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.