IgG-Fc-receptors in T-type 12 group A streptococci from clinical specimens: absence from M-type 12 and presence in M-type 22.

Abstract

Eighty-eight T-type 12 group A streptococcal strains were randomly selected from routine specimens in two epidemiologically unrelated districts. All of 26 M-type 12 strains lacked IgA and IgG Fc-receptors, whereas all 32 M-type 22 strains had IgG Fc-receptors and 20 of them also receptors for IgA Fc. The remaining strains were not further M-typed but 18 of these 30 strains exhibited receptors for IgG and 13 for IgA.