Distribution and Antigenicity of Fibronectin Binding Proteins (SfbI and SfbII) of <i>Streptococcus pyogenes</i> Clinical Isolates from the Northern Territory, Australia

Abstract

Fibronectin binding proteins play an important role in the adherence and invasion of group A streptococci (GAS). Genotypically distinct GAS isolates were screened for the presence and expression of two streptococcal fibronectin binding protein genes, sfbI and sfbII. Of the tested strains, 64 and 36% were shown to harbor and express the sfbI and sfbII genes, respectively. All sfbII-positive strains tested were also positive for sfbI, but only 28% of the sfbII-negative strains were positive for sfbI. High levels of immunoglobulin G antibodies to both SfbI and SfbII were found in sera from 80 subjects with defined streptococcal infections.