ABSCESS-FORMING FACTOR(S) PRODUCED BY STAPHYLOCOCCUS AUREUS. II. ABSCESS FORMATION AND IMMUNITY BY A STAPHYLOCOCCUS AND ITS MUTANTS.

Lam, Gow T. (Jefferson Medical College, Philadelphia, Pa.), Francis J. Sweeney, Jr., Charlotte M. Witmer, and Robert I. Wise. Abscess-forming factor(s) produced by Staphylococcus aureus. II. Abscess formation and immunity by a Staphylococcus and its mutants. J. Bacteriol. 86:87-91. 1963.-Three mutants were derived from a virulent parent strain of Staphylococcus aureus by ultraviolet irradiation. One mutant retained coagulase but lost its hemolytic activity; a second had no coagulase but retained its hemolysin; and a third contained hemolysin and bound coagulase but no free coagulase. The parent strain was coagulase-positive, hemolysin-positive, and possessed all the known extracellular products. All four strains were compared by bacteriophage typing, mannitol utilization, and antibiotic sensitivity tests. The four isolates were studied for their pathogenicity in Swiss albino mice and four strains of inbred mice. Their immunological characteristics as studied by repeated subcutaneous injections are reported. The importance of hemolysin and the coagulase in abscess formation is discussed. Local immunity was produced only by the parent strain, but abscesses were produced by all the strains containing coagulase.