Enumeration, isolation, and species identification of mycoplasmas in saliva sampled from the normal and pathological human oral cavity and antibody response to an oral mycoplasma (Mycoplasma salivarium)

Abstract

Saliva samples collected from 393 subjects with and without oral diseases were examined for concentrations of mycoplasmas and Mycoplasma species. Mycoplasmas were isolated from 383 (97%) of the 393 subjects. Viable counts ranged from zero to 7.6 X 10(7) CFU/ml (median, 6.9 X 10(4)) and were significantly (P less than 0.01) higher in diseased subjects, except for those with arthrosis temporomandibularis, than in controls. Of 1,400 isolates, 897 (64%), 442 (30%), and 8 (1%) were identified as Mycoplasma salivarium, M. orale, and M. hominis, respectively, and the remaining 73 isolates (5%) were unidentifiable. More than two-thirds of the isolates from diseased subjects versus only half from controls were identified as M. salivarium. In diseased subjects other than those with ostitis (especially those with arthrosis temporomandibularis), the incidence of M. salivarium was higher than that of M. orale, whereas the former occurred about as frequently as the latter in the controls. Antibodies to M. salivarium were also measured in sera from some subjects by the metabolism inhibition test. Sera with metabolism inhibition titers of 16 or greater were rated positive. There was no significant difference in the prevalence of antibodies between diseased subjects (60%) and controls (40%), but the mean titers (97 to 220) of all positive sera from diseased subjects were two to four times those for sera from controls. In addition, a fourfold or greater rise or fall of antibody titers to the organism was shown in paired sera from some subjects. On the basis of these results, M. salivarium was strongly suggested to participate etiologically in some cases of oral infection.