Receptors for fibrinogen and aggregated beta 2-microglobulin detected in strains of group B streptococci

Abstract

Binding of radiolabeled human fibrinogen and aggregated beta-microglobulin was measured in 60 strains of beta-hemolytic group B streptococci. Positive fibrinogen binding was detected in seven of the strains. Six of the group B strains showed an uptake of aggregated beta 2-microglobulin. Four individual strains carried both receptors, indicating a positive correlation between their occurrence. Inhibition studies showed that fibrinogen competed sterically with beta 2-microglobulin binding. Receptors for both proteins were trypsin sensitive. The presence of receptors did not correlate with the serological type of the 49 group B strains tested. However, all seven type II strains were negative. No uptake of fibrinogen was noted in any of 40 group D strains tested. Binding structures for fibrinogen and aggregated beta 2-microglobulin detected in group B streptococci were similar to receptors for the same proteins in group A, C, and G streptococci in terms of mutual correlation and steric interference of binding. The occasional occurrence of these receptors also in group B strains might reflect a common origin of some types of surface proteins in gram-positive cocci.

Binding of oral streptococci to human fibrinogen

“…Different strains bound variable amount of fibrinogen. Such strain variability in binding of streptococci to fibrinogen has been described previously (20, 39, 49). In fibrinogen binding among the eight oral species examined, S. mitis , S. oralis , most S. sanguinis and all strains of S. gordonii were positive and all strains of mutans group streptococci were negative.…”

“…Fibrinogen binding to streptococci has previously been described (20, 39, 49). Fibrinogen binds to a wide variety of streptococcal strains from groups A, B, C, and G (20, 39), but the binding has not been fully characterized. We examined the ability of S. gordonii strain DL1 to bind immobilized human fibrinogen.…”

A fibrinogen receptor from group B Streptococcus interacts with fibrinogen by repetitive units with novel ligand binding sites

“…The presence of fibrinogen‐binding structures on the surface of GBS has been recognized for several years (Schönbeck et al ., 1981; Lämmler et al ., 1983; Chhatwal et al ., 1985). However, the present study is the first to describe the molecular basis of fibrinogen binding in GBS.…”

“…The interaction of GBS with human fibrinogen has been demonstrated in several studies (Schönbeck et al ., 1981;Lämmler et al ., 1983; Chhatwal et al ., 1985; Spellerberg et al. , 2002).…”

Surgical Peritonitis: Its Relevance to the Pathogenesis of Peritonitis in CAPD

“…Although fibrin exudation may have evolved as an effective local bacterial trap it seems likely that some strains of pathogenic bacteria have developed an effective response to this segment of the host defense system. The precursor molecule of fibrin, fibrinogen, has been shown to possess binding structures for some gram-positive pathogenic bacteria (32)(33)(34). Fibrinogen binds to a wide variety of Streptococcal strains from groups A, B, C, and G, while binding to S. aureus is rapid, partially reversible, and saturable.…”