Streptococcal adherence to pharyngeal cells of children with acute rheumatic fever

The adherence of strains of group A Streptococcus to pharyngeal cells from Egyptian children with acute rheumatic fever (RF) was examined. Nine RF-associated and eight unassociated streptococcal strains were tested in vitro for adherence to pharyngeal cells from 11 patients with acute RF and eight normal subjects. RF-associated streptococcal strains adhered more avidly to pharyngeal cells of patients with acute RF (mean, 11.8 bacteria/cell) than did unassociated strains (mean, 5.9 bacteria/cell; P less than 0.05). The difference in mean adherence could be attributed to certain RF-associated strains. There was no significant difference in adherence when pharyngeal cells from controls were used. Furthermore, one RF-associated streptococcal strain was found to adhere considerably more avidly to pharyngeal cells of patients with RF than to those of controls.