Figure 1.

(A) Krona visualization of all bacteria detected across all mice tested. (B) Principal component analysis (PCA) of the fecal microbiota from young-adult and old C57BL/6 mice infected with Listeria monocytogenes (Lm) after 7-days post infection. The clustering on two PCA plots show control (uninfected) versus L. monocytogenes infected mice. Each symbol represents one mouse. Principal component analysis scores are plotted based on the relative abundance of total microbiota. Proportion of variance in each principal coordinate axis is denoted in the corresponding axis label. The uninfected control (brown circle) and infected mice (green circle) show clear separation. (C) Alpha diversity comparisons based on CHAO1. Listeria infection in old mice significantly lowers microbial richness compared with the uninfected old control mice.