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European Journal of Case Reports in... 2021is part of the normal flora of the oropharyngeal, nasal, gastrointestinal and genitourinary tracts. Classically, it shows low pathogenicity and virulence, but can very...
UNLABELLED
is part of the normal flora of the oropharyngeal, nasal, gastrointestinal and genitourinary tracts. Classically, it shows low pathogenicity and virulence, but can very rarely cause meningitis in patients who have undergone dental procedures and have poor oral hygiene. The purpose of this report is to highlight the importance of considering as a cause of meningitis in patients with poor oral hygiene. A 53-year-old man was admitted to the emergency department with high fever (39.4°C), headache and drowsiness. His mouth was unhygienic. He was diagnosed with meningitis and empiric antibiotics (ceftriaxone plus ampicillin) and dexamethasone were started. was isolated from cerebrospinal fluid. Ampicillin and dexamethasone were stopped, while ceftriaxone was continued with full recovery of the patient.
LEARNING POINTS
Viridans streptococci such as can rarely cause meningitis as well as endocarditis in patients with poor dental hygiene.Streptococcus viridans meningitis responds well to empiric antibiotic therapy.Patients with any form of streptococcus viridans infection should be screened for endocarditis.
PubMed: 34123936
DOI: 10.12890/2021_002349 -
Applied and Environmental Microbiology Oct 2021Cell-cell adhesion between oral bacteria plays a key role in the development of polymicrobial communities such as dental plaque. Oral streptococci such as Streptococcus...
Cell-cell adhesion between oral bacteria plays a key role in the development of polymicrobial communities such as dental plaque. Oral streptococci such as Streptococcus gordonii and Streptococcus oralis are important early colonizers of dental plaque and bind to a wide range of different oral microorganisms, forming multispecies clumps or "coaggregates." S. gordonii actively responds to coaggregation by regulating gene expression. To further understand these responses, we assessed gene regulation in S. gordonii and S. oralis following coaggregation in 25% human saliva. Coaggregates were formed by mixing, and after 30 min, RNA was extracted for dual transcriptome sequencing (RNA-Seq) analysis. In S. oralis, 18 genes (6 upregulated and 12 downregulated) were regulated by coaggregation. Significantly downregulated genes encoded functions such as amino acid and antibiotic biosynthesis, ribosome, and central carbon metabolism. In total, 28 genes were differentially regulated in Streptococcus gordonii (25 upregulated and 3 downregulated). Many genes associated with transporters and a two-component (NisK/SpaK) regulatory system were upregulated following coaggregation. Our comparative analyses of S. gordoniiS. oralis with different previously published S. gordonii pairings (S. gordoniiFusobacterium nucleatum and S. gordoniiVeillonella parvula) suggest that the gene regulation is specific to each pairing, and responses do not appear to be conserved. This ability to distinguish between neighboring bacteria may be important for S. gordonii to adapt appropriately during the development of complex biofilms such as dental plaque. Dental plaque is responsible for two of the most prevalent diseases in humans, dental caries and periodontitis. Controlling the formation of dental plaque and preventing the transition from oral health to disease requires a detailed understanding of microbial colonization and biofilm development. Streptococci are among the most common colonizers of dental plaque. This study identifies key genes that are regulated when oral streptococci bind to one another, as they do in the early stages of dental plaque formation. We show that specific genes are regulated in two different oral streptococci following the formation of mixed-species aggregates. The specific responses of S. gordonii to coaggregation with S. oralis are different from those to coaggregation with other oral bacteria. Targeting the key genes that are upregulated during interspecies interactions may be a powerful approach to control the development of biofilm and maintain oral health.
Topics: Dental Plaque; Humans; RNA-Seq; Streptococcus gordonii; Streptococcus oralis; Transcriptome
PubMed: 34469191
DOI: 10.1128/AEM.01558-21 -
MSphere Dec 2021As common commensals residing on mucosal tissues, species are known to promote health, while some Streptococcus species act to enhance the pathogenicity of other...
As common commensals residing on mucosal tissues, species are known to promote health, while some Streptococcus species act to enhance the pathogenicity of other organisms in those environments. In this study, we used a combination of imaging of live biofilms and computational modeling to explore biofilm interactions between Streptococcus oralis, an accessory pathogen in oral candidiasis, and Lactobacillus paracasei, an organism with known probiotic properties. A computational agent-based model was created where the two species interact only by competing for space, oxygen and glucose. Quantification of bacterial growth in live biofilms indicated that S. oralis biomass and cell numbers were much lower than predicted by the model. Two subsequent models were then created to examine more complex interactions between these species, one where secretes a surfactant, and another where secretes an inhibitor of S. oralis growth. We observed that the growth of S. oralis could be affected by both mechanisms. Further biofilm experiments support the hypothesis that may secrete an inhibitor of S. oralis growth, although they do not exclude that a surfactant could also be involved. This contribution shows how agent-based modeling and experiments can be used in synergy to address multiple species biofilm interactions, with important roles in mucosal health and disease. We previously discovered a role of the oral commensal Streptococcus oralis as an accessory pathogen. S. oralis increases the virulence of Candida albicans infections in murine oral candidiasis and epithelial cell models through mechanisms which promote the formation of tissue-damaging biofilms. species have known inhibitory effects on biofilm formation of many microbes, including Streptococcus species. Agent-based modeling has great advantages as a means of exploring multifaceted relationships between organisms in complex environments such as biofilms. Here, we used an iterative collaborative process between experimentation and modeling to reveal aspects of the mostly unexplored relationship between S. oralis and in biofilm growth. The inhibitory nature of on S. oralis in biofilms may be exploited as a means of preventing or alleviating mucosal fungal infections.
Topics: Biofilms; Lacticaseibacillus paracasei; Streptococcus oralis; Systems Analysis; Virulence
PubMed: 34908459
DOI: 10.1128/mSphere.00875-21 -
MSphere Feb 2021Lipoteichoic acid (LTA) is a Gram-positive bacterial cell surface polymer that participates in host-microbe interactions. It was previously reported that the major human...
Lipoteichoic acid (LTA) is a Gram-positive bacterial cell surface polymer that participates in host-microbe interactions. It was previously reported that the major human pathogen and the closely related oral commensals and produce type IV LTAs. Herein, using liquid chromatography/mass spectrometry-based lipidomic analysis, we found that in addition to type IV LTA biosynthetic precursors, , , and also produce glycerophosphate (Gro-P)-linked dihexosyl (DH)-diacylglycerol (DAG), which is a biosynthetic precursor of type I LTA. and mutants produce DHDAG but lack (Gro-P)-DHDAG, indicating that the Gro-P moiety is derived from phosphatidylglycerol (PG), whose biosynthesis requires these genes. , but not or , encodes an ortholog of the PG-dependent type I LTA synthase, By heterologous expression analyses, we confirmed that confers poly(Gro-P) synthesis in both and and that can rescue the growth defect of an mutant. However, we do not detect a poly(Gro-P) polymer in using an anti-type I LTA antibody. Moreover, Gro-P-linked DHDAG is still synthesized by an mutant, demonstrating that LtaS does not catalyze Gro-P transfer to DHDAG. Finally, an mutant has increased sensitivity to human serum, demonstrating that confers a beneficial but currently undefined function in Overall, our results demonstrate that , , and produce a Gro-P-linked glycolipid via a PG-dependent, -independent mechanism. The cell wall is a critical structural component of bacterial cells that confers important physiological functions. For pathogens, it is a site of host-pathogen interactions. In this work, we analyze the glycolipids synthesized by the mitis group streptococcal species, , , and We find that all produce the glycolipid, glycerophosphate (Gro-P)-linked dihexosyl (DH)-diacylglycerol (DAG), which is a precursor for the cell wall polymer type I lipoteichoic acid in other bacteria. We investigate whether the known enzyme for type I LTA synthesis, LtaS, plays a role in synthesizing this molecule in Our results indicate that a novel mechanism is responsible. Our results are significant because they identify a novel feature of , , and glycolipid biology.
Topics: Glycerophosphates; Glycolipids; Lipopolysaccharides; Phosphatidylglycerols; Streptococcus mitis; Streptococcus oralis; Streptococcus pneumoniae; Teichoic Acids
PubMed: 33627509
DOI: 10.1128/mSphere.01099-20 -
Scientific Reports Aug 2022Dysbiosis of the oral microbiota plays an important role in the progression of periodontitis, which is characterized by chronic inflammation and alveolar bone loss, and...
Dysbiosis of the oral microbiota plays an important role in the progression of periodontitis, which is characterized by chronic inflammation and alveolar bone loss, and associated with systemic diseases. Bacterial extracellular vesicles (EVs) contain various bioactive molecules and show diverse effects on host environments depending on the bacterial species. Recently, we reported that EVs derived from Filifactor alocis, a Gram-positive periodontal pathogen, had osteoclastogenic activity. In the present study, we analysed the osteoclastogenic potency and immunostimulatory activity of EVs derived from the Gram-negative periodontal pathogens Porphyromonas gingivalis and Tannerella forsythia, the oral commensal bacterium Streptococcus oralis, and the gut probiotic strain Lactobacillus reuteri. Bacterial EVs were purified by density gradient ultracentrifugation using OptiPrep (iodixanol) reagent. EVs from P. gingivalis, T. forsythia, and S. oralis increased osteoclast differentiation and osteoclstogenic cytokine expression in osteoclast precursors, whereas EVs from L. reuteri did not. EVs from P. gingivalis, T. forsythia, and S. oralis preferentially activated Toll-like receptor 2 (TLR2) rather than TLR4 or TLR9, and induced osteoclastogenesis mainly through TLR2. The osteoclastogenic effects of EVs from P. gingivalis and T. forsythia were reduced by both lipoprotein lipase and polymyxin B, an inhibitor of lipopolysaccharide (LPS), while the osteoclastogenic effects of EVs from S. oralis were reduced by lipoprotein lipase alone. These results demonstrate that EVs from periodontal pathogens and oral commensal have osteoclastogenic activity through TLR2 activation by lipoproteins and/or LPS.
Topics: Cell Differentiation; Extracellular Vesicles; Lipopolysaccharides; Lipoprotein Lipase; Microbiota; Mouth; Osteoclasts; Porphyromonas gingivalis; Toll-Like Receptor 2; Toll-Like Receptor 4
PubMed: 35987920
DOI: 10.1038/s41598-022-18412-4 -
Journal of Materials Science. Materials... Sep 2020The aim of this study was to evaluate the interaction between Streptococcus oralis and Polyetheretherketone (PEEK), a novel material recently introduced in implantology....
The aim of this study was to evaluate the interaction between Streptococcus oralis and Polyetheretherketone (PEEK), a novel material recently introduced in implantology. The topographical characterization and the Streptococcus oralis adhesion on this material were compared with other titanium surfaces, currently used for the production of dental implants: machined and double etched (DAE). The superficial micro-roughness of the PEEK discs was analyzed by scanning electron microscopy (SEM) and, the Energy Dispersive Spectrometer (EDS) analyzed their chemical composition. Atomic Force Microscopy (AFM) was used to characterize the micro-topography and the sessile method to evaluate the wettability of the samples. Microbiological analysis measured the colony forming units (CFUs), the biomass (OD detection) and the cell viability after 24 and 48 h after Streptococcus oralis cultivation on the different discs, that were previously incubated with saliva. Results showed that PEEK was characterized by a micro-roughness that was similar to machined titanium but at nano-level the nano-roughness was significantly higher in respect to the other samples. The EDS showed that PEEK superficial composition was characterized mainly by Carbonium and Oxygen. The hydrophilicity and wetting properties of PEEK were similar to machined titanium; on the contrary, double etched discs (DAE) samples were characterized by significantly higher levels (p < 0.05). PEEK was characterized by significant lower CFUs, biomass and viable cells in respect to the titanium surfaces. No differences were found between machined and DAE. The anti-adhesive and antibacterial properties showed by PEEK at 24 and 48 h against a pioneer such as S. oralis, could have an important role in the prevention of all pathologies connected with biofilm formation, like peri-implantitis in dentistry or prosthetic failures in orthopedics.
Topics: Anti-Bacterial Agents; Bacterial Adhesion; Benzophenones; Biomass; Carbon; Cell Survival; Dental Implants; Female; Humans; Hydrophobic and Hydrophilic Interactions; Male; Materials Testing; Microscopy, Atomic Force; Microscopy, Electron, Scanning; Oxygen; Polymers; Prosthesis Design; Prosthesis Failure; Saliva; Stem Cells; Streptococcus oralis; Surface Properties; Titanium; Wettability
PubMed: 32989624
DOI: 10.1007/s10856-020-06408-3 -
Microorganisms May 2022Periodontitis and peri-implantitis are inflammatory conditions with a high global prevalence. Oral pathogens such as play a crucial role in the development of dysbiotic...
Periodontitis and peri-implantitis are inflammatory conditions with a high global prevalence. Oral pathogens such as play a crucial role in the development of dysbiotic biofilms associated with both diseases. The aim of our study was to identify plant-derived substances which mainly inhibit the growth of "disease promoting bacteria", by comparing the effect of root extract against and the commensal species . Antiplanktonic activity was determined by measuring optical density and metabolic activity. Antibiofilm activity was quantified using metabolic activity assays and live/dead fluorescence staining combined with confocal laser scanning microscopy. At concentrations of 3.9 mg/L, root extract selectively inhibited planktonic growth of the oral pathogen , while not inhibiting growth of . Selective effects also occurred in mature biofilms, as was significantly more stressed and inhibited than . Our studies show that low concentrations of root extract specifically inhibit growth, and offer a promising approach for the development of a potential topical agent to prevent alterations in the microbiome due to overgrowth of pathogenic .
PubMed: 35630409
DOI: 10.3390/microorganisms10050965 -
Virulence 2015Streptococcus tigurinus is a novel species of viridans streptococci, shown to cause severe invasive infections such as infective endocarditis, spondylodiscitis and... (Review)
Review
Streptococcus tigurinus is a novel species of viridans streptococci, shown to cause severe invasive infections such as infective endocarditis, spondylodiscitis and meningitis. S. tigurinus belongs to the Streptococcus mitis group and is most closely related to Streptococcus mitis, Streptococcus oralis, Streptococcus pneumoniae, Streptococcus pseudopneumoniae and Streptococcus infantis. The presence of S. tigurinus in the human oral cavity has been documented, including in patients with periodontal disease. This review addresses the available scientific knowledge on S. tigurinus and its association with closely related streptococci, and discusses its putative involvement in common oral infections. While there is as yet no strong evidence on the involvement of S. tigurinus with oral infections, its presence in the oral cavity and its association with endocarditis warrants special attention for a link between oral and systemic infection.
Topics: DNA, Bacterial; Endocarditis, Bacterial; Humans; Microbiota; Mouth; Periodontal Diseases; Periodontitis; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Streptococcal Infections; Streptococcus; Streptococcus mitis
PubMed: 25483862
DOI: 10.4161/21505594.2014.970472 -
MSphere Apr 2023As common commensals residing on mucosal tissues, species are known to promote health, while some Streptococcus species act to enhance the pathogenicity of other...
As common commensals residing on mucosal tissues, species are known to promote health, while some Streptococcus species act to enhance the pathogenicity of other organisms in those environments. In this study we used a combination of imaging of live biofilms and computational modeling to explore biofilm interactions between Streptococcus oralis, an accessory pathogen in oral candidiasis, and Lactobacillus paracasei, an organism with known probiotic properties. A computational agent-based model was created where the two species interact only by competing for space, oxygen, and glucose. Quantification of bacterial growth in live biofilms indicated that S. oralis biomass and cell numbers were much lower than predicted by the model. Two subsequent models were then created to examine more complex interactions between these species, one where secretes a surfactant and another where secretes an inhibitor of S. oralis growth. We observed that the growth of S. oralis could be affected by both mechanisms. Further biofilm experiments support the hypothesis that may secrete an inhibitor of S. oralis growth, although they do not exclude that a surfactant could also be involved. This contribution shows how agent-based modeling and experiments can be used in synergy to address multiple-species biofilm interactions, with important roles in mucosal health and disease. We previously discovered a role of the oral commensal Streptococcus oralis as an accessory pathogen. S. oralis increases the virulence of Candida albicans infections in murine oral candidiasis and epithelial cell models through mechanisms which promote the formation of tissue-damaging biofilms. species have known inhibitory effects on biofilm formation of many microbes, including Streptococcus species. Agent-based modeling has great advantages as a means of exploring multifaceted relationships between organisms in complex environments such as biofilms. Here, we used an iterative collaborative process between experimentation and modeling to reveal aspects of the mostly unexplored relationship between S. oralis and in biofilm growth. The inhibitory nature of on S. oralis in biofilms may be exploited as a means of preventing or alleviating mucosal fungal infections.
PubMed: 36942961
DOI: 10.1128/msphere.00656-22 -
Genomics Sep 2020Streptococcus oralis is an early colonizer bacterium in dental plaques and is considered a potential pathogen of infective endocarditis (IE) disease. In this study, we... (Comparative Study)
Comparative Study
Streptococcus oralis is an early colonizer bacterium in dental plaques and is considered a potential pathogen of infective endocarditis (IE) disease. In this study, we built a complete genome map of Streptococcus oralis strain SOT, Streptococcus oralis strain SOD and Streptococcus infantis strain SO and performed comparative genomic analysis among these three strains. The results showed that there are five genomic islands (GIs) in strain SOT and one CRISPR in strain SOD. Each genome harbors various pathogenic genes related to diseases and drug resistance, while the antibiotic resistance genes in strains SOT and SOD were quite similar but different from those in strain SO. In addition, we identified 17 main virulence factors and capsule-related genes in three strains. These results suggest the pathogenic potential of Streptococcus strains, which lay a foundation for the prevention and treatment of a Streptococcus oralis infection.
Topics: Anti-Bacterial Agents; Comparative Genomic Hybridization; Drug Resistance, Bacterial; Genes, Bacterial; RNA, Ribosomal, 16S; Streptococcus oralis; Virulence Factors
PubMed: 32334114
DOI: 10.1016/j.ygeno.2020.04.014