Association of coagulase and/or pigmentation with the virulence of a capsule-lacking Staphylococcus aureus in iron-compromised mice.

The effect of pigmentation and coagulase on the virulence of a capsule-lacking Staphylococcus aureus were studied using iron-compromised mice. The presence of either coagulase or pigmentation maintained the viability of this bacterium in the peritoneal cavity. Both coagulase and pigmentation, however, lead not only to maintained viability, but also to its proliferation in the peritoneal macrophages. The iron was found to enhance the virulence of this bacterium, but iron enhancement was contingent on the presence of either pigmentation or coagulase or preferably both.