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To evaluate the in vitro abilities of probiotic bacteria derived from consumer products to coaggregate with caries-associated mutans streptococci.Six lactobacillus strains (L. acidophilus (CCUG 5917), L. plantarum 299v, L. rhamnosus GG and LB21, L. paracasei F19, L. reuteri PTA5289) were cultivated under anaerobic conditions at 37°C in Man Rogosa Sharpe (MSB) broth for 24 h. Four strains of human streptococci (S. mutans Ingbritt, S. mutans (ATCC 25175), S. mutans GS-5, S. sobrinus (ATCC 33478) were similarly grown in Brain Heart Infusion (BHI) broth. A gastrointestinal pathogen (Escherichia coli) was aerobically cultivated on BHI broth as a positive control. After incubation, the bacteria were aerobically harvested, washed, and suspended in 10 mmol/l phosphate-buffered saline (pH 7.2). The probiotic strains were characterized with the API 50 CH system to confirm their identity. Coaggregation was determined by spectrophotometry in mixtures and bacterial suspensions alone after 1, 2, 4, and 24 h and expressed as the aggregation ratio (%).All probiotic strains showed coaggregation abilities with the oral pathogens and the results were strain specific and dependent on time. S. mutans GS-5 exhibited a significantly higher ability to coaggregate with all the probiotic strains than the other mutans streptococci and E. coli. The differences among the probiotic strains were modest with L. acidophilus being the most prone and L. rhamnosus LB21 the least prone to coaggregate with the oral streptococci.The results demonstrated different abilities of lactobacilli-derived probiotic bacteria to coaggregate with selected oral streptococci. Aggregation assays may be a useful complement for screening of probiotic candidates with possible anti-caries properties.

Longo Vital® herbal tablets have been shown to have a protective effect against periodontal bone loss in rats. This may be ascribed either to a previously demonstrated immuno-stimulatory effect of the tablets, to an antimicrobial effect of the herbs or to a combination of both. In the present study the in vitro susceptibility of 12 dental plaque bacteria to six individual herbs included in Longo Vital® was determined by a broth dilution method. Paprika, rosemary leaves and peppermint inhibited two thirds of the tested bacteria at 2.8-45 mg/ml, 0.75-12 mg/ml and 3-24 mg/ml corresponding to 0.8-12.5 per cent, 1.6-25 per cent and 12.5-100 per cent of the recommended daily dose, respectively. A combination of paprika and rosemary leaves tested towards five susceptible bacteria revealed a decreased inhibitory effect on two of these bacteria, especially of Actinobacillus actinomycetemcomitans to paprika, but conversely a pronounced increase in susceptibility of Peptostreptococcus anaerobius, Porphyromonas gingivalis and Prevotella intermedia now susceptible to 0.01-0.70 mg/ml of each herb, corresponding to 0.02-0.2 per cent of the recommended daily dose. The active ingredients of the herbs, however, and the concentrations of these obtained in blood and periodontal tissues after ingestion of Longo Vital® are not known.

The purpose of the present study was to determine the surface hydrophobicity of small oral spirochetes and to receive an impression of the molecular organization of the cell surfaces. Nine spirochete strains with one endoflagellum from each cell-end (1:2:1 spirochetes) and eight with two endoflagella from each cell-end (2:4:2 spirochetes) from subgingival plaque were examined. Two hydrophobicity assay systems were used: 1) two-phase partitioning and 2) salting-out aggregation by ammonium sulfate. The influence of heat, enzymes, saliva, and serum were examined. The 2:4:2 spirochetes were significantly more hydrophobic than the 1:2:1 spirochetes. For all strains heat treatment increased surface hydrophobicity, whereas incubation with proteases decreased surface hydrophobicity for the 1:2:1 spirochetes. The 2:4:2 spirochetes were unaffected by the proteases. Lipase and hyaluronidase affected the two morphotypes in opposite directions. Saliva did not affect the surface hydrophobicity of any of the strains, whereas rabbit serum decreased this property for the 2:4:2 strains.

Background and objective : The microbial profiles of stimulated saliva samples have been shown to differentiate between patients with periodontitis, patients with dental caries, and orally healthy individuals. Saliva was stimulated to allow for easy and rapid collection; however, microbial composition may not reflect the more natural, unstimulated state. The purpose of this study was to validate whether stimulated saliva is an adequate surrogate for unstimulated saliva in determining salivary microbiomes. Design : Unstimulated ( n =20) and stimulated ( n =20) saliva samples were collected from 20 orally and systemically healthy, non-smoking participants. Salivary bacterial profiles were analyzed by means of the Human Oral Microbe Identification using Next Generation Sequencing (HOMI NGS ), and statistical analysis was performed using Mann–Whitney test with Benjamini–Hochberg’s correction for multiple comparison, cluster analysis, principal component analysis, and correspondence analysis. Results : From a total of 40 saliva samples, 496 probe targets were identified with a mean number of targets per sample of 203 (range: 146–303), and a mean number of probe targets of 206 and 200 in unstimulated and stimulated saliva samples, respectively ( p =0.62). Based on all statistical methods used for this study, the microbial profiles of unstimulated and stimulated saliva samples collected from the same person were not statistically significantly different. Conclusions : Analysis of bacterial salivary profiles in unstimulated and stimulated saliva samples collected from the same individual showed comparable results. Thus, the results verify that stimulated saliva is an adequate surrogate of unstimulated saliva for microbiome-related studies. Keywords: saliva; HOMI NGS; bacteria (Published: 16 March 2016) Citation: Journal of Oral Microbiology 2016, 8: 30112 - http://dx.doi.org/10.3402/jom.v8.30112

Thirty-eight young adults participated in the study. They were divided in a caries-inactive group, a low caries activity group and a moderate to high caries activity group. Total cultivable bacteria, Streptococcus salivarius, and S. mutans in plaque and saliva were quantitated on TSA, MS, and MSB plates, respectively. Sucrase activity was determined by measuring reducing sugars in plaque and saliva after incubation with sucrose. alpha-Amylase activity was determined by Pharmacia Phadebas Amylase test. The data were analyzed with the non-parametric Mann-Whitney U test. The only significant difference was observed for plaque alpha-amylase activity between the caries-inactive group and the moderate-high caries activity group (P less than 0.05). The lack of differences concerning the other variables is discussed mainly on the basis of the multifactorial character of dental caries and the possible insufficiency of the applied methods.