The ecological plaque hypothesis for the aetiopathogenesis of caries implies a microbial shift towards a more acidogenic and aciduric dental plaque microflora, due to a frequent carbohydrate intake. Certain plaque bacteria exhibit metabolic activity, at a low pH. A correlation exists between the increased numbers of some aciduric bacterial species, e.g. mutans streptococci and lactobacilli, and...

The growth characteristics of Tyzzer's organisms in cultured mouse hepatocytes were examined by direct bacterial counting and plaque assay. The viability of propagated bacteria and time required for the maximum titers depended on incubation time and inoculum dose, respectively. Both infectious titers and bacterial counts at optimum harvests were much higher than those obtained from infected mou...

BACKGROUND Dental caries develops as a result of the metabolism of carbohydrates by cariogenic bacteria present in a complex biofilm. The present study aimed to examine if bacteria in pooled supragingival plaque samples quantified using a "checkerboard DNA-DNA hybridization" based panel of caries-related bacteria, could reflect the caries experience in a manner similar to saliva samples analyse...

A selected group of oral bacteria commonly associated with dental health is capable of producing alkali via the arginine deiminase system (ADS), which has a profound impact on the pH of human oral biofilms. An increased risk for dental caries has been associated with reduced ADS activity of the bacteria in oral biofilms. Arginolytic bacterial strains from dental plaque samples of caries-free an...

Background: T cell activation is discussed as an important factor in the pathogenesis of psoriasis. Recently, a lot of attention has been paid to the role of superantigens in T cell activation in the pathogenesis of psoriasis. In this study, the role of staphylococcal superantigens in the pathogenesis of psoriasis with identification of staphylococcal toxin levels in the skin lesions of p...

OBJECTIVE Epidemiological, biological and clinical links between periodontal and cardiovascular diseases are now well established. Several human studies have detected bacterial DNA corresponding to periodontal pathogens in cardiovascular samples. Intraplaque hemorrhage has been associated with a higher risk of atherosclerotic plaque rupture, potentially mediated by neutrophil activation. In thi...

BACKGROUND To investigate the microbial composition of biofilms at inflamed peri-implant and periodontal tissues in the same subject, using 16S rRNA sequencing. METHODS Supra- and submucosal, and supra- and subgingival plaque samples were collected from 7 subjects suffering from diseased peri-implant and periodontal tissues. Bacterial DNA was isolated and 16S rRNA genes were amplified, sequen...