Figure 8. Effect of nos on S. aureus virulence.

1×10⁸ CFU/ml of UAMS-1 (wild-type) and KR1010 (nos mutant) cultures were each injected into the tail veins of female CD-1 Swiss mice (n = 9 mice per group). The infection proceeded for 7 days, or until mice reached a pre-moribund state (used as a measure of mortality). Mice were then euthanized and organs were collected and stored at −80°C prior to homogenization and determination of recovered CFU/organ. Graphs represent the calculated bacterial burdens for the kidneys (A), heart (B), lungs (C) and liver (D), and the percent survival (E). For A–D, data are graphed as box-whisker plots, indicating the 25^th, median, and 75^th percentiles (box lines), the 90^th and 10^th percentiles (error bars), and mean (+) of each data-set. *denotes statistically significant difference of mortality (p<0.05, Log Rank and Chi Squared Test with 1-degree of freedom), **denotes statistical significance of bacterial recovery (p<0.05, Mann-Whitney Test).