Comparative colonization of human Actinomyces species in hamsters under different dietary conditions

Oral colonization of hamsters by Actinomyces species of human origin was studied. Strains of A. viscosus and A. naeslundii became implanted while strains of A. israelii, A. odontolyticus and Arachnia propionica did not. A glucose diet was superior to a sucrose diet for A. viscosus and A. naeslundii implantation. A. naeslundii appeared to colonize the animals at a slower rate. Suppression of the oral‐intestinal flora by a short‐term pretreatment of 3–7 days or continuous exposure to dietary streptomycin sulphate also improved implantation of streptomycin‐resistant strains of these 2 species. An experimental period of 3–6 months was required for development of gross deposits of cervical plaque and periodontal pathology.