No abstract

No abstract

Aggregatibacter actinomycetemcomitans is usually isolated from the oral cavity where it is associated with active periodontitis. The species can be divided into six serotypes (a-f) according to their surface carbohydrate antigens. However, some clinical isolates cannot be grouped within these six serotypes. Gram-negative, facultative anaerobic, catalase-positive coccobacilli were isolated from a patient with periodontitis and identified by employing genetic, biochemical and serological analyses. Phenotypic data identified the isolate as A. actinomycetemcomitans. Serotype-specific polysaccharide antigen from the isolate was untypeable by immunodiffusion testing in comparison with reference A. actinomycetemcomitans serotype a to f strains. Biofilm formation by the isolate was strong but cytotoxic activity was low. Gas chromatography/mass spectroscopy analysis of partially methylated alditol acetates from surface polysaccharide showed the presence of 2,4-di-O-methyl-rhamnose and 2,3,6-tri-O-methyl-glucose, with a 1 : 1 m ratio. The (1)H- and (13)C-nuclear magnetic resonance spectra of the antigen showed that both constituent glycoses had alpha-anomeric configuration. It is proposed that the untyped strain is a new A. actinomycetemcomitans serotype, designated serotype g.

Caries experience was statistically significantly related to the presence of all three microbes under study, both in dental plaque and saliva.

No abstract

The new selective medium, AASM, was highly selective for A. actinomycetemcomitans, eliminated possible false-positive results and was useful for the isolation of A. actinomycetemcomitans from clinical samples.

No abstract

Among the genus Rothia, R. dentocariosa and R. mucilaginosa have been isolated from the human oral cavity. Currently, we reported that new selective media were developed for the isolation of each species. The clinical efficacy of the genus Rothia was evaluated from samples of oral cavities, such as pit and fissure plaque, buccal surface plaque, the buccal membrane surface, the dorsum of tongue, gingival crevicular fluid (GCF), and the mucosal surface of denture base using these selective media. R. dentocariosa and R. mucilaginosa were detected in all sites from pit and fissure plaque, buccal surface plaque, the buccal membrane surface and the dorsum of tongue. Therefore, both Rothia species are common members of oral cavity. R. mucilaginosa was predominant at the dorsum of tongue with 28.15% to total streptococci. Results show that the dorsum of tongue is the main habitation area of R. mucilaginosa. R. dentocariosa and R. mucilaginosa were also detected in GCF.These bacteria were detected to a certain extent on the mucosal surface of denture base.Therefore, it seems that these bacteria are members of denture plaque.