Figure 2. . Percentage recovery units (PRUs: CFUs recovered from nasal wash or lung homogenate divided by CFUs originally used to infect mice and multiplied by 106) for competitive colonization between Streptococcus pneumoniae EF3030 and the Phe/Phe mutant (A), EF3030 and the Phe/Tyr mutant (B), and noncompetitive colonization of EF3030, Phe/Phe, and Phe/Tyr (C). Lines connect data from the same mouse. Bars indicate median PRUs. NP, nasopharynx. p values were calculated by the Wilcoxon matched-pairs signed-rank test (A and B) and the Mann-Whitney unpaired 2-tailed test (C).