Selective increase in hydrogen peroxide resistance of a coagulase-positive staphylococcus.

Staphylococcus culture 105B was serially treated with 0.05% hydrogen peroxide at 54.4 C or without hydrogen peroxide at this temperature to determine changes in resistance to these conditions and in catalase activity of the surviving populations. Resistance of the final surviving populations to H(2)O(2) treatment and to heat treatment without H(2)O(2) was 5.6 and 4.5 times greater, respectively, than the parent culture. Catalase activities of the cell-free extracts of survivors of the H(2)O(2) treatments and of the heat treatments were 33.56 and 2.69 times greater, respectively, than the control. The untreated control cultures grew in Peptonized Milk (Difco), but addition of sodium pyruvate to the medium was necessary to support growth of survivors.