Fig. 2.

Reversion of WalK(S221P) in VISA XN108 contributed to bacterial dissemination. (A) Dissemination of XN108 and XN108-R in organs of the infected mice. BALB/c mice (n = 7 in each group) were challenged via tail vein injection with 5 × 10⁷ CFU of the pGFP plasmid-transformed S. aureus XN108 and XN108-R, respectively. The infected mice were sacrificed on 5 d pi and their organs were isolated. The radiant efficiency of the murine organs was determined using the IVIS® Lumina LT system. The organs of the PBS-injected mice served as negative control. (B) Bacterial burdens in organs of the infected mice. After radiant efficiency determination, the kidney and liver of the infected mice were grinded to homogenate and bacteria in the tissue homogenates were counted by plate dilution method. Statistical significance was calculated by Student’s t-test. * P < 0.05 and ns represents no significance. (C) Detection of the levels of proinflammatory cytokines. Sera and organs (i.e., liver and kidney) of the XN108-pGFP-, XN108-R-pGFP-infected, and PBS-injected mice (n = 3 for each group) were respectively collected on 5 d pi, and the levels of IL-6, IL-1β, and TNF-α in the sera and organ homogenates were determined by ELISA as described in Materials and methods. Statistical significance was calculated by 2way ANOVA. ** P < 0.01, *** P < 0.001, and ns represents no significance.