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Journal of Investigative Medicine High... 2024Brain abscess is a life-threatening infection that can occur secondary to contiguous or hematogenous spread. Several underlying conditions can lead to brain abscesses,...
Brain abscess is a life-threatening infection that can occur secondary to contiguous or hematogenous spread. Several underlying conditions can lead to brain abscesses, such as dental infection, otitis media, sinusitis, and immunosuppression. Esophageal perforation leading to brain abscesses is extremely rare. We report a rare case of a 32-year-old man who presented to the emergency department with progressive headaches and upper-extremity weakness. Upon further evaluation, computed tomography (CT) revealed multiple brain abscesses secondary to infection. The patient eventually underwent esophagogastroduodenoscopy (EGD), which showed a perforation in the middle third of the esophagus. This case highlights the importance of considering esophageal perforation as a predisposing condition for brain abscesses.
Topics: Male; Humans; Adult; Streptococcus intermedius; Esophageal Perforation; Brain Abscess; Streptococcal Infections; Tomography, X-Ray Computed
PubMed: 38504423
DOI: 10.1177/23247096241239572 -
Frontiers in Cellular and Infection... 2024Streptococci are primary colonizers of the oral cavity where they are ubiquitously present and an integral part of the commensal oral biofilm microflora. The role oral... (Review)
Review
Streptococci are primary colonizers of the oral cavity where they are ubiquitously present and an integral part of the commensal oral biofilm microflora. The role oral streptococci play in the interaction with the host is ambivalent. On the one hand, they function as gatekeepers of homeostasis and are a prerequisite for the maintenance of oral health - they shape the oral microbiota, modulate the immune system to enable bacterial survival, and antagonize pathogenic species. On the other hand, also recognized pathogens, such as oral and , which trigger the onset of dental caries belong to the genus . In the context of periodontitis, oral streptococci as excellent initial biofilm formers have an accessory function, enabling late biofilm colonizers to inhabit gingival pockets and cause disease. The pathogenic potential of oral streptococci fully unfolds when their dissemination into the bloodstream occurs; streptococcal infection can cause extra-oral diseases, such as infective endocarditis and hemorrhagic stroke. In this review, the taxonomic diversity of oral streptococci, their role and prevalence in the oral cavity and their contribution to oral health and disease will be discussed, focusing on the virulence factors these species employ for interactions at the host interface.
Topics: Humans; Dental Caries; Streptococcus; Streptococcus mutans; Streptococcus sobrinus; Mouth; Biofilms
PubMed: 38456080
DOI: 10.3389/fcimb.2024.1357631 -
Le Infezioni in Medicina 2024Viridans Group Streptococci (VGS) are a group of distinct species that can cause bacteraemia and other invasive infections. They are also among the common organisms...
BACKGROUND
Viridans Group Streptococci (VGS) are a group of distinct species that can cause bacteraemia and other invasive infections. They are also among the common organisms causing infective endocarditis. Data on the epidemiology and clinical profile of VGS is limited, especially from India.
METHODS
We conducted an electronic medical record-based retrospective analysis of patients with VGS bacteraemia admitted to our hospital between January 2012 to December 2021. Blood cultures were incubated by BacT/ALERT system and bacterial identification and susceptibility testing were done by using the VITEK 2 microbial identification system. Susceptibility test reporting was as per Clinical and Laboratory Standards Institute (CLSI) guidelines. The incidence, clinical profile, source of bacteraemia, co-morbidities and antimicrobial resistance among VGS bacteraemia were analyzed.
RESULTS
VGS were isolated in 219 patients, accounting for 3.2% of positive blood cultures during the period studied. The median age of the patients was 58 years and 69% were males. Diabetes mellitus was the most common co-morbidity (55%) followed by chronic kidney disease and chronic liver disease. Patients with haematological malignancy and neutropenia were few. Intra-abdominal infections were the most common source of infection and was noted in 26%. Infective endocarditis was diagnosed in only 10% of the cases. was the most common species isolated followed by and . 9.58% of the isolates could not be identified up to the species level. Overall penicillin susceptibility was 71% and ceftriaxone susceptibility was 92%, with individual species variation. In-hospital mortality was 19%.
CONCLUSIONS
VGS are an important cause of bacteraemia and was associated with 19% mortality in our study. High rates of penicillin and ceftriaxone resistance are a reason of concern. Molecular diagnostics like matrix assisted laser desorption ionization-time of flight (MALDI-TOF) identification must be increasingly applied for species identification considering that a substantial number of isolates were not identified to species level.
PubMed: 38456022
DOI: 10.53854/liim-3201-5 -
BMC Oral Health Mar 2024This study was conducted to investigate the efficiency of periodontal ligament (PDL) stem cell-derived exosome-loaded Emodin (Emo@PDL-Exo) in antimicrobial photodynamic...
BACKGROUND
This study was conducted to investigate the efficiency of periodontal ligament (PDL) stem cell-derived exosome-loaded Emodin (Emo@PDL-Exo) in antimicrobial photodynamic therapy (aPDT) on Streptococcus mutans and Lactobacillus acidophilus as the cariogenic bacteria.
MATERIALS AND METHODS
After isolating and characterizing PDL-Exo, the study proceeded to prepare and verify the presence of Emo@PDL-Exo. The antimicrobial effect, anti-biofilm activity, and anti-metabolic potency of Emo, PDL-Exo, and Emo@PDL-Exo were then evaluated with and without irradiation of blue laser at a wavelength of 405 ± 10 nm with an output intensity of 150 mW/cm for a duration of 60 s. In addition, the study assessed the binding affinity of Emodin with GtfB and SlpA proteins using in silico molecular docking. Eventually, the study examined the generation of endogenous reactive oxygen species (ROS) and changes in the gene expression levels of gelE and sprE.
RESULTS
The study found that using Emo@PDL-Exo-mediated aPDT resulted in a significant decrease in L. acidophilus and S. mutans by 4.90 ± 0.36 and 5.07 log CFU/mL, respectively (P < 0.05). The study found that using Emo@PDL-Exo for aPDT significantly reduced L. acidophilus and S. mutans biofilms by 44.7% and 50.4%, respectively, compared to untreated biofilms in the control group (P < 0.05). Additionally, the metabolic activity of L. acidophilus and S. mutans decreased by 58.3% and 71.2%, respectively (P < 0.05). The molecular docking analysis showed strong binding affinities of Emodin with SlpA and GtfB proteins, with docking scores of -7.4 and -8.2 kcal/mol, respectively. The study also found that the aPDT using Emo@PDL-Exo group resulted in the most significant reduction in gene expression of slpA and gtfB, with a decrease of 4.2- and 5.6-folds, respectively, compared to the control group (P < 0.05), likely due to the increased generation of endogenous ROS.
DISCUSSION
The study showed that aPDT using Emo@PDL-Exo can effectively reduce the cell viability, biofilm activity, and metabolic potency of S. mutans and L. acidophilus. aPDT also significantly reduced the expression levels of gtfB and slpA mRNA due to the increased endogenous ROS generation. The findings suggest that Emo@PDL-Exo-mediated aPDT could be a promising antimicrobial approach against cariogenic microorganisms.
Topics: Humans; Photosensitizing Agents; Emodin; Reactive Oxygen Species; Exosomes; Molecular Docking Simulation; Periodontal Ligament; Photochemotherapy; Anti-Infective Agents; Streptococcus mutans; Biofilms; Stem Cells
PubMed: 38454402
DOI: 10.1186/s12903-024-04062-7 -
Archives of Oral Biology May 2024This systematic review summarizes the current knowledge on the association between the oral microbiota and dental caries in adolescents. (Review)
Review
OBJECTIVE
This systematic review summarizes the current knowledge on the association between the oral microbiota and dental caries in adolescents.
DESIGN
An electronic search was carried out across five databases. Studies were included if they conducted research on generally healthy adolescents, applied molecular-based microbiological analyses and assessed caries status. Data extraction was performed by two reviewers and the Newcastle-Ottawa Scale was applied for quality assessment.
RESULTS
In total, 3935 records were reviewed which resulted in a selection of 20 cross-sectional studies (published 2005-2022) with a sample size ranging from 11 to 614 participants including adolescents between 11 and 19 years. The studies analyzed saliva, dental biofilm or tongue swabs with Checkerboard DNA-DNA hybridization, (q)PCR or Next-Generation Sequencing methods. Prevotella denticola, Scardoviae Wiggsiae, Streptococcus sobrinus and Streptococcus mutans were the most frequently reported species presenting higher abundance in adolescents with caries. The majority of the studies reported that the microbial diversity was similar between participants with and without dental caries.
CONCLUSION
This systematic review is the first that shows how the oral microbiota composition in adolescents appears to differ between those with and without dental caries, suggesting certain taxa may be associated with increased caries risk. However, there is a need to replicate and expand these findings in larger, longitudinal studies that also focus on caries severity and take adolescent-specific factors into account.
Topics: Humans; Adolescent; Dental Caries; Cross-Sectional Studies; Streptococcus mutans; Saliva; Microbiota; DNA
PubMed: 38447351
DOI: 10.1016/j.archoralbio.2024.105933 -
Molecules (Basel, Switzerland) Feb 2024Dental caries (DC) is the most common oral pathology. The main bacteria responsible for DC is . One of the strategies that can decrease or eliminate the risk of DC...
Dental caries (DC) is the most common oral pathology. The main bacteria responsible for DC is . One of the strategies that can decrease or eliminate the risk of DC development is using compounds that will inhibit both the growth and virulence factors of . Tannins are plant polyphenols that have strong antibacterial activity. The purpose of this study was to assess the antibacterial activity of three tannins against In this investigation, microbiological tests (MIC and MBC) and physicochemical techniques like the fluorescence measurements of tannins' interaction with cell membrane and membrane proteins, zeta potential, and thermodynamic analyses were used to obtain knowledge about the antibacterial potential of the investigated compounds against as well as about the mechanisms associated with antibacterial activity. The obtained results demonstrate that the used compounds exhibit high antibacterial activity against . The mechanisms of their antibacterial activity are linked to the strong change in the membrane fluidity and potential, and to their interaction with membrane proteins that can result in great disturbance of bacterial physiology and ultimately the inhibition of bacterial growth, triggering their death. Therefore, it can be concluded that the investigated compounds can be potentially used as natural factors in the prevention of dental caries.
Topics: Humans; Streptococcus mutans; Tannins; Dental Caries; Anti-Bacterial Agents; Polyphenols; Membrane Proteins; Biofilms; Microbial Sensitivity Tests
PubMed: 38398630
DOI: 10.3390/molecules29040879 -
Photodiagnosis and Photodynamic Therapy Apr 2024Streptococcus mutans and Candida albicans are associated with caries recurrence. Therefore, this study evaluated the combination of a Ru(II)-loaded resin-based dental...
BACKGROUND
Streptococcus mutans and Candida albicans are associated with caries recurrence. Therefore, this study evaluated the combination of a Ru(II)-loaded resin-based dental material (RDM) and antimicrobial photodynamic therapy (aPDT) against a dual-species biofilm of S. mutans and C. albicans.
METHODS
An aPDT protocol was established evaluating Ru(II)'s photocatalytic activity and antimicrobial potential under blue LED irradiation (440-460 nm, 22.55 mW/cm) at different energy densities (0.00, 6.25, 20.25, 40.50 J/cm2). This evaluation involved singlet oxygen quantification and determination of minimum inhibitory concentration (MIC) and minimum bactericidal/fungicidal concentration (MBC/MFC). The biofilm was grown (72 h) on resin disks prepared with Ru(II)-doped RDM (0.00, 0.56, or 1.12 %) and samples were exposed to aPDT or dark conditions. The biofilm was then harvested to analyze cell viability (CFU counts) and formation of soluble and insoluble exopolysaccharides.
RESULTS
The photocatalytic activity of Ru(II) was concentration and energy density dependent (p < 0.05), and MIC/MBC values were reduced for the microorganisms after LED irradiation (40.5 J/cm); therefor, this energy density was chosen for aPDT. Although incorporation of Ru(II) into RDM reduced the biofilm growth compared to Ru(II)-free RDM for both species in dark conditions (p < 0.05), aPDT combined with an Ru(II)-loaded RDM (0.56 or 1.12 %) potentialized CFU reductions (p < 0.05). Conversely, only 1.12 % Ru(II) with LED irradiation showed lower levels of both soluble and insoluble exopolysaccharides compared to Ru(II)-free samples in dark conditions (p < 0.05).
CONCLUSIONS
When the Ru(II)-loaded RDM was associated with blue LED, aPDT reduced cell viability and lower soluble and insoluble exopolysaccharides were found in the cariogenic dual-species biofilm.
Topics: Photochemotherapy; Biofilms; Streptococcus mutans; Photosensitizing Agents; Candida albicans; Ruthenium; Microbial Sensitivity Tests; Dental Materials; Singlet Oxygen; Dental Caries; Composite Resins
PubMed: 38395246
DOI: 10.1016/j.pdpdt.2024.104019 -
Clinical Oral Investigations Feb 2024To compare the antibacterial effect of Nanosilver Fluoride varnish (NSF) varnish, P11-4 and Sodium Fluoride (NaF) varnish against salivary Streptococcus mutans (S.... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVES
To compare the antibacterial effect of Nanosilver Fluoride varnish (NSF) varnish, P11-4 and Sodium Fluoride (NaF) varnish against salivary Streptococcus mutans (S. mutans) and Lactobacilli.
METHODS
66 patients aged 10-24 years old were randomly assigned to receive single application of NSF, P11-4 or NaF varnish. Baseline unstimulated saliva samples were collected before the agents were applied and S.mutans and Lactobacilli colony forming units (CFU) were counted. After one, three and six months, microbiological samples were re-assessed. Groups were compared at each time point and changes across time were assessed. Multivariable linear regression compared the effect of P11-4 and NSF to NaF on salivary S. mutans and Lactobacilli log count at various follow up periods.
RESULTS
There was a significant difference in salivary S. mutans log count after 1 month between P11-4 (B= -1.29, p = 0.049) and NaF but not at other time points nor between NSF and NaF at any time point. The significant reduction in bacterial counts lasted up to one month in all groups, to three months after using P11-4 and NaF and returned to baseline values after six months.
CONCLUSION
In general, the antimicrobial effect of P11-4 and NSF on salivary S. mutans and Lactobacilli was not significantly different from NaF varnish. P11-4 induced greater reduction more quickly than the two other agents and NSF antibacterial effect was lost after one month.
CLINICAL RELEVANCE
NSF varnish and P11-4 have antimicrobial activity that does not significantly differ from NaF by 3 months. P11-4 has the greatest antibacterial effect after one month with sustained effect till 3 months. The antibacterial effect of NSF lasts for one month. NaF remains effective till 3 months.
TRIAL REGISTRATION
This trial was prospectively registered on the clinicaltrials.gov registry with ID: NCT04929509 on 18/6/2021.
Topics: Adolescent; Child; Humans; Young Adult; Anti-Bacterial Agents; Anti-Infective Agents; Dental Caries; Fluorides; Fluorides, Topical; Silver Compounds; Sodium; Sodium Fluoride; Streptococcus mutans; Nanostructures
PubMed: 38388987
DOI: 10.1007/s00784-024-05562-0 -
Microbiology Spectrum Apr 2024The oral microbiome plays an important role in protecting oral health. Here, we established a controlled mixed-species biofilm model and used it to assess the impact of...
The oral microbiome plays an important role in protecting oral health. Here, we established a controlled mixed-species biofilm model and used it to assess the impact of glucose and lactate on the ability of , an acidogenic and aciduric species, to compete with commensal oral bacteria. A chemically defined medium was developed that supported the growth of and four common early colonizers of dental plaque: , , , and . Biofilms containing the early colonizers were developed in a continuous flow bioreactor, exposed to , and incubated for up to 7 days. The abundance of bacteria was estimated by quantitative polymerase chain reaction (qPCR). At high glucose and high lactate, the pH in bulk fluid rapidly decreased to approximately 5.2, and outgrew other species in biofilms. In low glucose and high lactate, the pH remained above 5.5, and was the most abundant species in biofilms. By contrast, in low glucose and low lactate, the pH remained above 6.0 throughout the experiment, and the microbial community in biofilms was relatively balanced. Fluorescence hybridization confirmed that all species were present in the biofilm and the majority of cells were viable using live/dead staining. These data demonstrate that carbon source concentration is critical for microbial homeostasis in model oral biofilms. Furthermore, we established an experimental system that can support the development of computational models to predict transitions to microbial dysbiosis based on metabolic interactions.IMPORTANCEWe developed a controlled (by removing host factor) dynamic system metabolically representative of early colonization of not measurable . Hypotheses on factors influencing colonization, such as community composition and inoculation sequence and the effect of metabolite concentrations, can be tested and used to predict the effect of interventions such as dietary modifications or the use of toothpaste or mouthwash on colonization. The defined model (species and medium) can be simulated in an model to explore more of the parameter space.
Topics: Streptococcus mutans; Lactic Acid; In Situ Hybridization, Fluorescence; Glucose; Biofilms
PubMed: 38376204
DOI: 10.1128/spectrum.03713-23 -
EBioMedicine Mar 2024Lifestyle- and sucrose-dependent polymicrobial ecological shifts are a primary cause of caries in populations with high caries prevalence. In populations with low...
BACKGROUND
Lifestyle- and sucrose-dependent polymicrobial ecological shifts are a primary cause of caries in populations with high caries prevalence. In populations with low prevalence, PRH1, PRH2 susceptibility and resistance phenotypes may interact with the Streptococcus mutans adhesin cariogenicity phenotype to affect caries progression, but studies are lacking on how these factors affect the microbial profile of caries.
METHODS
We analysed how the residency and infection profiles of S. mutans adhesin (SpaP A/B/C and Cnm/Cbm) phenotypes and commensal streptococci and lactobacilli influenced caries progression in a prospective case-referent sample of 452 Swedish adolescents with high (P4a), moderate (P6), and low (P1) caries PRH1, PRH2 phenotypes. Isolates of S. mutans from participants were analysed for adhesin expression and glycosylation and in vitro and in situ mechanisms related to caries activity.
FINDINGS
Among adolescents with the resistant (P1) phenotype, infection with S. mutans high-virulence phenotypes was required for caries progression. In contrast, with highly (P4a) or moderately (P6) susceptible phenotypes, caries developed from a broader polymicrobial flora that included moderately cariogenic oral commensal streptococci and lactobacilli and S. mutans phenotypes. High virulence involved unstable residency and fluctuating SpaP ABC, B-1, or Cnm expression/glycosylation phenotypes, whereas low/moderate virulence involved SpaP A phenotypes with stable residency. Adhesin phenotypes did not display changes in individual host residency but were paired within individuals and geographic regions.
INTERPRETATION
These results suggest that receptor PRH1, PRH2 susceptibility and resistance and S. mutans adhesin virulence phenotypes specify different microbial profiles in caries.
FUNDING
Swedish Research Council and funding bodies listed in the acknowledgement section.
Topics: Adolescent; Humans; Streptococcus mutans; Virulence; Dental Caries Susceptibility; Biofilms; Adhesins, Bacterial; Phenotype
PubMed: 38364699
DOI: 10.1016/j.ebiom.2024.105001