Hypersensitivity in Guinea Pigs to Oral Fusospirochetal Organisms

¹ Department of Microbiology, University of Texas Dental Branch, Houston, Texas

Guinea pigs either infected or sensitized with a fusospirochetal exudate antigen demonstrated a dermal response to an inoculation of a cell-free extract prepared from the exudate. The reaction was enhanced when adjuvant was used or with repeated infectious challenges. This response appears to reflect the presence of both the anaphylactic and the tuberculin type of hypersensitivity in the sensitized animals. The dermal response was differentiated from the Shwartzman reaction and was passively transferred with lymphoid and splenic cells. Guinea pigs sensitized with whole exudate antigen and guinea pigs challenged with infectious fusospirochetal exudate are more sensitive to an extract of B. melaninogenicus than to extracts of two fusobacteria, an actinomycete, a vibrio, an anaerobic streptococcus, and an anaerobic Gram-negative bacillus. It is suggested that hypersensitivity may alter the host-parasite relationship in periodontal disease.