Fig 1.
Contribution of S. aureus coa, vwb and clfA to formation of rabbit abscesses.
(A) Average abscess volume for rabbits infected subcutaneously with S. aureus Newman wild-type (WT) or isogenic mutant strains as indicated. The volume of 10 abscesses per bacterial strain was measured daily following inoculation. (B) Individual abscesses plotted for selected days are depicted in panel A. (C) A separate set of 2 animals (4 abscesses/strain) was used to determine S. aureus CFU per abscess on day 2 post-infection and (D) the volume of rabbit abscesses. Each symbol represents a data point obtained from a single abscess. P values were calculated using a one-way ANOVA and Dunnett’s post-test.
Table 1.
Contribution of coa, vwb and clfA to structure and development of the abscess.
Fig 2.
Histopathology of rabbit skin abscess caused by S. aureus.
Histopathology sections represent skin abscesses caused by S. aureus Newman WT (A, B), ΔclfA (C, D) or Δcoa/Δvwb (E, F) strains on day 10 post-infection. Abscess sections were stained with standard Masson’s trichrome stain to enhance fine structure detail of muscle tissues, collagen fibers and fibrin. (A, C and E) original magnification is 20×. (B, D, and F) 200× magnification of selected area (black rectangle) depicted in panels A, C or E.
Fig 3.
Fibrin deposition in rabbit skin abscess caused by S. aureus Newman.
Representative sections of rabbit skin abscesses on Day 2 (A, D, G, K, N), Day 6 (B, E, H, L, O) and Day 10 (C, F, J, M, P) post infection. Abscesses from rabbits infected with S. aureus Newman WT (A-C), ΔclfA (D-F), Δcoa (G-J), Δvwb (K-M) and Δcoa/Δvwb (N-P). Tissue sections were stained with Mallory’s phosphotungstic acid-hematoxylin stain for visualization of fibrin (black arrows). Magnification is 200×. Inset image is the abscess at 20× (black rectangle).
Fig 4.
Vasculitis caused by S. aureus Newman WT.
Histopathology sections of rabbit abscesses depicting vascular necrosis caused by S. aureus Newman WT (A), and an intact artery within a Δcoa/Δvwb induced abscess (B) or PBS control (C) on day 10 post infection. Original magnification is 100×.
Fig 5.
S. aureus Newman causes increased production of proinflammatory molecules in human whole blood.
S. aureus was cultured in human heparinized blood for 2 h. Accumulation of proinflammatory molecules in plasma was evaluated by quantitative, multiplexed immunoassays (HumanMAP v2.0; Myriad RBM) as described in Materials and Methods section. Data represents average of 3 donors with one-way ANOVA and Tukey’s post-test used to determine statistical significance. *P < 0.05 for the selected pairs; # p < 0.05 compared to uninfected blood sample (ctrl).