INTRACELLULAR RESERVOIR OF STREPTOCOCCUS-PYOGENES IN-VIVO - A POSSIBLE EXPLANATION FOR RECURRENT PHARYNGOTONSILLITIS

Numerous theories have been presented that attempt to explain the freq uent recurrences of pharyngotonsillitis caused by Streptococcus pyogen es; these recurrences occur after seemingly adequate antibiotic treatm ent. We previously have demonstrated that S pyogenes can survive for u p to 7 days intracellularly in immortalized human respiratory epitheli al cells grown in an antibiotic supplemented medium. Viable S pyogenes were externalized, and established an extracellular infection, whenev er the extracellular antibiotic was removed, We have investigated the presence of intracellular S pyogenes in two in vivo studies using resp iratory epithelial cells collected from patients with tonsillitis and the tonsils of asymptomatic carriers. Electron microscopy and immunohi stochemistry demonstrated intracellular S pyogenes in pharyngeal epith elial cells in 13 of 14 patients with tonsillitis (93%). Furthermore, intracellular S pyogenes were found in macrophage-like cells in eight (73%) and in epithelial cells in four (36%) tonsils from 11 asymptomat ic S pyogenes carriers, These in vivo data strongly support the hypoth esis that intracellular S pyogenes can constitute a reservoir of bacte ria with the potential to cause reinfections.