The feasibility of immunizing monkeys with enzymes from oral streptococci in an attempt to reduce dental caries was investigated. Forty rhesus monkeys, Macaca mulatta, were used. Cariogenic streptococci, S mutans, were implanted into all the monkeys' mouths. There was no pathological effect resulting from immunization. Of the 40 animals, 30 retained the implanted flora throughout the experiment; the remaining 10 were reimplanted until the streptococci remained. In six months, gross carious lesions were evident with plaque. Inhibitors present in the monkey sera after immunization inhibited glucosyltransferase, fructosyltransferase, and neuraminidase activzties. It was presumed the inhibitors were antibodies. There was a reduction of 68.6% in the total carious lesions in the animals immunized intraorally with glucosyltransferase, 62.4% reduction in those injected with fructosyltransferase, and 57.4% reduction in total lesions in those immunized with glycosidic hydro lases after 19 months, as compared to the control group. There were no gross lesions apparent in the group immunized with glycosidic hydrolases. It appears that immunization with enzymes significantly reduces caries and is feasible in a primate model.
Leishmania infantum-induced primary and challenge infections in rhesus monkeys (Macaca mulatta): a primate model for visceral leishmaniasis
