INTERFERENCE OF ALPHA-HEMOLYTIC STREPTOCOCCI ISOLATED FROM TONSILLAR SURFACE ON BETA-HEMOLYTIC STREPTOCOCCI (STREPTOCOCCUS-PYOGENES) - A METHODOLOGICAL STUDY

  • 1 January 1983
    • journal article
    • research article
    • Vol. 254  (4) , 459-468
Abstract
The interference between .alpha.-hemolytic streptococci obtained from patients with chronic tonsillitis and group A streptococci was studied. For this purpose, 3 in vitro methods were designed and compared. The results obtained by a simple plating technique suitable for screening correlated well with those using more laborous techniques. Some of the .alpha.-hemolytic and .beta.-hemolytic streptococci combinations were tested in vivo using a tissue cage model in rabbits, which allowed repeated sampling. In most instances, agreement between in vitro and in vivo methods was observed. Several .alpha.-hemolytic strains had inhibitory capacity vs. group A streptococci belonging to different serotypes; other .alpha.-hemolytic strains had inhibitory activity restricted to group A streptococci within a certain serotype. .beta.-Hemolytic strains with growth inhibiting activity vs. some .alpha.-hemolytic strains were found. The activity was most likely due to bacteriocin-like substances.