Figure 4From: The Yersinia YopE and YopH type III effector proteins enhance bacterial proliferation following contact with eukaryotic cellsViability assessment of Y. pseudotuberculosis by vital staining. (A) Various combinations of live and isopropanol-killed Y. pseudotuberculosis were mixed, stained with SYTO 9 and propidium iodide, and analyzed by flow cytometry. Shown in the left column are the light-scattering plots of cultures containing either 100% live bacteria (top), 100% killed bacteria (bottom), or an equal mixture of live and dead bacteria (middle). The histograms shown to the right of each light-scattering plot are the corresponding signals in the FL1 (green channel) of the R1-gated events. The Medium fluorescence intensity of the events within the Ml region were 184 (top) 99 (middle) and 30 (bottom). (B) RAW cells were infected with either the wild-type (top) or yopB (bottom) strains at a MOI of 20 for 2 hours following which the bacteria were recovered, stained with SYTO 9/propidium iodide, and analyzed and presented as in (A). The percentages of the events falling in either the lower left (11) or upper right (ur) quadrants in the light-scattering plots were 36% (11) and 42% (ur) for the wild type and 43% (11) and 37% (ur) for yopB. In parenthesis is shown the medium fluorescence intensity of the events within the M1 region.Back to article page