Dental Bacteria Research Articles

Anti-Caries Effect of a Mouthwash Containing Sambucus williamsii var. coreana Extract: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial.

This study was performed to verify the clinical effect of a mouthwash containing Sambucus williamsii var. coreana extract on the acid production of oral bacteria and bacteria involved in dental caries. A randomized, double-blind, and placebo-controlled trial was conducted on 66 patients of the following groups: a Sambucus williamsii var. coreana extract gargle group (n = 34) and a saline solution gargle group (n = 32). According to the application time of a mouthwash (before gargle application, immediately after gargle application, and five days after gargle application), we examined the emergence of dental caries-causing bacteria by PCR analysis and changes in the amount of acid production in dental plaque through a Cariview test. As a result of verifying the effect of inhibiting and preventing dental caries in the oral environment, the dental caries-causing bacteria decreased in the Sambucus williamsii var. coreana extract gargle group compared to the saline gargle group. In particular, Streptococcus mutans showed a marked decrease from immediately after application of gargle to 5 days after application. In addition, the mouthwash containing Sambucus williamsii var. coreana extract did not cause acid production and had low dental caries activity. A mouthwash containing Sambucus williamsii var. coreana extract, a natural substance, can be used as an anti-dental caries agent and be commercialized as an effective dental caries prevention agent that is safe for teeth and has an excellent antibacterial effect.

Effect of spiramycin and metronidazole on canine dental biofilm bacteria

Periodontal diseases are the most common condition in companion animal practice. The administration of antibiotics is associated with the therapy of these diseases. The aim of the present study was to verify the effect of antibiotics on canine dental biofilm bacteria due to increasing antibiotic resistance. Dental biofilm samples were taken from six dogs before and after administration of antibiotics, specifically, the combination of spiramycin and metronidazole. The samples were cultured on solid media under aerobic and anaerobic conditions. Sequencing analysis of the 16S rRNA gene was used to identify bacterial isolates. In addition, total bacterial DNA was extracted from samples from one dog and the V3−V4 region of the 16S rRNA gene was sequenced using the Illumina MiSeq platform. Using cultivation, 55 isolates belonging to 4 phyla were isolated before antibiotics administration, and 36 isolates belonging to 3 phyla were isolated after antibiotics administration. A significant decrease was noted in the genera Porphyromonas, Neisseria and Frederiksenia, whereas there was a significant increase in the genus Streptococcus. Of the total microbiota, there were 69 operational taxonomic units (OTUs) belonging to 11 phyla before antibiotics administration, and 51 OTUs belonging to 8 phyla after antibiotics administration. A significant decrease was recorded in the genus Porphyromonas, while a significant increase in the genus Capnocytophaga. The significant effect of spiramycin and metronidazole on the genus Porphyromonas at the time of their administration was confirmed by both cultivation and amplicon sequencing.

A Randomized, Double-Blind, Placebo-Controlled Clinical Trial of a Mouthwash Containing Glycyrrhiza uralensis Extract for Preventing Dental Caries.

This study sought to confirm the effect of using a mouthwash containing Glycyrrhiza uralensis extract for oral health management by investigating changes in the pH of dental plaque and bacteria that cause dental caries. A randomized, double-blind, placebo-controlled study was conducted on 60 subjects categorized in either the Glycyrrhiza uralensis extract gargle group (n = 30) or the saline gargle group (n = 30). Scaling was conducted in order to ensure the homogeneity of the oral environment, while gargling was performed once daily before the subjects went to bed for 5 days based on the group. Caries activity was assessed using the Cariview test, while detection of the bacteria that cause dental caries was confirmed using microbiological analysis. All clinical measurements and evaluations were conducted by two trained dental hygienists under the supervision of a dentist. Based on the analysis of dental caries activity and dental caries-causing bacteria, the Glycyrrhiza uralensis extract gargle group showed a clear decrease in bacteria compared to the saline gargle group. Glycyrrhiza uralensis extract demonstrated no risk of tooth demineralization. It also showed excellent antibacterial activity through inhibition and effective reduction of bacteria that cause dental caries. Therefore, the mouthwash containing Glycyrrhiza uralensis extract is an effective oral care product suitable for use as an effective dental caries prevention agent.

Investigating the mechanophysical and biological characteristics of therapeutic dental cement incorporating copper doped bioglass nanoparticles

ObjectiveThis study was investigated the mechanophysical properties of zinc phosphate cement (ZPC) with or without the copper doped bioglass nanoparticles (Cu-BGn) and their biological effect on dental pulp human cells and bacteria. Materials and methodsCu-BGn were synthesized and characterized firstly and then, the experimental (Cu-ZPC) and control (ZPC) samples were fabricated with similar sizes and/or dimensions (diameter: 4 mm and height: 6 mm) based on the International Organization of Standards (ISO). Specifically, various concentrations of Cu-BGn were tested, and Cu-BGn concentration was optimized at 2.5 wt% based on the film thickness and overall setting time. Next, we evaluated the mechanophysical properties such as compressive strength, elastic modulus, hardness, and surface roughness. Furthermore, the biological behaviors including cell viability and odontoblastic differentiation by using dental pulp human cells as well as antibacterial properties were investigated on the Cu-ZPC. All data were analyzed statistically using SPSS® Statistics 20 (IBM®, USA). p < 0.05 (*) was considered significant, and ‘NS’ represents nonsignificant. ResultsCu-BGn was obtained via a sol-gel method and added onto the ZPC for fabricating a Cu-ZPC composite and for comparison, the Cu-free-ZPC was used as a control. The film thickness (≤ 25 µm) and overall setting time (2.5–8 min) were investigated and the mechanophysical properties showed no significance (‘NS’) between Cu-ZPC and bare ZPC. However, cell viability and odontoblastic differentiation, alkaline phosphate (ALP) activity and alizarin red S (ARS) staining were highly stimulated in the extracts from the Cu-ZPC group compared to the ZPC group. Additionally, the antibacterial test showed that the Cu-ZPC extracts were more effective than the ZPC extracts (p < 0.05). SignificanceCu-ZPC showed adequate mechanophysical properties (compressive strength, hardness, and surface roughness) and enhanced odontoblastic differentiation as well as antibacterial properties compared to the ZPC-only group. Based on the findings, the fabricated Cu-ZPC might have the potential for use in the field of dental medicine and clinical applications.

Efficacy of Silver Diamine Fluoride on Streptococcus mutans Count Present in Saliva.

ABSTRACTAim and objectiveEvaluate the efficacy and longevity of silver diamine fluoride (SDF) to inhibit the dental caries initiator bacteria; Streptococcus mutans count in saliva.Study designTwenty children having class I and II dental caries with no prior restorations were included in the study. Unstipulated saliva samples were collected before and immediately after application of SDF, 1, 3, and 6 months after application, and intergroup comparison was done.Materials and methodsSilver diamine fluoride was applied on the cavitated surfaces with microbrush tip under isolation, then wait for 4 minutes and washed away all surfaces with water spray. Saliva was collected in a sterile saliva collection tube and sent for microbiological culture assessment. CFU/mL of S. mutans count was done with the Digital colony counter. For statistical analysis, paired T-test was performed.ResultsSilver diamine fluoride showed a significant drop in CFU/mL of S. mutans count at 1 month then 3 and 6 months accordingly.ConclusionSilver diamine fluoride can be used to prevent and arrest dental caries and the best result can be achieved by quarterly application.How to cite this articleChakraborty S, Gupta N, Gambhir N, et al. Efficacy of Silver Diamine Fluoride on Streptococcus mutans Count Present in Saliva. Int J Clin Pediatr Dent 2021;14(5):700–704.

The Comparison of Antimicrobial Effect of Nigella sativa Nanoparticle and Chlorhexidine Emulsion on the Most Common Dental Cariogenicic Bacteria.

Background: Tooth decay and periodontal disease are the most common chronic human and oral diseases, respectively, and bacterial plaque has a major role in their occurrence. Because of the importance of plaque control, this study was done to compare the antimicrobial effects of Nigella sativa nanoparticles and chlorhexidine emulsion on the most common dental cariogenicic bacteria. Methods: In this experimental study, the effects of 0.2% chlorhexidine mouthwash and Nigella sativa nanoparticle with different dilutions on Streptococcus mutans, Streptococcus sobrinus, Streptococcus salivarius, Lactobacillus acidophilus, Minococcal fecalis, and Enterococcus fecalis were compared using minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assessment. Data were analyzed by SPSS Version 16.0 software, and statistical tests, including an independent sample t test. Results: Mean diameters of growth inhibition zone because of the nanoemulsion of Nigella sativa nanoparticle was close to each other in different bacteria (p=0.665). In addition, there was no significant difference between these values because of different dilutions of nanoemulsion even in different microbial species (p=0.778). The MIC and lethal concentrations of Nigella sativa nanoemulsion were similar for Enterococcus faecalis and Streptococcus mutans, and it was higher than other bacteria. In comparison, the MIC and MBC values of all bacteria in chlorhexidine were lower than those of the nanoemulsion. Conclusion: MIC and MBC values showed that Nigella sativa nanoemulsion affects tooth cariogenicic bacteria. Enterococcus faecalis and Lactobacillus acidophilus were the most resistant and susceptible bacteria to this nanoparticle, respectively, while the antimicrobial effects of Nigella sativa nanoemulsion were weaker than the chlorhexidine mouthwash.

Antibacterial properties in-vitro of Mexican serviceberry extracts against dental biofilm species

BACKGROUND: The Mexican serviceberry, Malacomeles denticulata, have been used as a successful oral therapy by Mexican communities without enough scientific support. OBJECTIVE: To evaluate the M. denticulata extracts with selective antibacterial properties over dental biofilm bacteria. METHODS: Fruit, Leaf, and Stem of M. denticulata extracts were evaluated with micro-broth dilution method using ATCC bacteria. OD600 values had compared against each positive control (T-student-test). Anaerobically viability had confirmed by Colony-Forming-Units. Thin-Layer-Chromatography was used to identify the number of compounds and phytochemicals to identify secondary metabolites of the selected extracts. RESULTS: Streptococcus mutans showed Minimum-Bactericidal-Concentrations_(MBC) at 30 mg/mL to Fruit, Leaf, and Stem extracts. Periodontal-pathogens Aggregatibacter actinomycetemcomitans serotype b_(MBC = 30 mg/mL_NS); Fusobacterium nucleatum subsp. nucleatum_(MBC = 30 mg/mL_p&lt;0.05); Parvimonas micra_(MBC = 15 mg/mL_NS); Porphyromonas gingivalis_(MBC = 30 mg/mL_NS); and Prevotella intermedia_(MBC = 3.75 mg/mL_NS) presented higher sensitivity to Leaf-Methanol, than the primary colonizers. Phytochemicals showed positive results to anthraquinones, coumarins, flavonoids, saponins, saponins steroids/triterpenoids, steroids/triterpenes, and tannins/phenols. CONCLUSION: We suggest the natural extracts of fruit and leaf of the Mexican serviceberry for the preventive use over the oral cariogenic or periodontal biofilm species, by their selective antibacterial properties against pathogenic species evaluated in-vitro, and due to the presence of antibacterial secondary metabolites identified as flavonoids and saponins of M. denticulata leaf extracts.

A Novel Dental Caries Model Replacing, Refining, and Reducing Animal Sacrifice

In vitro and in vivo models simulating the dental caries process enable the evaluation of anti-caries modalities for prevention and treatment. Animal experimentation remains important for improving human and animal health. Nonetheless, reducing animal sacrifice for research is desirable. The aim of the study was to establish a new reproducible in vitro caries model system and compare it to an in vivo model using similar conditions. Hemi-mandibles were extracted from previously euthanized healthy 10-week-old BALB/C female mice. Jaws were subjected to saliva, high-sucrose diet, and dental caries bacteria Streptococcus mutans UA159 for 5 days. Similar caries induction protocol was used in vivo in fifteen BALB/c female mice (6–7 weeks old) and compared to the in vitro model. Caries lesions were assessed clinically by photographic analysis and µCT analysis, and bacterial growth was evaluated. Under in vitro experimental conditions, carious lesions evolved within 5 days, prominently in the depth of the occlusal fissures in the control group as depicted by photographic analysis, µCT analysis, and bacterial growth. The developed in vitro caries model presented in this study may be a novel animal sparing model for caries disease studies and can be used widely to evaluate the efficacy of different antibacterial dental materials.

Antibiogram types of bacterial isolates from dental caries patients attending clinic at a teaching hospital in Nigeria

Around the world dental caries is amongst the commonest disease affecting all age groups and yet seen by all as less common and severe; especially among Africans. Worrisome, our recent study showed isolated dental caries bacteria to be resistant to available antibiotics. In this study, antibiogram typing of bacteria isolated from dental caries of patients attending the dental clinic at Irrua Specialist Teaching Hospital, Nigeria were investigated. The study involves 223 bacteria positive samples (Streptococcus mutans = 150; Streptococcus sobrinus = 36; Lactobacillus acidophilus = 22; Streptococcus salivarius = 10; Streptococcus mitis = 4) collected and screened against 24 antibiotics divided into 8 groups of 3 each. Antibiogram study was conducted using Ajumali’s mnemonic coding and the results were presented in tables. The Ajumali’s mnemonic coding showed that no two strains of Streptococcus salivarius and Streptococcus mitis were repeated. However, 18.8%, 43.71%, and 61.11% of Lactobacillus acidophilus, Streptococcus mutans, and Streptococcus sobrinus strain respectively presented repeated Ajumali’s mnemonic codes. The “00000005, 02000005, 03010005, 01010005 and 63112005” mnemonic codes appear in both S. mutans and S. sobrinus isolates, “02000004’’ appears in both L. acidophilus and S. mutans, 03000005 appears in both S. salivarius and S. mutans and 03110005 in S. mitis and S. sobrinus. The repetition of mnemonic codes from L. acidophilus, S. mutans, and S. sobrinus isolates and the appearance of codes between isolates indicate that some isolates may have strains with phenotypical similarities.

Gut Extracts of Rhynchophorus ferrugineus Larvae Olivier Affecting Bacterial Dental Caries

In vitro study was conducted to explore antibacterial properties of the larval gut extracts of Rhynchophorus ferrugineus (Red Palm Weevil) Oliver. Larval gut extracts were tested against salivary bacteria causing dental carries using the agar well diffusion method. The gut extracts significantly affected the growth of both Klebsiella spp. and Streptococcus viridans. The two bacterial species revealed significant differences in their sensitivity to the extract. The extract efficacy depended upon the concentration and time of exposure. When using 100%concentration of the extract, the mean of inhibition zones for S. viridans and Klebsiella spp. at 24 h after treatment were 1.61 mm and 2.50 mm, respectively. At 48 h post-treatment, the mean of inhibition zones for S. viridans and Klebsiella spp. were 1.96 mm and 2.66 mm. After 72 hours, the means zones were 2.28 mm and 2.91 mm, respectively. Electron microscopic examinations showed morphological changes of the outer membrane of bacteria with a noticeable damage as a result of exposure to the gut extract. The results suggest potential use of these extracts against dental caries bacteria.

Isolation and Characterization of Two Virulent Phages to Combat Staphylococcus aureus and Enterococcus faecalis causing Dental Caries

This study aimed to isolate and characterize bacteriophages, as a biocontrol agent, against certain antibiotic-resistant bacteria causing dental caries. Here, two dental caries-causing bacteria S. aureus and E. faecalis were isolated and characterized biochemically using the automated VITEK® 2 system. Antibiotic sensitivity pattern of the isolated dental caries bacteria was assessed against selection of antibiotics. The two isolates showed resistance against most of the tested antibiotics. To overcome this problem, two lytic phages vB_SauM-EG-AE3 and vB_EfaP-EF01 were isolated, identified, and applied to control the growth of S. aureus and E. faecalis, respectively. Phages were identified morphologically using TEM and showed that vB_SauM-EG-AE3 phage is related to Myoviridae and vB_EfaP-EF01 phage belongs to Podoviridae. The two phages exhibited high lytic activity, high stability, and a narrow host range. The one-step growth curve of phages showed burst sizes of 78.87 and 113.55 PFU/cell with latent periods of 25 and 30 minutes for S. aureus phage and E. faecalis phage respectively. In addition, the two phages showed different structural protein profiles and exhibited different patterns using different restriction enzymes. The genome sizes were estimated to be 13.30 Kb and 15.60 Kb for phages vB_SauM-EGAE3, vB_EfaP-EGAE1, respectively. Complete inhibition of bacterial growth was achieved using phages with MOIs of 103, 102 and 10 after 1, 3, 5, and 24 h of incubation at 37°C. Hence, this study indicates that the isolated bacteriophages are promising biocontrol agents that could challenge antibiotic-resistant dental caries bacteria to announce new successful alternatives to antibiotics.

Catechin as the Most Efficient Bioactive Compound from Azadirachta indica with Antibiofilm and Anti-quorum Sensing Activities Against Dental Biofilm: an In Vitro and In Silico Study.

Neem (Azadirachta indica [AI]) is a unique and traditional source of antioxidant and antibacterial compounds. The GC-MS studies revealed that phytoextract of Azadirachta indica comprises a large number of phytocompounds that possess the efficacy of inhibiting the biofilm. It was observed that phytocompounds like catechin showed maximum eradication of biofilm along with the degradation of EPS structural components like carbohydrates and proteins compared to quercetin, nimbolide, nimbin, and azardirachtin, and hence, catechin was proved to be the best against dental plaque-forming bacteria. It was also observed that catechin was able to bring about a marked reduction in quorum sensing (QS) both in Alcaligenes faecalis and Pseudomonas gingivalis dental biofilm-forming strains. The extent of such reduction was maximum for catechin (94.56±2.56% in P. gingivalis & 96.56±2.5 in A. faecalis) in comparison to other bioactive compounds. It was further observed that the bioactive compounds possess the ability to quickly pass across the membrane and bring about inhibition in the DNA and RNA content of the sessile cells. This was further validated by microscopic and in silico studies. Thus, this study revealed that catechin obtained from the phytoextract of AI showed a marked ability to inhibit the dental biofilm and can be used as a natural drug-like compound in treating biofilm-associated chronic infections.

Lactobacillus reuteri AN417 cell-free culture supernatant as a novel antibacterial agent targeting oral pathogenic bacteria

Lactobacillus reuteri AN417 is a newly characterized probiotic strain. The activity of AN417 against oral pathogenic bacteria is unknown. We investigated the antibacterial activity of cell-free L. reuteri AN417 culture supernatant (LRS) against three oral pathogens: Porphyromonas gingivalis, Fusobacterium nucleatum, and Streptococcus mutans. P. gingivalis and F. nucleatum have been implicated in periodontal disease, whereas S. mutans causes dental caries. Exposing these oral pathogenic bacteria to LRS significantly reduced their growth rates, intracellular ATP levels, cell viability, and time-to-kill. The minimal inhibitory volume of LRS was 10% (v/v) against P. gingivalis, 20% (v/v) for F. nucleatum, and 30% (v/v) for S. mutans. LRS significantly reduced the integrity of biofilms and significantly suppressed the expression of various genes involved in P. gingivalis biofilm formation. The L. reuteri AN417 genome lacked genes encoding reuterin, reuteran, and reutericyclin, which are major antibacterial compounds produced in L. reuteri strains. LRS treated with lipase and α-amylase displayed decreased antibacterial activity against oral pathogens. These data suggest that the antibacterial substances in LRS are carbohydrates and/or fatty acid metabolites. Our results demonstrate that LRS has antimicrobial activity against dental pathogenic bacteria, highlighting its potential utility for the prevention and treatment of P. gingivalis periodontal disease.

Systemic Immunological Responses Among Dental Infection Patients

Evaluating of some immunological responses among dental infection patients is essential in the clinical management of oral infection. Our study considered isolation of dental infection bacteria and quantitative evaluation of serum. IgA, IL-4, IL-7 and CD4 and CD8 molecules among dental plaque patients and control group. Oral bacteria from dental infection patients were isolated in appropriate media and diagnosed by biochemical tests and in vitro quantitative determination of serum IgA, IL-4, IL-7 and CD4 and CD8 molecules using ELISA technique. Single and mixed bacterial isolates were noted, mixed infection were (59.25%), the nature of bacteria was Gram positive cocci <i>Streptococcus viridans</i>, <i>Streptococcus pyogenes</i> and <i>Staphylococcus aureus</i>, and <i>Lactocacilli </i>spps, in addition to Gram negative rods black- pigmented bacteria, <i>Klebsilla pneumonia</i>, and <i>Esherishia coli</i>. Serum IgA was higher in patients (368.8±182.5) ng\ml than in control group (319.92±79.26) ng\ml. Serum IL-4 was higher patients (285.33±86.12) pg/ml than in control group (257.7±94.14) pg\ml. Serum IL-7 was higher in control group (19.59±4.14) pg/ml than in dental plaque patients (17.98±3.18) pg /ml. Serum CD4 molecules was higher in control group (1.371±0.5242) ng/ml than in dental plaque patients (1.326±0.1292) ng/ml. Serum CD8 molecules shows non-significant elevation in patients group 0.5825±0.02717 (ng\ml) than in control group 0.51±0.01643 (ng\ml) P≤0.05. Mean of the CD4/CD8 ratio was higher 2.783±1.126 in control group while it was 2.355±0.24 in dental plaque patients, however the differences were non-significant (P≤0.05). The present study conclude that the bacteria isolated from dental infection patients were mixed more than single infection, there were non-significant elevation in IgA, IL-4, and CD8 in patients while IL-7 and CD4 was lower in patients group than in control group, while CD4\CD8 ratio were lower in patients group, these result reflect the fact that mucosal antigen induce systemic tolerance to some extent since these bacteria present in oral cavity in early childhood. Therefor removing these bacteria always the best way to prevent such infections.

Interaction of human oral cancer and the expression of virulence genes of dental pathogenic bacteria

Oral squamous cell carcinoma (OSCC) are one of the major causes of cancer morbidity and mortality worldwide. Dental microbiome has been considered as inducing agents in oral carcinogenesis. Therefore, the objective of this study was to investigate the interaction of the gene expression of the dental microbiome and OSCC patients. A cross-sectional study was designed by recruiting confirmed OSCC patients attending the University hospital during October 2018 and July 2019. The dental bacteria were isolated and confirmed by PCR technique. The expression of host and bacterial virulence genes was determined using qPCR. This study shows that 54% of T. forsythia found to be the most predominant organisms in 30 positive cases, followed by 34% of Campylobacter rectus and 29% of Prevotella intermedia. The expression of mRNA levels of bspA, csxA, fadA and interpain A in the OSCC- bacteria positive cases was significantly higher than the control group (P < 0.001). It was further found that interpainA, csxA, fadA, and bspA genes have the potential effects on the cellular gene expression in OSCC patients. A significant correlation was seen between expression patterns of CXCL10, DIAPH1, NCLN and MMP9 genes with interpain A, fadA, and bspA involved in OSCC cases The results indicate that the species specific bacteria may play a role in triggering chronic inflammation in OSCC patients. Therefore, alteration in the gene expression through the dental microbiome could be used as an alternative target in the clinical practice to detect OSCC.

Effect of Two Dental Restorative Materials on Adhesion and Molecular Structure of Oral Bacteria

Dental restorative materials are widely used to repair teeth and dentition defects. However, the dental restorative materials tend to react with oral bacteria when they are exposed to oral conditions, which leads to a change in the oral microecology. Herein, we have employed molecular dynamics simulations to investigate the interaction between different dental restorative materials and oral bacteria. It was found that the staphylococcal protein A (SPA) is more likely to attach on the surface of silicon carbide (SiC) substrate than hematite (Fe₂O₃) substrate surface. Furthermore, the tightly adhesion and accumulation of SPA on SiC surface changes the molecular structure of SPA, which will induce a change in the oral microecology. This study has demonstrated that the adhesion and molecular structure of oral bacteria is strongly dependent on dental restorative materials by molecular dynamics simulations, and Fe₂O₃ is more suitable to be a dental restorative material. It is therefore believed that molecular dynamics simulations can be used to further screen suitable materials for oral rehabilitation.

Determination of the infection rate of dental caries-causing bacteria in adolescents by a real-time PCR test method

Determination of the infection rate of dental caries-causing bacteria in adolescents by a real-time PCR test method

Toothbrushing for Dependent Neurological Patients in the Intensive Care Unit

Toothbrushing for Dependent Neurological Patients in the Intensive Care Unit

P0371DENTAL CARIES INDUCED BY CNM-POSITIVE STREPTOCOCCUS MUTANS DERIVED FROM IGA NEPHROPATHY PATIETNS IN RATS INDUCED GLOPERULONEPHRITIS LIKE IGA NEPHROPATHY

Abstract Background and Aims IgA nephropathy (IgAN) is one of most common primary glomerulonephritis, whose pathogenesis had remained unclear. We had reported that Cnm-(+)Streptococcus mutans, a kinds of major dental caries bacteria. Cnm-(+)S. mutans had strong collagen binding ability, resulting in high pathogenicity. We reported that the prevalence of Cnm-(+)S. mutans in IgA nephropathy is significantly higher than that in control (Misaki-T et al, Clin Exp Nephrol 2015; 19:844-50), and that Cnm-(+)S. mutans in IgA nephropathy was associated with proteinuria (Misaki-T et al, Sci Rep 2016). We also reported C.rectus and S. mutans increased proteinuria synergistically (Misaki-T et al, Nephron, 2018). In this point, there is no direct evidence that Cnm-(+)S. mutans could induce IgA nephropathy. In this study, we evaluated the renal lesions in rats which had dental caries induced by Cnm-(+)S. mutans derived from IgA nephropathy patient to confirm the pathogenesis of IgA nephropathy like lesions induced by Cnm-(+)S mutans. Method Cmn-(+)S. mutans from saliva of IgA nephropathy patients was orally administrated into 4 weeks old male Sprague-Dawley rats. Addition of sugar to water had been kept during study period to develop dental carits. At week 34 after the infection, blood, urine, and kidney samples were evaluated. Kidney samples were stained by Periodic Acid-Schiff (PAS), IgA, C3. Historical evaluation by electron microscope analysis was also performed. Results At week 34, plaque score and dental caries score in infectious rats significantly elevated, compared with control rats (P&amp;lt;0.001) (Figure 1). These findings suggested Cmn-(+)S. mutans from IgA nephropathy patients induced dental caries in rats. PAS staining revealed the significant mesangial proliferation. At week 34, the prevalence of IgA deposition in infections rats was higher than that in control rats (52.4% vs 4%), and the prevalence of C3 deposition in infectious rats was also higher than that in control rats (42% vs 11%) (Figure 2). Incidence of hematuria was also significantly higher in dental caries group than control. Electron microscopy analysis revealed high dense deposit in mesangial areas. Conclusion Cmn-(+)S. mutans from saliva of IgA nephropathy patients could induce IgA-dominant infection-associated glomerulonephritis, or IgA nephropathy.

Salivary markers of oxidative stress and periodontal pathogens in patients with periodontitis from Santander, Colombia.

Introduction: Periodontitis affects more than 20% of the Latin American population. Oxidative markers are associated with greater progression of periodontitis; therefore, its role in pathogenesis should be studied.Objective: To determine the prevalence of the main oral bacteria and viruses associated with periodontitis and estimate the total antioxidant capacity and lipid peroxidation in saliva from patients with periodontitis.Materials and methods: We conducted systemically a cross-sectional study in 101 healthy subjects, 87 of whom had been diagnosed with periodontitis (P), according to the criteria of the Centers of Disease Control and Prevention and the American Academy of Periodontology, and 14 without periodontal pockets as controls (C). In subgingival samples, major viruses and dental pathogenic bacteria were identified using PCR techniques. The levels of total antioxidant capacity and malon-di-aldehyde (MDA) were determined by spectrophotometry in samples of unstimulated saliva.Results: The mean of periodontal depth pocket and clinical attachment loss in patients with periodontitis was 5.6 ± 1.7 and 6.1 ± 3.1 mm, respectively. The most prevalent microorganisms were Aggregatibacter actinomycetemcomitans (32.5%) and Porphyromonas gingivalis (18.6%). The patients from rural areas showed a higher percentage of A. actinomycetemcomitans (urban: 17.9% vs. rural: 48.9%, p=0.0018). In patients with periodontitis, the frequency of EBV, HSV1 & 2, and HCMV genes was 2.3%. Periodontitis patients had higher levels of MDA (P: 2.1 ± 1.5; C: 0.46 ± 0.3 µmol/g protein; p=0.0001) and total antioxidant capacity (P: 0.32 ± 0.2; C: 0.15 ± 0.1 mM; p< 0.0036). Oxidative markers showed no modifications due to the presence of periodontopathic bacteria.Conclusions: Aggregatibacter actinomycetemcomitans was the most prevalent bacteria; its presence did not modify the levels of oxidative markers in the saliva of patients with periodontitis.