Experimentally induced infection by oral anaerobic microorganisms in a mouse model.

A mouse model was developed to study the abscessogenic potential of pure and mixed cultures of oral anaerobes associated with infections of endodontic origin. Maximum subcutaneous lesions were seen on their backs between 3 and 14 d after inoculation. Strains of Fusobacterium nucleatum, Peptostreptococcus anaerobius, and Veillonella parvula were pathogenic in pure culture. A mixed culture of F. nucleatum with either Porphyromonas gingivalis or Prevotella intermedia was significantly more pathogenic than F. nucleatum in pure culture. Histopathological examination of tissue sections from control mice injected with India ink in the medium demonstrated a pathway of particulate migration from the backs of the mice to their abdomen.