Calcium oxide and magnesium oxide inhibit plasma coagulation by Staphylococcus aureus cells at the lower concentration than zinc oxide. 
We examined the effect of ceramic powder slurries on the coagulation of plasma by Staphylococcus aureus cells.  Plasma coagulation by S. aureus strains or their cultured supernatant was inhibited in the plasma with 0.12% calcium oxide or 0.25% magnesium oxide after incubation for 24 h at 37 degrees C. Inhibition of plasma coagulation by calcium oxide and magnesium oxide was observed at the lower concentration than zinc oxide.