Interfering alpha-streptococci as a protection against recurrent streptococcal tonsillitis in children.

Recurrent streptococcal tonsillitis/pharyngitis is a great problem, especially in certain epidemiological situations. Patients treated with antibiotics often have a disturbed normal throat flora and may lack, e.g., alpha-streptococci known in vitro to have an interfering activity against group A streptococci. Thirty-one patients with recurrent streptococcal tonsillitis were given antibiotics for 10 days. At the end of this treatment they were sprayed in their mouths with four selected alpha-streptococcal strains known to have strong growth inhibiting activity in vitro against most beta-streptococci group A. The follow-up period after this colonization was 3 months. After alpha-streptococcal treatment, none of the patients attracted a new tonsillitis during the follow-up period while 8% of the controls had a second tonsillitis. Treatment of streptococcal tonsillitis/pharyngitis with antibiotics followed by recolonization with alpha-streptococci seems to hinder further recurrences.