A tissue culture procedure is described which permits the quantitative evaluation of the intracellular survival of staphylococci within leucocytes. Staphylococcus aureus survived, but did not multiply, within neutrophils and monocytes of normal rabbits. The same was true of normal human blood leucocytes. Staphylococcus albus on the other hand was destroyed by these cells under the same conditions. Rat monocytes destroyed S. aureus and S. albus with equal facility. Although most experiments were carried out in the presence of 50 µg. streptomycin/ml., similar results were obtained without the use of this antibiotic.
The applications of the tissue culture procedure with regard to studies on virulence and immunity in staphylococcal disease are discussed.