Plasmid deficient <i>Yersinia pseudotuberculosis</i> grow and persist in mouse deep tissue sites with little clonal loss.

<p>A) Growth within the spleen (blue diamond) and liver (red square) after IV inoculation of <i>Yptb</i>(P⁻) in C57BL/6 mice. 1×10⁵<i>Yptb</i>(P⁻) were IV inoculated, organs were collected 3 days post-infection, and bacterial numbers were determined by colony forming units (CFU) per organ. N = 3–6 mice, mean CFU is plotted, ± standard deviation. B) Average number of unique transposon insertion clones in the Input library, and per organ over 6 days post IV infection, +/− standard deviation, N = 3.