Parameters Affecting the Adherence and Tissue Tropisms of Streptococcus pyogenes

Virulent M protein-containing strains of Streptococcus pyogenes were found to adhere well to human pharyngeal cells in vitro. In contrast, an avirulent M - strain and an enteropathogenic Escherichia coli strain adhered feebly. When various rat tissues were exposed to mixtures of a virulent S. pyogenes strain and an enteropathogenic E. coli strain, the relative proportions of the two pathogenic strains recovered from mucosal surfaces differed among the sites studied. S. pyogenes cells were found to adhere in higher proportions than enteropathogenic E. coli cells to the mucosal surfaces of rat tongues, whereas on surfaces of the urinary bladder, their affinities were reversed. The data indicate that bacterial adherence is influenced by the specificity of both the bacterial and epithelial surfaces, and they suggest that adherence may influence the tissue tropisms of pathogens. Early stationary-phase cells of S. pyogenes attached better to epithelial cells than did bacteria in other growth phases. The adherence of S. pyogenes cells was impaired by pretreatment with trypsin, wheat germ lipase, Tween 80, Triton X-100, sodium lauryl sulfate, heat at 56 C, anti-group A antiserum, the presence of phospholipids, and preincubation of the epithelial cells with Streptococcus salivarius cell walls. Altering the pH or treatment with ethylenediaminetetraacetic acid had no effect on the ability of S. pyogenes cells to adhere.