[Human fibrinogen binding activities in culture supernates of group A streptococci. Streptococcal Diseases Study Group].

ABSTRACT

Fibrinogen binding activities in culture supernates of group A streptococci were detected by dot blot assay using horseradish peroxidase conjugated human fibrinogen. Various intensities in colored dots were seen in 63 of 70 strains isolated from pharyngitis patients in 1992. Strong binding activities in all of 16 strains were partially sensitive to trypsin digestion. The binding activities in the concentrated culture supernate of M-type 4 strain SS91 were analysed by SDS-PAGE and Western blotting. Intense colored bands and faint ones were seen in the position corresponding to 89K, 66K, 59K, 49K, 42KDa and 77K, 53K, 51K, 44KDa, respectively. Only one band at 42KDa remained after trypsin digestion.