Time-lapse confocal microscopy to study in vitro Streptococcus mutans surface colonization.

The cariogenicity of Streptococcus mutans relates to its ability to form biofilms on dental surfaces. The aim of this work was to develop a flowcell system compatible with time-lapse confocal microscopy to compare the adhesion and accumulation of S. mutans cells on surfaces in unsupplemented media against media containing sucrose or sucralose (a non-metabolized sweetener) over a short period of time.

Impact of Polymicrobial Infection on Fitness of Streptococcus gordonii .

Pathogenic microbial ecosystems are often polymicrobial, and interbacterial interactions drive emergent properties of these communities. In the oral cavity, Streptococcus gordonii is a foundational species in the development of plaque biofilms, which can contribute to periodontal disease and, after gaining access to the bloodstream, target remote sites such as heart valves. Here, we used a transposon sequencing (Tn-Seq) library of S.

Vascular Patterning as Integrative Readout of Complex Molecular and Physiological Signaling by VESsel GENeration Analysis.

The molecular signaling cascades that regulate angiogenesis and microvascular remodeling are fundamental to normal development, healthy physiology, and pathologies such as inflammation and cancer. Yet quantifying such complex, fractally branching vascular patterns remains difficult. We review application of NASA's globally available, freely downloadable VESsel GENeration (VESGEN) Analysis software to numerous examples of 2D vascular trees, networks, and tree-network composites.

Bacteria Modify Hypha Formation, Microcolony Properties, and Survival within Macrophages.

Phagocytic cells are crucial components of the innate immune system preventing mucosal infections. and often colonize mucosal sites, along with , and yet interkingdom interactions that might alter the survival and escape of fungi from macrophages are not understood. Murine macrophages were coinfected with or , along with to evaluate changes in fungal survival.

Role of glucosyltransferase R in biofilm interactions between Streptococcus oralis and Candida albicans.

Streptococcal glucosyltransferases (Gtf) synthesize α-glucan exopolymers which contribute to biofilm matrix. Streptococcus oralis interacts with the opportunistic pathogen Candida albicans to form hypervirulent biofilms. S.

Streptococcal peptides that signal Enterococcus faecalis cells carrying the pheromone-responsive conjugative plasmid pAM373.

Pheromone-mediated conjugative transfer of enterococcal plasmids can contribute to the dissemination of genes involved in antibiotic resistance, fitness, and virulence among co-residents of mixed microbial communities. We have previously shown that intergeneric signaling by the Streptococcus gordonii strain Challis heptapeptide s.g.

Streptococcus gordonii pheromone s.g.cAM373 may influence the reservoir of antibiotic resistance determinants of Enterococcus faecalis origin in the oral metagenome.

Streptococcus gordonii produces a pheromone heptapeptide, s.g.cAM373, which induces a conjugative mating response in Enterococcus faecalis cells carrying the responsive plasmid, pAM373.

S. oralis activates the Efg1 filamentation pathway in C. albicans to promote cross-kingdom interactions and mucosal biofilms.

Candida albicans and Streptococcus oralis are ubiquitous oral commensal organisms. Under host-permissive conditions these organisms can form hypervirulent mucosal biofilms. C.

Transcriptome analysis of Streptococcus gordonii Challis DL1 indicates a role for the biofilm-associated fruRBA operon in response to Candida albicans.

Multiple levels of interkingdom signaling have been implicated in maintaining the ecological balance between Candida albicans and commensal streptococci to assure a state of oral health. To better understand the molecular mechanisms involved in the initial streptococcal response to the presence of C. albicans that can initiate oral surface colonization and biofilm formation, hypha-forming cells were incubated with Streptococcus gordonii cells for 30 min to assess the streptococcal transcriptome response.

Codon-optimized fluorescent mTFP and mCherry for microscopic visualization and genetic counterselection of streptococci and enterococci.

Despite the powerful potential of fluorescent proteins for labeling bacteria, their use has been limited in multi-species oral biofilm models. Fermentative metabolism by streptococcal species that initiate biofilm colonization results in an acidic, reduced microenvironment that may limit the activities of some fluorescent proteins which are influenced by pH and oxygen availability. The need to reliably distinguish morphologically similar strains within biofilms was the impetus for this work.

Streptococcus gordonii comCDE (competence) operon modulates biofilm formation with Candida albicans.

Candida albicans is a pleiomorphic fungus that forms mixed species biofilms with Streptococcus gordonii, an early colonizer of oral cavity surfaces. Activation of quorum sensing (QS; intercellular signalling) promotes monospecies biofilm development by these micro-organisms, but the role of QS in mixed species communities is not understood. The comCDE genes in S.

O-mannosylation in Candida albicans enables development of interkingdom biofilm communities.

Candida albicans is a fungus that colonizes oral cavity surfaces, the gut, and the genital tract. Streptococcus gordonii is a ubiquitous oral bacterium that has been shown to form biofilm communities with C. albicans.

Streptococcus gordonii glucosyltransferase promotes biofilm interactions with Candida albicans.

Background: Candida albicans co-aggregates with Streptococcus gordonii to form biofilms and their interactions in mucosal biofilms may lead to pathogenic synergy. Although the functions of glucosyltransferases (Gtf) of Mutans streptococci have been well characterized, the biological roles of these enzymes in commensal oral streptococci, such as S. gordonii, in oral biofilm communities are less clear.

Collagen-binding streptococcal surface proteins influence the susceptibility of biofilm cells to endodontic antimicrobial solutions.

Introduction: Previous studies have indicated that the antimicrobial efficacy of endodontic irrigants may be diminished in the presence of patient tissues and fluids. With Streptococcus gordonii as a model microorganism, we used a genetic approach to investigate the hypothesis that bacterial surface proteins with collagen-binding abilities may function to protect biofilm cells from antiseptics commonly used in root canal treatment.

Methods: S.

Streptococcus gordonii collagen-binding domain protein CbdA may enhance bacterial survival in instrumented root canals ex vivo.

Introduction: The surface-associated collagen-binding protein Ace of Enterococcus faecalis has been implicated as a virulence factor that contributes to bacterial persistence in endodontic infections. The purpose of this study was to determine if proteins with amino acid sequence similarity to Ace found in more abundant oral streptococci could play a similar role in potentially enhancing endodontic infections.

Methods: A Streptococcus gordonii gene similar to ace was identified by genome sequence searches in silico.

Streptococcus mutans out-competes Streptococcus gordonii in vivo.

Streptococcus gordonii and Streptococcus mutans avidly colonize teeth. S. gordonii glucosyltransferase (GtfG) and amylase-binding proteins (AbpA/AbpB), and S.

Molecular analysis of 16S rRNA genes identifies potentially periodontal pathogenic bacteria and archaea in the plaque of partially erupted third molars.

Purpose: Small subunit rRNA sequencing and phylogenetic analysis were used to identify cultivable and uncultivable microorganisms present in the dental plaque of symptomatic and asymptomatic partially erupted third molars to determine the prevalence of putative periodontal pathogens in pericoronal sites.

Materials And Methods: Template DNA prepared from subgingival plaque collected from partially erupted symptomatic and asymptomatic mandibular third molars and healthy incisors was used in polymerase chain reaction with broad-range oligonucleotide primers to amplify 16S rRNA bacterial and archaeal genes. Amplicons were cloned, sequenced, and compared with known nucleotide sequences in online databases to identify the microorganisms present.

Response of fatty acid synthesis genes to the binding of human salivary amylase by Streptococcus gordonii.

Streptococcus gordonii, an important primary colonizer of dental plaque biofilm, specifically binds to salivary amylase via the surface-associated amylase-binding protein A (AbpA). We hypothesized that a function of amylase binding to S. gordonii may be to modulate the expression of chromosomal genes, which could influence bacterial survival and persistence in the oral cavity.

Interaction of Candida albicans cell wall Als3 protein with Streptococcus gordonii SspB adhesin promotes development of mixed-species communities.

Candida albicans colonizes human mucosa and prosthetic surfaces associated with artificial joints, catheters, and dentures. In the oral cavity, C. albicans coexists with numerous bacterial species, and evidence suggests that bacteria may modulate fungal growth and biofilm formation.

Heterologous expression of Candida albicans cell wall-associated adhesins in Saccharomyces cerevisiae Reveals differential specificities in adherence and biofilm formation and in binding oral Streptococcus gordonii.

Colonization and infection of the human host by opportunistic pathogen Candida albicans derive from an ability of this fungus to colonize mucosal tissues and prosthetic devices within the polymicrobial communities present. To determine the functions of C. albicans cell wall proteins in interactions with host or bacterial molecules, Saccharomyces cerevisiae was utilized as a surrogate host to express C.

A genetic determinant in Streptococcus gordonii Challis encodes a peptide with activity similar to that of enterococcal sex pheromone cAM373, which facilitates intergeneric DNA transfer.

Enterococcus faecalis strains secrete multiple peptides representing different sex pheromones that induce mating responses by bacteria carrying specific conjugative plasmids. The pheromone cAM373, which induces a response by the enterococcal plasmid pAM373, has been of interest because a similar activity is also secreted by Streptococcus gordonii and Staphylococcus aureus. The potential to facilitate intergeneric DNA transfer from E.

Human platelets recognize a novel surface protein, PadA, on Streptococcus gordonii through a unique interaction involving fibrinogen receptor GPIIbIIIa.

The concept of an infectious agent playing a role in cardiovascular disease is slowly gaining attention. Among several pathogens identified, the oral bacterium Streptococcus gordonii has been implicated as a plausible agent. Platelet adhesion and subsequent aggregation are critical events in the pathogenesis and dissemination of the infective process.

Oscillation of angiogenesis with vascular dropout in diabetic retinopathy by VESsel GENeration analysis (VESGEN).

Purpose: Vascular dropout and angiogenesis are hallmarks of the progression of diabetic retinopathy (DR). However, current evaluation of DR relies on grading of secondary vascular effects, such as microaneurysms and hemorrhages, by clinical examination instead of by evaluation of actual vascular changes. The purpose of this study was to map and quantify vascular changes during progression of DR by VESsel GENeration Analysis (VESGEN).

Streptococcus gordonii modulates Candida albicans biofilm formation through intergeneric communication.

The fungus Candida albicans colonizes human oral cavity surfaces in conjunction with a complex microflora. C. albicans SC5314 formed biofilms on saliva-coated surfaces that in early stages of development consisted of approximately 30% hyphal forms.

VESGEN 2D: automated, user-interactive software for quantification and mapping of angiogenic and lymphangiogenic trees and networks.

Quantification of microvascular remodeling as a meaningful discovery tool requires mapping and measurement of site-specific changes within vascular trees and networks. Vessel density and other critical vascular parameters are often modulated by molecular regulators as determined by local vascular architecture. For example, enlargement of vessel diameter by vascular endothelial growth factor (VEGF) is restricted to specific generations of vessel branching (Parsons-Wingerter et al.