Antibacterial Activity of Sodium Citrate against Oral Bacteria Isolated from Human Tongue Dorsum

Antibacterial activity of sodium citrate against tongue bacteria, especially hydrogen-sulfide (H2S) producers, was examined. Based on 16s rDNA partial sequences analysis, 691 isolates from 6 subjects were identified. In the present study, Prevotella histicola, P. melaninogenica, Veillonella atypica and V. dispar/V. parvula were detected as predominant H2S producing bacteria. Antibacterial assay showed that sodium citrate inhibited the growth of the representative strains of H2S producers at low concentrations although it similarly inhibited that of commensal bacteria, viz., Streptococcus parasanguinis and S. salivarius. When the effects of several pH conditions on antibacterial activity of sodium citrate against P. melaninogenica JCM6325T were examined, the activity was effective under neutral pH as well as under acidic conditions.