Species In Saliva Research Articles

Distribution and Isolation Frequency of Eight Streptococcal Species in Saliva from Predentate and Dentate Children and Adults

The isolation frequency and distribution of eight recently defined streptococcal species have been investigated in the saliva of adults and that of both predentate and dentate children. The effects of frequency of sugar intake and tooth presence on the distribution of streptococcal species were also analyzed. Saliva samples were collected from 121 subjects divided into three study groups: (a) 56 predentate children (predentate group), (b) 37 dentate children (dentate group), and (c) 28 adults (adult group). Up to 17 biochemical and enzymatic tests were used to categorize streptococcal isolates into S. mitis, S. oralis, S. salivarius, S. anginosus, S. sanguis, S. vestibularis, S. mutans, and S. gordonii. The mean total and streptococcal salivary colony-forming units (CFU) were lowest in the predentate group and highest in the adult group. Streptococci were found in all the study subjects, and there was no obvious relationship between the total or streptococcal CFU and the number of teeth or the frequency of sugar intake. There was a wide variation in the isolation frequency of streptococcal species in the three study groups. S. mitis, S. oralis, and S. salivarius were the most frequent species isolated, and together they comprised 83% of the total streptococcal isolates. In contrast to studies using older classifications, S. sanguis was a minor species in the saliva though found more often in adults than in children (p < 0.04). S. anginosus was a minor species found in about 10% of adults and children. S. gordonii was detected rarely and only in dentate subjects. S. mutans was detected only in dentate subjects, significantly greater in adults (57.1%) than in children (5.4%, p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Fluoride in saliva and plaque following use of fluoride-containing mouthwashes.

The sensitivity of methodology for measuring the concentration of fluorine species in saliva and in plaque has been tested. Human subjects mouth-rinsed daily with aqueous solutions of NaF and Na2FPO3. Samples of unstimulated whole saliva and of plaque were collected twice weekly at least 18 hr after treatment application. Oral fluoride concentrations rose from placebo values for approximately two weeks before attaining equilibrium and returned to baseline when daily mouthrinsing was stopped. Mean elevated oral fluoride concentrations increased significantly with increasing applied NaF concentration in the range 0-1000 ppm F (0-0.053 mol/L). There appeared to be a linear relationship between saliva and plaque fluoride. The ability of fluoride treatments to sustain elevated oral fluoride levels between daily applications may be of major importance in caries control.

The molecular basis of the heterogeneity of the gamma subunit of 7 S nerve growth factor.

The arginine esteropeptidase gamma subunit of the 7 S nerve growth factor complex contains six different molecular species which arise by post-translational modifications. An endopeptidase cleavage of the larger of the two peptide chains in two-chain gamma species produces the three-chain species and introduces a new COOH-terminal lysine residue. The charge heterogeneity of the various species arises from the removal, by a carboxypeptidase B-like enzyme in the submaxillary gland, of this lysine residue and/or the original COOH-terminal arginine residue of the shorter Mr = 10,000 chain. These latter interconversions of the gamma species have been reproduced in vitro using carboxypeptidase B. The significant decrease in the proportion of two-chain gamma species in saliva compared to submaxillary gamma subunit suggests that the endopeptidase cleavage can occur during secretion of saliva; however, the subcellular localization of the enzyme has not been ascertained.