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:Oral tongue squamous cell carcinomas (OTSCC) are a homogenous group of aggressive tumors in the head and neck region, with a rising incidence among younger population. The role of altered DNA methylation in OTSCC and its link with clinical parameters has not been fully assessed yet. We performed genome-wide methylation analysis of oral tongue primary tumors (n = 52) using 485, 512 probes and correlated altered methylation with differences in gene expression. We used an ensemble machine-learning algorithm to identify differentially methylated probes and regions predictive of survival, risk habits, nodal status, tumor stage, and HPV infection followed by validation using data from the cancer genome atlas (TCGA) project on oral tongue (n = 24) and tumors from all subsites of head and neck region (n = 50).
Project description:Oral tongue squamous cell carcinomas (OTSCC) are a homogenous group of aggressive tumors in the head and neck region, with a rising incidence among younger population. The role of altered DNA methylation in OTSCC and its link with clinical parameters has not been fully assessed yet. We performed genome-wide methylation analysis of oral tongue primary tumors (n = 52) using 485, 512 probes and correlated altered methylation with differences in gene expression. We used an ensemble machine-learning algorithm to identify differentially methylated probes and regions predictive of survival, risk habits, nodal status, tumor stage, and HPV infection followed by validation using data from the cancer genome atlas (TCGA) project on oral tongue (n = 24) and tumors from all subsites of head and neck region (n = 50).
Project description:Oral tongue squamous cell carcinomas (OTSCC) are a homogenous group of aggressive tumors in the head and neck region, with a rising incidence among younger population. The role of altered DNA methylation in OTSCC and its link with clinical parameters has not been fully assessed yet. We performed genome-wide methylation analysis of oral tongue primary tumors (n = 52) using 485, 512 probes and correlated altered methylation with differences in gene expression. We used an ensemble machine-learning algorithm to identify differentially methylated probes and regions predictive of survival, risk habits, nodal status, tumor stage, and HPV infection followed by validation using data from the cancer genome atlas (TCGA) project on oral tongue (n = 24) and tumors from all subsites of head and neck region (n = 50).