FACTORS AFFECTING THE SENSITIZATION OF SHEEP ERYTHROCYTES TO STAPHYLOCOCCAL BETA LYSIN

Abstract

It is well known that the beta hemolysin of Staphylococcus aureus is unable to cause lysis of erythrocytes at 37 °C but will do so when the temperature is lowered. Sheep erythrocytes sensitized to partially purified beta lysin were, however, lysed at 37 °C by NaCl at concentrations less but not greater than 0.80–0.85%. Increasing acidity rather than increasing alkalinity was also effective in causing lysis of erythrocytes at this temperature. These observations suggest that the beta lysin-sensitized red cells are much more sensitive to osmotic swelling than are normal cells.Kinetic studies of the effect of time, lysin concentration, pH, and temperature on sensitization of sheep erythrocytes to beta lysin indicate that the reaction may be enzymatic. This concept is further supported by the Mg++ ion requirement of the beta lysin and its sensitivity to the action of trypsin.