title: M protein-associated adherence of Streptococcus pyogenes to epithelial surfaces: prerequisite for virulence.
abstract: Virulent strains of Streptococcus pyogenes containing M protein were found to adhere well to human cheek epithelial cells in vitro, whereas an avirulent M - mutant strain adhered feebly. Pretreatment of M + strains with trypsin to remove their M protein surface coating or reacting them with type-specific antiserum markedly impaired their abilities to attach to epithelial cells. Electron microscopy revealed that the attachment of an M + strain to germfree rat epithelial cells was mediated by a fuzzy surface structure previously shown to contain M protein. When mixtures of streptomycin-resistant M + and M - strains were introduced into the mouths of mice, the proportions of the M + strain increased on tongue and cheek surfaces relative to its M - mutant. These data indicate that the surface fuzz of S. pyogenes which contains M protein functions in the attachment of the organism to epithelial surfaces, thereby permitting its colonization.
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D002448:Cell Adhesion; D002610:Cheek / Q000382:microbiology; D004847:Epithelial Cells; D004848:Epithelium; D005856:Germ-Free Life; D051379:Mice; D008854:Microscopy, Electron; D009055:Mouth / Q000382:microbiology; D013297:Streptococcus pyogenes / Q000472:pathogenicity*; D013997:Time Factors; D014774:Virulence
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins