The Action of Fibrinogen on certain Pathogenic Cocci

Summary: The properties of the material responsible for the clumping reaction given by suspensions of coagulase-positive staphylococci when shaken in the presence of fibrinogen were examined and a possible mechanism is suggested for the reaction. Of other bacteria examined only streptococci of groups A, C and G absorbed fibrinogen, and of these relatively few gave clumping, though the cell material responsible for absorption was similar to that found in staphylococci. In staphylococci it is believed that a single substance is responsible for both absorption and clumping, and its properties suggest a peptide complex. The possible usefulness of coagulase-positive cocci in the detection of minute amounts of fibrinogen is indicated.