deletion (O–Q)] of the target gene(s). n = 10 for A–G and L–N. n ≥ 9 for H–K and O–Q. Asterisks denote significance by one-sample t-tests with Dunn correction where *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001, and “ns” indicates not significant. Limit of detection was a competitive index of 10⁻⁷ for A–N and 10⁻³ for O–Q, denoted with a dotted line. Log(competitive index) = 0 or equal recovered CFU of parental strain and mutant is marked with a dashed line.