Characterization of partially purified group B streptococcal clumping factor

Using a strain of group B Streptococci, characteristics of the streptococcal clumping factor was investigated. In contrast to that of Staphylococcus, the streptococcal clumping factor reacted with plasmas from guinea-pig and sheep although staphylococcal clumping factor did not react with them. In addition, streptococcal clumping factor was resistant to heat, sonication, and chemical reagents; it was also degradable by proteolytic enzyme and galactose oxidase. Hydrochloric acid extract of the whole cell was subjected to Sephadex column chromatography and fraction containing streptococcal clumping factor was obtained. This fraction reacted selectively with fibrinogen in human plasma, caused paracoagulation, and the factor was presumed to be an acidic proteinaceous substance.