Structural and molecular basis of the role of starch and sucrose in Streptococcus mutans biofilms development
Ontology highlight
ABSTRACT:
ORGANISM(S): Streptococcus mutans UA159
SUBMITTER: Marlise Klein
PROVIDER: E-GEOD-21872 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:Transcriptional profiling to investigate the response of Streptococcus mutans biofilms to starch and sucrose at distinct stages of biofilm development. RNA was extracted and purified from four replicate samples of each biofilm sample of interest and labeled with Cy3. For each replicate, labeled RNA was hybridized to slides along with Cy5-labeled reference RNA, extracted from S. mutans UA159 cells grown to mid-log.
2010-05-15 | E-GEOD-21831 | biostudies-arrayexpress
Project description:The aim of this study is to evaluate the evolutionary robustness of the quorum sensing inhibitor (QSI) furanone C-30 for the treatment of P. aeruginosa biofilm infections. We repeatedly exposed P. aeruginosa biofilms to furanone C-30 (with or without tobramycin) in the synthetic cystic fibrosis sputum medium (SCFM2) and characterized the genotype and phenotype of the evolved lineages. P. aeruginosa biofilms were grown in SCFM2 for 24 h after which the treatment in fresh SCFM2 was added to obtain a final concentration of 20 µg/ml tobramycin and 100 µg/ml furanone C-30. The negative control was treated with fresh SCFM2, including the same amount of DMSO (0.25%) as for the biofilms treated with C-30. After 24 h of static incubation at 37°C, biofilms were sonicated and vortexed in order to disintegrate the biofilm aggregates. After each cycle the number of CFU was determined and an aliquot of the culture was stored at -80°C in Microbank vials to allow further tests on the evolved strains. A sample from the treated biofilm was used to prepare a new overnight culture, in order to start a new cycle. For each treatment three independent lineages were established, that were each exposed for 16 cycles. Whole-genome sequencing was performed on the wild type P. aeruginosa PAO1 and on the exposed lineages after 5, 10 and 16 cycles.
2021-03-05 | E-MTAB-10124 | biostudies-arrayexpress
Project description:The lesions of enamel caries can be considered as the outcome of dysbiotic changes in the biofilm community of supragingival dental plaque. Demineralization occurs as the cumulative outcome of repeated shifts towards a less diverse microbiota that produces and tolerates a low pH environment in tooth sites that are sheltered from protective factors in host saliva. Although the etiology of caries is multifactorial, frequent consumption of foods rich in fermentable carbohydrates, notably sucrose, appears to be one of the major factors driving the microbiota in the direction of dysbiosis, particularly in the case of otherwise healthy children with normal salivary flow. Streptococcus mutans and closely related species (such as Streptococcus sobrinus) have long been considered to play a primary etiological role in dental caries. S. mutans responds to sucrose by producing large quantities of lactic acid. It is very tolerant of low pH, and produces an insoluble extracellular polysaccharide that may sequester acid at tooth surfaces. The mechanisms behind those putative virulence factors have been intensively studied in monoculture, and recently in simple multi-species consortia. Much less is known of other species that may also contribute to or protect against dysbiosis driven by dietary carbohydrates. Some strains of “non-mutans” streptococci produce and tolerate acid at levels comparable to S. mutans, while others show increased ariginolytic capabilities, which may act to raise pH within the biofilm matrix. S. mutans tends to be a minority species even in caries-active children, and carious lesions likewise can occur in children with no detectable S. mutans. 16S rDNA-based metagenomic comparisons of caries-active and caries-free subjects have detected associations between caries and a variety of oral species, including not only non-mutans streptococci, but also members of other genera, such as Scardovia and Bifidobacterium. Caries associations have not been consistent between studies. Moreover, different taxonomic clusters have been defined as subgroups within the same study. This raises an important point. Although caries-associated communities are typically less diverse than healthy supragingival plaque overall, those dysbiotic communities still display considerable taxonomic diversity between affected individuals. That in turn raises the question of whether it is desirable to define biomarkers of dysbiosis that are less dependent on taxonomy. The Human Microbiome project generated comprehensive metagenomic data for a wide variety of body sites in healthy subjects, including supragingival plaque. Although most of that data was based on 16S rDNA sequencing, shotgun metagenomics was also used to catalog the functional potential of all microbial genes within a smaller subset of subjects. One of the key findings was that healthy sites from different people were broadly similar with respect to their functional profiles, even though there was extensive individual variation in their taxonomic profiles. It is possible that the “conservation of function” concept may also extend to dysbiotic communities. This would explain why microbial communities associated with caries still show considerable taxonomic variation. In that case, differential patterns of community-wide gene and/or protein expression might provide a more accurate indicator of dysbiosis than can be achieved by counting caries-associated species. Metatranscriptomic or metaproteomic approaches can be used to provide information on function. A recent metatranscriptomic comparison of subgingival plaque from healthy and periodontally diseased sites in three subjects has provided data that support the “conservation of function” concept. They observed that taxonomically diverse diseased sites shared conserved gene expression profiles [20]. By the same token, a recent metaproteomic comparison of gut microbiotas from healthy controls to Crohn’s disease patients found that major shifts in protein expression by function did not always correlate with changes in taxon relative abundance [21]. In this metaproteomic study, we found that sucrose–induced changes in protein expression patterns for pathways involving glycolysis, lactate production, aciduricity and ammonia/glutamate metabolism were likewise conserved in taxonomically diverse dysbiotic oral microcosm biofilm communities.
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Project description:S. aureus biofilms are associated with the organism's ability to cause disease. Biofilm associated bacteria must cope with the host's innate immune system. We used commercially available Affymetrix S. aureus GeneChips to compare the gene expression properties of 4 and 6 day established biofilms following short (1 hr)- and long (24 hr)- term exposure to macrophages and neutrophils. S. aureus strain USA300 LAC biofilms where formed for 4 or 6 days. Established biofilms were then exposed to macrophages for 1 or 24 hr. Alternatively, biofilms were exposed to neutrophils for 1 or 4 hr. Total bacterial RNA was isolated and subjected to GeneChip hybridization and analysis. We sought to determine the regulatory effects of Macrophages and Neutrophils on established S. aureus biofilms.
2013-12-01 | E-GEOD-50675 | biostudies-arrayexpress
Project description:Pseudomonas aeruginosa biofilms were dispersed spontaneously, with 18 mM glutamate, 500 uM SNP, by stopping the flow for 1 hour and restarting it or via vapor nanobubbles.
2020-08-28 | E-MTAB-8354 | biostudies-arrayexpress
Project description:The physiological and transcriptional response of Nitrosomonas europaea biofilms to phenol and toluene was examined and compared to suspended cells. Biofilms were grown in Drip Flow Biofilm Reactors under continuous flow conditions of growth medium containing ammonia as growth substrate. The responses of N. europaea biofilms to the aromatic hydrocarbons phenol and toluene were determined during short-term (3 h) additions of each compound to the biofilms. Ammonia oxidation in the biofilms was inhibited 50% by 60 uM phenol and 100 uM toluene. These concentrations were chosen for microarray analysis of phenol- and toluene-exposed N. europaea biofilms. Liquid batch cultures of exponentially growing N. europaea cells were harvested alongside the biofilms to determine differential gene expression between attached and suspended growth of N. europaea. Four sample groups of N. europaea cells were used in this study, with biological triplicates of each group. Groups were: Control (untreated) biofilms, phenol-exposed biofilms, toluene-exposed biofilms, and exponentially growing suspended cells. Biofilms were grown in Drip Flow Biofilm Reactors containing 4 independent growth channels and subject to 2 hour inhibition tests. During each experiment, 2 biofilm channels served as control with no inhibitor present and the other 2 biofilm channels were exposed to either 60 uM phenol or 100 uM toluene. Nitrite production was monitored throughout the experiment, and the given concentrations of phenol and toluene resulted in 50% inhibition of ammonia oxidation by the biofilms. Suspended cells were grown in batch reactors. Three 4-plex NimbleGen microarray chips were used, and each chip contained one sample from each experimental group. QC of samples was determined by spectrophotometric methods and using Agilent bioanalyzer traces to determine purity and integrity of RNA and cDNA. A sample tracking report was used to verify the correct hybridization of each sample to the intended array.
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2016-08-19 | E-GEOD-85787 | biostudies-arrayexpress