[Phenomenon of erythrocyte "spreading" on the surface of agar caused by hemolytic staphylococci]

Hemolytic staphylococcus was incubated at 37 degrees C in a Petri dish, on meat-peptone agar with a layer of erythrocytes on its surface. Colonies surrounded by smaller radially-located secondary colonies of the same staphylococcus were revealed in 24 hours; there proved to be a direct relationship between the hemolytic activity of the staphylococcus and the size of the zone of erythrocyte "spreading". This phenomenon called the erythrocyte "spreading" phenomenon was caused only by hemolytic staphylococci. Apparently hemolytic staphylococcus secreted surfactants causing the "spreading" of erythrocytes from the growing colony.