Fig 1. S. aureus stimulates bone resorption and expression of osteoclastic and osteoclastogenic genes in organ cultures of neonatal mouse parietal bones.

(A-C) S. aureus time- and concentration-dependently increased ⁴⁵Ca and CTX release from the parietal bones. (D) The stimulatory effect by S. aureus (3x10⁶ CFU/ml) on CTX release was inhibited by zoledronic acid (0.2 μmol/l). (E, F) S. aureus (3x10⁶ CFU/ml) time-dependently upregulated the mRNA expression of Ctsk and Acp5 in the parietal bones. (G, H) Concentration-dependent effects by S. aureus on Ctsk and Acp mRNA expression in the parietal bones. Data are means of 6 (A-D) or 5 (E-H) observations and SEM is given as vertical bars when larger than the radius of the symbol. In Fig 1A, all effects at 48 h and later were statistically significant (P<0.001) with the exception of S. aureus Tox at 96 h (P<0.01); at 24 h effects were also significant (P<0.05). In Fig 1B, effects by 3x10⁶–3x10⁷ CFU/ml were statistically significant (P>0.01). In Fig 1G, effects were statistically significant at 10⁶ (P<0.01) and 3x10⁶–3x10⁷ (P<0.001) CFU/ml. In Fig 1H, effects by 10⁶–3x10⁷ CFU/ml were statistically significant (P<0.001). ***P<0.001 compared to unstimulated control (C, D) or to S. aureus stimulated bones (D).