(A), (B), (C), (D), (E), (F); Gastrointestinal (GI) co-colonization levels by P. aeruginosa strains in individual mice 5 days after being given a mixture of one epidemic strain (LES or C3719) and one non-epidemic strain (PAO1, PA14 or PA2192nm) (n = 8 mice per each combination of strains). Colonization levels achieved by the epidemic strains were higher than those by the non-epidemic strains ((A), (B), (C), (D), (E), * P<0.05 by Wilcoxon signed rank test) except for one combination of strains C3719 and PAO1 (F).
(G), Competitive Indices (C.I.) of GI co-colonization levels by epidemic versus non-epidemic strains in each mouse in the different groups. C.I. was defined as the colonization level of an epidemic strain divided by the level of a non-epidemic strain. A C.I. above 1.0 indicates the epidemic strain out-competed the non-epidemic strain in the co-colonization level. Horizontal bars indicate median, error bars indicate interquartile range.