YACs are stably confined macrophage surface structures.

<p>RAW macrophages were infected for 60 minutes with GFP-expressing wild-type (pYV) or plasmid-cured (pΔYV) <i>Y</i>. <i>pseudotuberculosis</i>. pHrodo was then added to the infected cells for 40 minutes and were then analyzed as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0133298#pone.0133298.g003" target="_blank">Fig 3</a> and what is presented is representative of multiple experiments. The arrows in the middle row images indicates a YPIII/pYV bacterium that is intensely positive for pHrodo*. Plotted to the right is the corresponding fluorescence of individual macrophage-associated bacteria. (N >40 each condition; * <i>P</i> < 0.05 using student <i>t</i>-test)