Project description:These LCMS spectra were obtained to elucidate if unique small-molecules are excreted by the bacterial host Actinomyces odintolyticus and its epibiont Candidatus Saccaribacteria oral taxon TM7x while growing in co-culture. Candidatus Saccaribacteria oral taxon TM7x cannot grow by it self in mono-culture.
Project description:To combat dental implant-associated infections, there is a need for novel materials which effectively inhibit bacterial biofilm formation. In the present study, a titanium surface functionalization based on the “slippery liquid-infused porous surfaces” (SLIPS) principle was analyzed in an oral flow chamber system. The immobilized liquid layer was stable over 13 days of continuous flow. With increasing flow rates, the surface exhibited a significant reduction in attached biofilm of both the oral initial colonizer Streptococcus oralis and an oral multi-species biofilm composed of S. oralis, Actinomyces naeslundii, Veillonella dispar and Porphyromonas gingivalis. Using single cell force spectroscopy, reduced bacterial adhesion forces on the lubricant layer could be measured. Gene expression patterns in biofilms on SLIPS, on control surfaces and planktonic cultures were also compared. For this purpose, the genome of S. oralis strain ATCC® 9811TM was sequenced using PacBio Sequel technology. Even though biofilm cells showed clear changes in gene expression compared to planktonic cells, no differences could be detected between bacteria on SLIPS and on control surfaces. Therefore, it can be concluded that the ability of liquid-infused titanium to repel biofilms is solely due to weakened bacterial adhesion to the underlying liquid interface.
Project description:Oral streptococci, including Streptococcus gordonii, and Actinomyces naeslundii, are consistently found to be the most abundant bacteria in the early stages of dental plaque accumulation. These organisms interact physically (coaggregate) in vitro and in vivo. We hypothesized that coaggregation between S. gordonii and A. naeslundii leads to changes in gene expression in the partner organisms. Furthermore, we predicted that coaggregation-induced changes in phenotype contribute to the success of streptococci and actinomyces in dental plaque. To assess the responses of S. gordonii to coaggregation with A. naeslundii, RNA was extracted from S. gordonii cells 3 h after inducing coaggregation with A. naeslundii or from equivalent S. gordonii monocultures. The two RNA populations were reverse transcribed and compared by competitive hybridization with an S. gordonii genomic microarray. The most striking feature of the response to coaggregation was a profound change in expression of S. gordonii genes involved in arginine biosynthesis and transport. Subsequent experiments demonstrated that coaggregation with A. naeslundii stabilizes arginine biosynthesis in S. gordonii and enables growth under low-arginine conditions, such as those present in human saliva. Keywords: Cell-cell interaction
Project description:Background: A growing body of evidence demonstrates a different bacterial composition in the oral cavity of patients with oral lichen planus (OLP). Patients and methods: Buccal swab samples were collected from affected and non-affected sites of six patients with reticular OLP and the healthy oral mucosa of six control subjects. 16S rRNA MiSeq sequencing and mass spectrometry-based proteomics and were utilised to identify the metataxonomic and metaproteomic profiles of the oral microbiome in both groups. Results: The most abundant species in the three subgroups were Streptococcus oralis and Pseudomonas aeruginosa, accounting for up to 70% of the total population. A Canonical Correspondence Analysis showed differential clustering of samples from the healthy and OLP groups. Three species (Veillonella parvula, Actinomyces sp, and Lactococcus lactis) were significantly over-represented in the control group and one (Granulicatella elegans) in patients with OLP. The metaproteomic data revealed that several G. haemolysans-belonging peptidases and other proteins with inflammatory and virulence potential were found present in OLP lesions only. Conclusion: Our data suggest that several bacterial species and peptides are associated with OLP. Future studies with larger cohorts should be conducted to determine their role in the aetiology of OLP and evaluate their potential as disease biomarkers.
Project description:Oryza sativa Japonica Group OsNRAMP6, Similar to (Rice Genome Annotation Project) metal transporter Nramp6, is expressed in 10 baseline experiment(s);