PCR-based identification of bacteria associated with endodontic infections

Impact of root canal disinfection on the bacteriome present in primary endodontic infection: A next generation sequencing study

AIM

To investigate the bacteriome present in teeth with primary endodontic infection (PEI) and apical periodontitis (AP) and to determine quantitatively and qualitatively the impact of chemomechanical preparation (CMP) using 2.5% sodium hypochlorite NAOCl on the bacteriome found in PEI with AP using the Illumina MiSeq platform.

METHODOLOGY

Thirty-six paired samples from 18 patients were successfully sequenced and analysed. Samples were collected at two sampling times: before (s1) and after (s2) CMP using 2.5% NaOCl. The DNA was extracted from s1 and s2 samples and quantified using quantitative PCR (qPCR). All 36 samples were sequenced using the Illumina MiSeq platform. Raw V3-V4 amplicon sequencing data were processed with the DADA2 pipeline to generate amplicon sequence variants (ASVs). Alpha diversity metrics representing abundance (Chao1) and diversity and evenness (Shannon, Simpson) were computed. The paired-sample Wilcoxon's test was used to compare alpha diversity metrics and qPCR counts between s1 and s2. The PERMANOVA method (with 999 permutations) was applied to compare community composition between sample types (s1 versus s2) and between patient IDs. ALDEx2 (ANOVA-like differential expression tool for high-throughput sequencing data) to investigate differentially abundant taxa between s1 and s2. A paired-sample Wilcoxon's test was used to compare alpha diversity metrics and qPCR counts between s1 and s2.

RESULTS

The qPCR counts were significantly higher in s1 compared to s2 (p = .0007). The Chao1 index indicated no difference in alpha diversity (p < .7019); whereas Shannon (p = .0056) and Simpson (p = .02685) indexes showed higher values in s2. The PERMANOVA test using Adonis2 showed a significant effect of sample time on community composition (R2 = .0630, p = .012). Patient ID also showed a significant effect on community composition (R2 = .6961, p = .001). At the genus level, Dialister, Mogibacterium, Prevotella, and Olsenella were differentially enriched at s1, while Actinomyces, Stenotrophomonas_unclassified, Enterococcus_unclassified, and Actinomyces_unclassified were differentially enriched in s2.

CONCLUSION

The bacteriome present in teeth with PEI with AP is complex and diverse. CMP using 2.5% NaOCl showed a high quantitatively and qualitatively disinfectant impact on the bacteriome present in PEI with AP.

Is SWEEPS better than PUI in reducing intracanal bacteria and inflammation in cases of apical periodontitis?

To evaluate the efficacy of SWEEPS mode of the Er: YAG laser(SL) and passive ultrasonic irrigation(PUI) in the eradication of microorganisms and in the inflammation detection by IL-1β. Thirty patients with chronic apical periodontitis(AP) were allocated into two groups: Group SL-SWEEPS laser activated irrigation(n = 15) and Group PUI-passive ultrasonic irrigation(n = 15). Bacteriological samples were taken before(S1) and after chemomechanical preparation(S2), and then after final irrigation activation(S3). The levels of total bacteria and Streptococci were measured by means of PCR. Blood samples were collected before and 3rd day after treatment. Enzyme-linked immunosorbent assay was used to measure the levels of IL-1β. The bacterial reduction showed no differences between groups after chemo-mechanical treatment and after irrigant activation(p = 0.590). Post-treatment IL-1β levels were lower than pretreatment levels in both groups(p < 0.001). SL or PUI application in addition to chemomechanical preparation has similar effects on total bacterial level and inflammation detected by IL-1β in patients with AP.

Interplay between diabetes mellitus and periodontal/pulpal-periapical diseases

This longevity of life expectancy has indirectly led to an increase in the number of chronic diseases such as periodontitis, apical periodontitis (AP), and diabetes mellitus (DM) in the aging society, thus affecting people's quality of life. There is an interaction between periodontitis/AP and DM with a two-way relationship. Although type 1 and 2 diabetes (T1DM, T2DM) have different etiologies, glycemic control may affect the infection, inflammation and tissue healing of periodontitis and AP. Non-surgical periodontal treatment may influence the glycemic control as shown by decrease of HbA1c level in T2DM patient. However, the effect of periodontal treatment on glycemic control in T1DM and root canal treatment/apical surgery on T1DM and T2DM patients awaits investigation. DM may affect the periodontal and periapical tissues possibly via altered oral microbiota, impairment of neutrophils' activity and host immune responses and cytokine production, induction of oxidative stress etc. While periodontitis associated systemic inflammation and hyperlipidemia is suggested to contribute to the control of T2DM, more intricate studies are necessary to clarify the detailed mechanisms. The interactions between DM (T1DM and T2DM) and periodontitis and AP are therefore reviewed to provide a basis for the treatment of subsequent patients with pulpal/periodontal disease and diabetes. A two-pronged approach of medical and dental treatment is needed for the management of these patients, with emphasis on blood glucose control and improving oral hygiene and periodontal maintenance care, to ensure the best treatment outcome.

The effect of a preparation containing glycocholic acid on the biocidal efficacy of sodium hypochlorite in a biofilm laboratory model

This study assessed the antimicrobial effect of sodium hypochlorite (NaOCl) mixtures combined with Keratobacter (KB) using an engineered biofilm root canal model. Clinical and reagent grade NaOCl were mixed with KB (9:1-vol/vol) to assess pH values over 1 min to select the ideal solution with a pH just below the pKa of hypochlorous acid. The samples were randomly divided into five groups: 1% and 4% NaOCl reagents, a mixture of NaOCl:KB using 1% and 4% NaOCl reagents and distilled water. Outcome measures were colony-forming units (CFUs/mL) and positive/negative cultures. No significant differences were observed in the pairwise comparisons between 1%, 4% NaOCl and 4% NaOCl+KB for the outcome CFUs/mL. Only 4% NaOCl presented with negative cultures in all samples, whereas 1% NaOCl and 4% NaOCl+KB had similar results (54% vs. 40%). The addition of KB has a limited effect on the antimicrobial efficacy of 4% NaOCl in this laboratory model.

An Ex-Vivo Model for Investigating Bacterial Extrusion from Infected Root Canals during Masticatory Function

INTRODUCTION

The extrusion of bacteria from infected root canals may lead to increase in symptoms, expansion of periapical lesions, and contribution to systemic diseases. The aim of this study is to investigate a potential proof-of-concept model to study the extent to which bacteria can escape from infected root canals under dynamic loading (simulated chewing).

METHODS

The study was completed in 2 experiments performed at 2 institutions. Biofilms of Streptococcus intermedius in the first experiment and S. intermedius and Actinomyces naeslundii were allowed to grow in root canals of single-rooted extracted teeth for 3 weeks. The roots of the teeth were suspended in a small chamber containing dental transport medium and were mounted on a lower sample holder of a chewing simulator. In the experimental group, simulated chewing cycles equivalent to 1 year of function were conducted, and then bacterial migration was quantified and compared with stationary teeth.

RESULTS

All experimental samples of the loading group revealed bacterial penetration in both experiments. Several of the unloaded samples revealed no bacterial penetration. In the first experiment, a significantly higher number of bacteria were able to escape into the periapex of the loaded group compared with the unloaded group (P = .017). In the second experiment, there was no significant difference between the 2 bacterial species used in the amount of extruded bacteria; however, there was a highly significant effect for occlusal loading (P = .0001).

CONCLUSIONS

The potential for occlusal forces to enhance bacterial extrusion from infected root canals should be further explored.

A novel experimental model to investigate fungal involvement shows expression of Dectin-1 in periapical lesion pathogenesis

BACKGROUND

Candida albicans is linked to persistent endodontic lesions. However, the recognition receptor that identifies it is not explored previously.

OBJECTIVES

The aim of this study was to (1) establish a zymosan-induced model of apical periodontitis in mouse, (2) observe the expression of Dectin-1 and its possible relationship with toll-like receptor (TLR) 2 and (3) observe relationship between Osteopontin (OPN) and inflammatory cytokines.

METHODS

A total of 138 Naval Medical Research Institute (NMRI) mice were randomly divided into; Experimental Group n = 69 and Zymosan Group n = 69. Periapical periodontitis was developed in right maxillary molar. The animals were sacrificed at 7, 21 and 42 days. Bone blocks containing the mesial root (n = 15 for qRT-PCR, n = 45 for enzyme-linked immune sorbent assay (ELISA)) were collected for mRNA expression and ELISA. While whole maxilla (n = 3 from each time interval) were used for histology and immunohistochemical analysis. One way analysis of variance (ANOVA) and Tuckey's posthoc was used for statistical analysis at p ≤ .05.

RESULTS

TLR-2, Dectin-1 and TLR4-positive cells was detected at all time intervals in both groups. A strong positive correlation was observed between TLR-2 and Dectin-1 in both lesions (regular r = .680, p = .015, zymosan (r = .861, p < .001)). A significant correlation was found between OPN and tumour necrosis factor-alpha (TNF-α) in zymosan lesion (r = .827, p = .001).

CONCLUSIONS

Immune cells of inflamed periapical tissue expressed Dectin-1 receptor in response to the microbial challenge from infected root canals and showed positive correlation with TLR-2 and OPN suggesting a possible receptor collaboration mediated by OPN. The expression of OPN and TNF-α showed positive correlation in response to fungal antigen, indicating a possible relationship.

Prevalence of Fusobacterium Species in Endodontic Infections Detected With Molecular Methods: Systematic Review and Meta-Analysis

INTRODUCTION

Endodontic infections are polymicrobial; however, investigating the role of bacterial species is critical because they may influence pathogenesis, the development of symptoms, or the persistence of disease. This systematic review aimed to determine the prevalence of Fusobacterium species and its association with different types of endodontic infections.

METHODS

MEDLINE (Ovid), PubMed, Scopus, Web of Science, and Cochrane Library databases were used as electronic databases to retrieve relevant studies. The studies were evaluated for eligibility criteria, and the certainty in evidence and risk of bias were evaluated using critical appraisal tools for prevalence studies from the Joanna Briggs Institute. Forty studies were selected for meta-analysis and statistically analyzed for the relationship between the prevalence of Fusobacterium species and both the presence of symptoms and the type of infections (primary vs secondary/persistent) using meta-regression analysis.

RESULTS

The prevalence of Fusobacterium spp. in endodontic infections ranged from 3%-100% (mean = 42.51%) in the 40 included studies. Calculated confidence intervals indicated that the presence of Fusobacterium spp. was not statistically associated with the presence of symptoms or with the type of infections (the set of 2 predictors was not significant; P < .05).

CONCLUSIONS

The prevalence of Fusobacterium infection, which was identified with molecular methods, was not significant for overall regression using both predictors (ie, symptoms [symptomatic vs asymptomatic] and types of infections [primary vs secondary/persistent]).

Antimicrobial FiteBac® K21 promotes antimicrobial Potency and wound healing

Objectives

Successful root canal therapy is dependent on the efficacy of complete instrumentation and adequate use of chemical irrigant to eliminate the biofilm from dentin surface. The aim of the study was to examine antibiofilm and antimicrobial effectiveness of newly formulated Quaternary ammonium silane (QAS/also codenamed K21; against Fusobacterium nucleatum (F. nucleatum) and Enterococcus faecalis (E. faecalis) biofilm on radicular dentin with evaluation of the anti-inflammatory consequence in vivo.

Methods

Fourier Transform Infrared Spectroscopy (FTIR) was performed after complete hydrolysis of K21 solution. Human teeth were inoculated with biofilms for 7-days followed by treatment with various irrigants. The irrigant groups were Sodium hypochlorite [NaOCl (6%)], Chlorhexidine [CHX (2%)], K21 (0.5%), K21 (1%) and Saline. Scanning electron microscopy (SEM) was performed for biofilm and resin-dentin penetration. Transmission Electron Microscopy (TEM) of biofilms was done to evaluate application of K21. For in vivo evaluation, Albino wistar rats were injected subcutaneously and sections were stained with haematoxylin/eosin. Macrophage, M1/M2 expression were evaluated along with molecular simulation. Raman measurements were done on dried biofilms.

Results

FTIR K21 specimens demonstrated presence of ethanol/silanol groups. Raman band at 1359 cm-1 resemble to -CH2- wagging displaying 29Si atoms in Nuclear Magnetic Resonance (NMR). 0.5%K21 showed cells exhibiting folded membranes. SEM showed staggering amount of resin tags with 0.5% K21 group. TEM showed membrane disruption in K21-groups. K21 groups were initially irritant, which subsided completely afterwards showing increased CD68. K21 and MMP/collagen complex was thermodynamically favourable.

Conclusion

K21 root canal irrigant was able to penetrate bacterial wall and can serve as a potential irrigant for therapeutic benefits. Expression of M2 polarized subsets showed K21 can serve in resolving inflammation and potentiate tissue repair.

Retrospective analysis of Porphyromonas gingivalis in patients with nasopharyngeal carcinoma in central China

Little is known about the presence and possible role of Porphyromonas gingivalis (P. gingivalis) in nasopharyngeal carcinoma (NPC), its co-infection with Epstein-Barr virus (EBV), or their association with clinical characteristics of patients with NPC in Central China, where NPC is non-endemic. A total of 45 NPC formalin-fixed paraffin-embedded (FFPE) tissues were retrospectively analyzed using immunohistochemistry (IHC) and a nested PCR combined with DNA sequencing to detect the presence of P. gingivalis, and using reverse transcription-quantitative PCR to detect the presence of EBV. Clinical data including EBV and P. gingivalis status were associated with overall survival (OS). All tumors were undifferentiated, non-keratinizing carcinomas, of which 40/45 (88.9%) were positive for EBV (EBV⁺), 26/45 (57.8%) were positive for P. gingivalis (by IHC), and 7/45 (15.6%) were positive for P. gingivalis DNA (P. gingivalis ⁺). All seven P. gingivalis DNA-positive NPCs were co-infected with EBV. The 5-year survival rates of the patients with EBV^-/P. gingivalis ^-, EBV⁺/P. gingivalis ^-, and EBV⁺/P. gingivalis ⁺ tumors were 60.0% (3/5), 39.4% (13/33) and 42.9% (3/7), respectively. No significant difference was found between the OS of NPC patients among the different infection groups (P=0.793). In conclusion, to the best of our knowledge, this is the first study to describe and confirm the presence of P. gingivalis in FFPE tissues from patients with NPC. P. gingivalis was found to co-exist with EBV in NPC tumor tissues, but is not etiologically relevant to NPC in non-endemic areas, such as Central China.

Eco-friendly bioremediation of pollutants from contaminated sewage wastewater using special reference bacterial strain of Bacillus cereus SDN1 and their genotoxicological assessment in Allium cepa

The present study aimed to assess the Bacillus cereus SDN1 native bacterium's ability to clean up contaminated or polluted water. The isolated bacterium was identified by its morphological and biochemical characteristics, which were then confirmed at the genus level. Furthermore, the isolated B. cereus (NCBI accession No: MW828583) was identified genomically by PCR amplifying 16 s rDNA using a universal primer. The phylogenetic analysis of the rDNA sequence was analyzed to determine the taxonomic and evolutionary profile of the isolate of the previously identified Bacillus sp. Besides, B. cereus and the bacterial consortium were treated using sewage wastewater. After 15 days of treatment, the following pollutants or chemicals were reduced: total hardness particles removal varied from 63.33 % to 67.55 %, calcium removal varied from 90 % to 93.33 %, and total nitrate decreased range from 37.77 % to 22.22 %, respectively. Electrical conductivity ranged from 1809 mS/cm to 2500 mS/cm, and pH values ranged from 6.5 to 8.95. The outcome of in-situ remediation results suggested that B. cereus has a noticeable remediation efficiency to the suspended particles. A root tip test was also used to investigate the genotoxicity of treated and untreated sewage-contaminated waters on onion (Allium cepa) root cells. The highest chromosomal aberrations and mitotic inhibition were found in roots exposed to contaminated sewage water, and their results displayed chromosome abnormalities, including disorganized, sticky chain, disturbed metaphase, chromosomal displacement in anaphase, abnormal telophase, spindle disturbances, and binucleate cells observed in A. cepa exposed to untreated contaminated water. The study can thus be applied as a biomarker to detect the genotoxic impacts of sewage water pollution on biota. Furthermore, based on an identified bacterial consortium, this work offers a low-cost and eco-favorable method for treating household effluents.

Taxonomic abundance in primary and secondary root canal infections

AIM

To evaluate the root canal microbiome composition in cases of primary and secondary apical periodontitis.

METHODOLOGY

Thirty-nine samples from patients with primary root canal infections obtained before root canal treatment, and 40 samples obtained during root-end resection procedures from previously filled cases with apical periodontitis were evaluated using 16S rRNA next-generation sequencing analysis (NGS). Demographic and clinical factors included age, sex, infection type, percussion sensitivity, and presence of pain. Differences in abundances of genera were evaluated using Kruskal-Wallis test. Alpha and beta diversity indices were calculated using mothur. The Shannon and Chao1 indices were used to measure alpha diversity. The Bray-Curtis dissimilarity was used to measure beta diversity. Differences in community composition were evaluated using analysis of similarity (ANOSIM) with Bonferroni correction for multiple comparisons.

RESULTS

Significantly fewer operational taxonomic units values were observed from samples from secondary infections (p < .0001). While no significant differences were observed in the Chao 1 index between primary and secondary infections, the Shannon alpha diversity was significantly lower in secondary relative to primary infections (p = .008). Among samples, sex, age (adult vs. older adult), percussion sensitivity, and presence of pain all showed no significant effects on community composition via an analysis of similarity (ANOSIM). However, community composition was significantly different depending on whether the sample was from a primary or secondary infection (R = .051, p = .03). Nine microbial genera comprised the predominant taxa observed among samples (>3.3%) and included Parvimonas, Fusobacterium, Campylobacter, Arachnia, Eubacterium, Prevotella, Peptostreptococcus, Fretibacterirum, and Pseudoramibacter. Significantly greater relative abundances of Prevotella, Peptostreptococcus, Veillonella, Lactucaseibacillus, and Dialister were observed in primary infections.

CONCLUSIONS

Primary endodontic infections are more diverse than secondary infections. The microbial composition is not associated with the clinical manifestations of apical periodontitis.

Evaluation of PCR primers to identify Porphyromonas endodontalis in apical periodontitis clinical samples

We aimed to evaluate whether two commonly used PCR primers are effective to identify P. endodontalis and discriminate from other prevalent black-pigmented bacteria in apical periodontitis (AP). Endodontic canal samples from patients with asymptomatic AP (n = 20) were collected and cultured in anaerobiosis. Two primer sets to detect P. endodontalis were selected from the literature and first analyzed for their specificity in silico; and then tested on clinical isolates in vitro and finally, in apical exudates ex vivo. The identity of P. endodontalis was verified by PCR and Sanger sequencing with universal primers for bacterial V3-V6 regions 16S rDNA. Only one primer set showed specificity only for P. endodontalis clones in silico and also was specific for P. endodontalis in vitro and ex vivo.

Microbiome Changes During Regenerative Endodontic Treatment Using Different Methods of Disinfection

INTRODUCTION

The purpose of this study was to characterize qualitatively and quantitatively the changes in the endodontic microbiome, in teeth with necrotic pulp, open apexes and apical periodontitis, with three antimicrobial protocols, undertaken in a multicenter clinical trial.

METHODS

Microbiological samples were collected from 116 RET teeth, and 97 qualified for inclusion. The teeth were randomly divided into three treatment groups: apexification (APEX), regeneration (REGEN) and revascularization (REVASC), all in two appointments. The group variables in the first appointment irrigants, and second appointment irrigants and medicaments were as follows: APEX: 5.25-6% NaOCl, 5.25-6% NaOCl + 17% EDTA and calcium hydroxide; REGEN: 1.25% NaOCl, 17% EDTA and 0.1 mg/mL triple antibiotic paste (TAP); and REVASC 5.25% NaOCl, saline and 1g/mL TAP, respectively. Sampling was done upon access (S0), after irrigation in the first appointment (S1), and after using medication and irrigation in the second appointment (S2).

RESULTS

Quantitative PCR analysis of the 16S rRNA gene showed significant reduction in bacterial load from S0 to S2 in all groups; however, the APEX and REVASC groups had significantly less residual DNA than the REGEN group (p=0.0045). The relative abundance of Bacteroidetes, Fusobacteria, Spirochaetes and Synergistetes were reduced with the treatment rendered. However, relative abundance of Firmicutes and Actinobacteria was not changed, and that of Proteobacteria increased. LEfSe analysis showed that reduction in bacterial taxa was more in REVASC than APEX which in turn was more than in REGEN.

CONCLUSION

Enhanced antimicrobial protocols lead to better reduction in quantitative and qualitative parameters of the endodontic microflora.

Periodontal status and the incidence of selected bacterial pathogens in periodontal pockets and vascular walls in patients with atherosclerosis and abdominal aortic aneurysms

The aim of the study was to examine the periodontal status of patients with atherosclerosis and abdominal aortic aneurysms. The occurrence of 5 periodontopathogens was evaluated in periodontal pockets and atheromatous plaques together with specimens from pathologically changed vascular walls of aortic aneurysms. The study comprised 39 patients who qualified for vascular surgeries. Patients with periodontitis and concomitant atherosclerosis or aneurysms were enrolled in the study. Periodontal indices were evaluated, and subgingival plaque samples were examined together with atheromatous plaques or specimens from vascular walls to identify, by polymerase chain reaction (PCR), the following periodontopathogens: Porphyromonas gingivalis, Tanarella forsythia, Aggregatibacter actinomycetemcomitans, Prevotella intermedia and Treponema denticola. The majority of patients had chronic severe generalized periodontitis in stages III and IV. Laboratory investigations showed the occurrence of one or more of the five targeted periodontopathogens in 94.6% of the periodontal pockets examined. Of the examined periodontopathogens, only Porphyromonas gingivalis was confirmed in 1 atheromatous plaque sample collected from the wall of an aortic aneurysm. Therefore, the occurrence of this bacterium in these vessels was considered to be occasional in patients with chronic periodontitis.

Bioactive potentiality of secondary metabolites from endophytic bacteria against SARS-COV-2: An in-silico approach

Five endophytic bacterial isolates were studied to identify morphologically and biochemically, according to established protocols and further confirmed by 16S rDNA Sanger sequencing, as Priestia megaterium, Staphylococcus caprae, Neobacillus drentensis, Micrococcus yunnanensis, and Sphingomonas paucimobiliz, which were then tested for phytohormone, ammonia, and hydrolytic enzyme production. Antioxidant compounds total phenolic content (TPC), and total flavonoid content (TFC) were assessed by using bacterial crude extracts obtained from 24-hour shake-flask culture. Phylogenetic tree analysis of those identified isolates shared sequence similarities with the members of Bacillus, Micrococcus, Staphylococcus, and Pseudomonas species, and after GenBank submission, accession numbers for the nucleotide sequences were found to be MW494406, MW494408, MW494401, MW494402, and MZ021340, respectively. In silico analysis was performed to identify their bioactive genes and compounds in the context of bioactive secondary metabolite production with medicinal value, where nine significant bioactive compounds according to six different types of bioactive secondary metabolites were identified, and their structures, gene associations, and protein-protein networks were analyzed by different computational tools and servers, which were reported earlier with their antimicrobial, anti-infective, antioxidant, and anti-cancer capabilities. These compounds were then docked to the 3-chymotrypsin-like protease (3CLpro) of the novel SARS-COV-2. Docking scores were then compared with 3CLpro reference inhibitor (lopinavir), and docked compounds were further subjected to ADMET and drug-likeness analyses. Ligand-protein interactions showed that two compounds (microansamycin and aureusimine) interacted favorably with coronavirus 3CLpro. Besides, in silico analysis, we also performed NMR for metabolite detection whereas three metabolites (microansamycin, aureusimine, and stenothricin) were confirmed from the 1H NMR profiles. As a consequence, the metabolites found from NMR data aligned with our in-silico analysis that carries a significant outcome of this research. Finally, Endophytic bacteria collected from medicinal plants can provide new leading bioactive compounds against target proteins of SARS-COV-2, which could be an effective approach to accelerate drug innovation and development.

Increase in Bifidobacterium is a characteristic of the difference in the salivary microbiota of pregnant and non-pregnant women

Background

The establishment of symbiotic microbiota in pregnant women is important for both the mother and her offspring. Little is known about the salivary symbiotic bacteria in pregnancy, and analysis of composition of microbiome (ANCOM) is useful to detect small differences in the number of bacteria. The aim of this study was to investigate the differences in the salivary bacteria between healthy pregnant and non-pregnant women using ANCOM.

Methods

Unstimulated saliva samples were collected from 35 healthy pregnant women at 35 weeks gestation and 30 healthy non-pregnant women during menstruation. All participants underwent a periodontal examination. Estradiol and progesterone levels were examined by enzyme-linked immunosorbent assay. DNA extracted from the saliva was assessed by 16S ribosomal RNA amplicon sequencing and real-time PCR.

Results

Salivary estradiol and progesterone levels were significantly increased in pregnant women. The alpha and beta diversities were higher in pregnant women than in non-pregnant women. The largest effect size difference noted when the microbiota of the pregnant and non-pregnant women were analyzed was that for Bifidobacteriales. Levels of Bifidobacterium dentium, but not of Bifidobacterium adolescentis, were significantly increased in pregnant women, and the levels were significantly correlated with progesterone concentration.

Conclusion

The results suggest that Bifidobacterium and progesterone levels are elevated in the saliva of healthy pregnant women compared with non-pregnant women.

CpG Single-Site Methylation Regulates TLR2 Expression in Proinflammatory PBMCs From Apical Periodontitis Individuals

Introduction

Apical periodontitis (AP) is a common oral disease caused by the inflammatory destruction of the periapical tissues due to the infection of the root canal system of the tooth. It also contributes to systemic bacterial translocation, where peripheric mononuclear blood cells (PBMCs) can act as carriers. Toll-like receptor (TLR) 2 mediates the response to infection and activates inflammatory responses. DNA methylation can be induced by bacteria and contributes to the modulation of this response. Despite the evidence that supports the participation of PBMCs in immune-inflammatory disorders, the inflammatory profile and epigenetic regulatory mechanisms of PBMCs in AP individuals are unknown.

Aim

To determine TLR2 gene methylation and inflammatory profiles of PBMCs in AP.

Methods

Cross-sectional exploratory study. Otherwise, healthy individuals with AP (n=27) and controls (n=30) were included. PMBCs were isolated by a Ficoll gradient, cultured for 24 hours, and both RNA and DNA were extracted. DNA was bisulfite-treated, and specific sites at the promoter region of the TLR2 gene were amplified by qPCR using validated primers. To verify its amplification, agarose gels were performed. Then, the PCR product was sequenced. mRNA expression of TLR2 was determined by qPCR. The soluble levels of 105 inflammatory mediators were first explored with Proteome Profiler Human Cytokine Array Kit. Consequently, tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-10, IL-6Rα, IL-1β, and IL-12p70 levels were measured by Multiplex assay.

Results

PBMCs from individuals with AP demonstrated a proinflammatory profile showing higher soluble levels of TNF-α, IL-6, and IL-1β compared to controls (p<0.05). Higher TLR2 expression and higher global methylation pattern of the promoter region of the gene were found in AP compared to controls (p<0.05). The CpGs single-sites at positions -166 and -146 were completely methylated, while the site -102 was totally unmethylated, independently of the presence of AP. DNA methylation of CpG single-sites in positions -77 and +24 was positively associated with TLR2 expression.

Conclusions

PBMCs from AP subjects show a hyperinflammatory phenotype and TLR2 upregulation in association with single CpG-sites’ methylation from the TLR2 gene promoter, thereby contributing to a sustained systemic inflammatory load in individuals with periapical endodontic diseases.

Microbial analysis of endodontic infections in teeth with post-treatment apical periodontitis before and after medication

This study aimed to determine the intraradicular microbiota of previously root canal-treated teeth with apical periodontitis and to investigate the antibacterial effectiveness of different intracanal medicaments. Sixteen patients with post-treatment apical periodontitis were allocated into two groups according to the intracanal medicament used: calcium hydroxide (CH) and 2% chlorhexidine gluconate gel (CHX) group. Total bacterial loads, as well as the amount of Enterococcus faecalis (E. faecalis) were determined before (S1) and after (S2) chemomechanical preparation and finally, after intracanal medication (S3) by means of ddPCR. The unpaired t test was used to compare parametric. S3-total bacteria copy number of the CH group was lower than the CHX group (p < 0.05). There was no statistical difference between the CHX- and the CH groups in terms of E.faecalis copy number (p > 0.05). But in terms of total bacteria, CH is better than CHX. Consequently, CH can be used to optimise the antibacterial efficiency of chemomechanical preparation in previously root canal-treated teeth with apical periodontitis.

Relationships between Solobacterium moorei and Prevotella intermedia in subgingival microbiota of periodontitis patients with halitosis: A preliminary study using qPCR

Objective

Material & methods

Results

Conclusion

Present status and future directions - microbiology of endodontic infections

Apical periodontitis has a microbial aetiology and is one of the most common inflammatory diseases that affect humans. Fungi, archaea and viruses have been found in association with apical periodontitis, but bacteria are by far the most prevalent and dominant microorganisms in endodontic infections. Bacterial infection of the root canal system only occurs when the pulp is necrotic or was removed for previous treatment. In some specific cases, including acute and chronic abscesses, the bacterial infection may reach the periradicular tissues. Intracanal bacteria are usually observed as sessile multispecies communities (biofilms) attached to the dentinal root canal walls. Infection in the main root canal lumen can spread to other areas of the root canal system. Although more than 500 bacterial species have been detected in endodontic infections, a selected group of 20 to 30 species are most frequently detected and may be considered as the core microbiome. There is a high interindividual variability in the endodontic microbiome in terms of species composition and relative abundance. Obligate anaerobic species are more abundant in the intraradicular bacterial communities of teeth with primary apical periodontitis, while both anaerobes and facultatives dominate the communities in post-treatment apical periodontitis. Bacterial interactions play an essential role in determining the overall virulence of the community, which has been regarded as the unit of pathogenicity of apical periodontitis. This article reviews the microbiologic aspects of endodontic infections and provides perspectives for future research and directions in the field.

A critical analysis of research methods and experimental models to study the root canal microbiome

Endodontic microbiology deals with the study of the microbial aetiology and pathogenesis of pulpal and periradicular inflammatory diseases. Research in endodontic microbiology started almost 130 years ago and since then has mostly focussed on establishing and confirming the infectious aetiology of apical periodontitis, identifying the microbial species associated with the different types of endodontic infections and determining the efficacy of treatment procedures in eradicating or controlling infection. Diverse analytical methods have been used over the years, each one with their own advantages and limitations. In this review, the main features and applications of the most used technologies are discussed, and advice is provided to improve study designs in order to properly address the scientific questions and avoid setbacks that can compromise the results. Finally, areas of future research are described.

Nonclinical research areas of future importance for clinical therapies: Exploring the concepts of nonlinearity in dentistry

Linear system analysis has been dominating medical and dental research, and most of the research achievements in these fields have come from applying a reductionist view of nature. However, biologic systems are fundamentally nonlinear with highly composite dynamics made up of numerous interacting elements and feedback loops, therefore studying them as linear models may not result in an accurate representation of their true features. The authors reviewed and utilized some of the principles of chaos and nonlinearity and extended them to clinical dentistry, from cracked tooth and flare-up after root canal procedures to the outcome of clinical treatments. Utilization of the concepts of chaos and sensitive dependence on initial conditions, and the concepts of self-organization, stigmergy, and fractals may help us to understand some of the puzzles that have not been solved by conventional linear models. The goal of this paper is to present some areas within nonclinical research that we believe will have important roles in the development of future clinical examination methods and therapies.

Quantitative Analysis of Candidate Endodontic Pathogens and Their Association with Cause and Symptoms of Apical Periodontitis in a Sudanese Population

Objective:

To investigate the prevalence of key endodontic pathogens and their association with the clinical features and the cause of apical periodontitis.

Methods:

The study population included patients referred to Khartoum Dental teaching Hospital, Sudan for endodontic treatment. Samples were collected from single-rooted teeth carious or traumatised teeth with clinical and radiographic evidence of apical periodontitis. The endodontic pathogens Porphyromonas endodontalis, Fusobacterium nucleatum and Treponema denticola were quantified by real time polymerase chain reaction (qPCR). The prevalence of each species was identified at both a low detection threshold (>50 bacteria) and a high detection threshold (>1000 bacteria).

Results:

75 patients (mean age 30.1 yrs SD 10.1) were included in the analysis. The most prevalent bacterium at both the low and high threshold was F. nucleatum followed by T. denticola at the low threshold and P. endodontalis at the high threshold. There was no association with symptoms at the low detection threshold, but at high threshold P. endodontalis was associated with swelling, adjusted odds ratio (OR), 9.32 95%CI 1.11- 78.66, P=0.04. All species were more prevalent in apical periodontitis due to caries only at the low detection threshold, OR=5.01 (P=0.006) for T. denticola; 4.84 (P=0.01) for F. nucleatum; and 3.62 (P=0.03) for P. endodontalis.

Conclusion:

There was a high prevalence of the F. nucleatum, T. denticola and P. endodontalis in apical periodontitis associated with caries. None of these bacterial were associated with pain but the presence of P. endodontalis at high levels was associated with swelling.

Systemic and Extraradicular Bacterial Translocation in Apical Periodontitis

Apical periodontitis is an inflammatory disease of microbial etiology. It has been suggested that endodontic bacterial DNA might translocate to distant organs via blood vessels, but no studies have been conducted. We aimed first to explore overall extraradicular infection, as well as specifically by Porphyromonas spp; and their potential to translocate from infected root canals to blood through peripheral blood mononuclear cells. In this cross-sectional study, healthy individuals with and without a diagnosis of apical periodontitis with an associated apical lesion of endodontic origin (both, symptomatic and asymptomatic) were included. Apical lesions (N=64) were collected from volunteers with an indication of tooth extraction. Intracanal samples (N=39) and respective peripheral blood mononuclear cells from apical periodontitis (n=14) individuals with an indication of endodontic treatment, as well as from healthy individuals (n=14) were collected. The detection frequencies and loads (DNA copies/mg or DNA copies/μL) of total bacteria, Porphyromonas endodontalis and Porphyromonas gingivalis were measured by qPCR. In apical lesions, the detection frequencies (%) and median bacterial loads (DNA copies/mg) respectively were 70.8% and 4521.6 for total bacteria; 21.5% and 1789.7 for Porphyromonas endodontalis; and 18.4% and 1493.9 for Porphyromonas gingivalis. In intracanal exudates, the detection frequencies and median bacterial loads respectively were 100% and 21089.2 (DNA copies/μL) for total bacteria, 41% and 8263.9 for Porphyromonas endodontalis; and 20.5%, median 12538.9 for Porphyromonas gingivalis. Finally, bacteria were detected in all samples of peripheral blood mononuclear cells including apical periodontitis and healthy groups, though total bacterial loads (median DNA copies/μL) were significantly higher in apical periodontitis (953.6) compared to controls (300.7), p<0.05. Porphyromonas endodontalis was equally detected in both groups (50%), but its bacterial load tended to be higher in apical periodontitis (262.3) than controls (158.8), p>0.05; Porphyromonas gingivalis was not detected. Bacteria and specifically Porphyromonas spp. were frequently detected in endodontic canals and apical lesions. Also, total bacteria and Porphyromonas endodontalis DNA were detected in peripheral blood mononuclear cells, supporting their plausible role in bacterial systemic translocation.

Association of specific microorganisms with endodontic signs and symptoms. A comparative study

Aim

The study aimed to evaluate the association of root canal microorganisms red complex and E. facealis with endodontic clinical signs and symptoms using polymerase chain reaction.

Materials and Methods

Bacterial samples were obtained using sterile paper points from the teeth of 100 subjects divided into two groups; Group I: 50 individuals with primary tooth infections and Group II: 50 individuals with failed endodontic treatment having the secondary infection. DNA extracted from samples was analyzed for endodontic pathogens by using species-specific primers.

Results

The pain was noticed in 66%, (33 of 50 subjects) in primary infection and 60% (30 of 50) in a secondary infection. A statistically significant association between pain and E. faecalis bacteria observed both in primary infection and secondary infection (P < 0.05). Tenderness on percussion was associated with 40% cases in Group I and 70% cases in Group II. The red complex accounted for 94% of cases associated with tenderness on percussion in primary infection while 86% of cases associated with secondary infection with a statistically significant association (P < 0.05).

Conclusion

Prevalence of red complex bacteria and E. faecalis suggested the association of studied bacteria with symptomatic infected pulp and periradicular diseases.

Coupling 16S rDNA Sequencing and Untargeted Mass Spectrometry for Milk Microbial Composition and Metabolites from Dairy Cows with Clinical and Subclinical Mastitis

The internal environment of the cow's udder directly affects the udder health and milk quality. 16S rDNA sequencing and liquid chromatography-mass spectrometry (LC-MS) methods were used to investigate the significant differences in milk microbial diversity and metabolites among cows that are healthy (H) and those suffering from subclinical mastitis (SM) and clinical mastitis (CM). Results uncovered more than 16 and 192 differently abundant microbiota at the phylum and genus levels, respectively, and 673 different levels of metabolites enriched in 20 pathways in milk among the 3 groups. This study revealed the positive relevance between Staphylococcus and Streptococcus and ceramide in milk from CM cows. Similarly, Acinetobacter and Corynebacterium were positively associated with testosterone glucuronide and 5-methyl-tetrahydrofolate, in milk from SM cows. On the basis of the combined analysis of microbiome and metabolome, this study indicated that, apart from the exogenous pathogens, some beneficial symbiotic bacteria, such as Dietzia, Aeromicrobium, Alistipes, and Sphingobacterium, rarely reported in milk have been found to be significantly reduced during mastitis.

PCR-based detection of three anaerobic bacteria associated with endodontic-periodontic lesions in type-2 diabetic and nondiabetic subjects

Aim:

The aim of this study is to clinically isolate and detect three anaerobic bacteria associated with endodontic-periodontal lesions in type-2 diabetic and nondiabetic patients using polymerase chain reaction (PCR).

Materials and Methods:

Sixty patients presenting endodontic-periodontal lesions were divided into two groups. Thirty patients with type-2 diabetics (Group 1) and 30 nondiabetic patients (Group 2) were evaluated for the presence of three anaerobic bacteria. Clinical examinations, periapical radiographs, and microbiological sampling from the canal system and periodontal pockets were performed. Qualitative evaluation of bacteria was performed using a multiplex PCR for Porphyromonas gingivalis and Prevotella intermedia. Statistical analysis was performed using Pearson's Chi-square test and Fischer's exact test.

Results:

Enterococcus faecalis (73.3%) was the predominant bacteria isolated from the root canal in type 2 diabetic patients, followed by P. gingivalis (70%) and P. intermedia (36%) compared to 53.3%, 43.3%, and 23.3%, respectively, among nondiabetic patients. P. gingivalis (73.3%) was the predominant bacteria isolated from periodontal pockets in type II diabetic patients followed by P. intermedia 50% and E. faecalis 30% compared to 36.6%, 33.3%, and 30%, respectively, among nondiabetics. P. gingivalis was detected in the root canal and periodontal pocket in almost similar numbers (70% and 73%), respectively, among type-2 diabetics.

Conclusion:

Detection of P. gingivalis, P. intermedia, and E. faecalis in both root canal and periodontal pocket samples confirm a viable pathway for the spread of infection through dual sites. Since in the present study, P. gingivalis was found to be present in similar numbers in dual sites among type 2 diabetic patients, importance should be given in treating such anaerobic bacteria in immune-compromised patients.

Species-specific genomic sequences for classification of bacteria

Modern bacterial classification relies on genomic relatedness. Genetic variation in bacterial populations present a big challenge for taxonomic classification and recently several bacterial species have been reclassified based on the intra-species genome comparison. These were facilitated by next generation sequencing technologies and advances in genome comparison approaches which led to the rearrangement of diverse bacterial species and revolution in the microbial classification system. One of the outcome of these studies is the development of suitable DNA barcodes as reliable and cost-effective method for identifying various bacterial genera. Towards refining this further, we have applied a genome comparison approach in 1104 bacterial genome assemblies (excluding plasmids) to identify unique genomic segments among intra-species genome assemblies. Using extensive bioinformatics analysis, we have identified species-specific genomic regions and designed unique primers for 100 different species (belonging to 62 genera) which includes 62 pathogenic and 13 opportunistic pathogenic bacterial species and built a database (http://slsdb.manipal.edu/bact/). These species-specific genomic regions will have a major impact on in silico and molecular methods aimed at bacterial classification and identification. These may also serve as better DNA barcodes than the markers currently used for delineation of bacteria and may also find application in various translational research programs.

Identification of microorganisms in irreversible pulpitis and primary endodontic infections with respect to clinical and radiographic findings

OBJECTIVES

The aim of this study was to evaluate the composition of microbiota of irreversible pulpitis and primary endodontic infections with respect to clinical and radiographic findings by performing cultures and 16s rDNA sequencing in Iranian patients.

MATERIAL AND METHODS

In this prospective cross-sectional study, samples were collected from 41 root canals for 4 main groups of patients. Bacterial identification was performed by the polymerase chain reaction (PCR) and 16s rDNA sequencing of aerobic and anaerobic cultivable colonies taken from patients' culture plates. Additionally, the presence of 13 bacterial species and 3 nonbacterial species was also explored using PCR and species-specific primers.

RESULTS

Sixteen microbial species, 1 fungus (Candida albicans), and 1 virus (Herpes simplex virus) were discovered and isolated. Species with the highest prevalence were Dialister invisus (68.3%), Porphyromonas gingivalis (58.8%), Streptococcus salivarius (58.5%), and Treponema denticola (56.1%). Lysinibacillus fusiformis (19.1%) was detected in the root canals for the first time. Candida albicans was seen in 11 cases (26.8%). Herpes simplex virus (HSV) was seen in 4 patients (9.8%).

CONCLUSIONS

Our results suggest that Gram-negative anaerobic oral bacteria are the majority of the microbes in primary endodontic infections. Various combinations of bacterial species were related to different clinical and radiographic conditions. Lysinibacillus fusiformis was detected for the first time in primary endodontic infections.

CLINICAL RELEVANCE

The results of this investigation might help clinicians choose to identify suspected endodontic pathogens in the etiology of each form of pulpal and periradicular diseases to determine the best therapeutic measures.

Microbial Bioremediation of Feather Waste for Keratinase Production: An Outstanding Solution for Leather Dehairing in Tanneries

In leather industries and tanneries, large amount of wastes has been disposed; which polluting water, soil, and atmosphere and causing serious human health problems. In particular, chemical dehairing process of leather industries produces fair amount of toxic wastes. It is, thus, urgently needed to use alternative processes free from pollution. As more than 90% of keratin is contained in feather, it is desirable to develop bioremediation process using keratinolytic microorganisms. In the present investigation, therefore, we first identified Bacillus cereus and Pseudomonas sp. to be able to produce keratinase. Then, the optimization was performed to maximize the keratinase activity with respect to cultivation temperature, pH, and incubation time. Moreover, the effects of metal ions and various substrates on keratinase activity were also investigated. The result indicates that keratinase activity became maximum at 50°C for both strains, whereas the optimal pH was 10.0 for B. cereus and 7.0 for Pseudomonas sp. The highest keratinase activity of 74.66 ± 1.52 U/mL was attained by B. cereus, whereas 57.66 ± 2.52 U/mL was attained by Pseudomonas sp. Enzymatic dehairing efficiency of leathers was also compared with chemical dehairing (Na₂S and CaO), where complete dehairing was achieved by treating them with crude keratinase. Partial enzyme purification was performed by acetone precipitation. Batch cultivation of B. cereus using 1 L fermentor indicates a potential candidate for large-scale keratinase production. Thus, keratinase enzyme by degrading poultry wastes (feather) can be an alternative approach to chemical dehairing in leather industries, thus preventing environmental pollution through bioremediation.

[Clinical and radiographic rationale for endodontic treatment of permanent teeth with periapical destruction]

In the course of the present study four endodontic treatment schemes were tested and the most effective scheme was determined through the use of calcium hydroxide-based paste being applied three times at an interval of 7-14 days with the subsequent long-term temporary obturation using calcium hydroxide with iodoform, ultrasonic activation of sodium hypochlorite in the root canal, hydrodynamic irrigation and a diode laser. During the entire treatment period, the most effective scheme has revealed a reduction in defect size by 2,57±0,17 (p>0,0001) as well as a 1,84 degree (p>0,0001) decrease in PAI score. Based on optical density data, it was concluded that the application of calcium hydroxide with iodoform in the treatment scheme leads to an 2,2-4,2% improvement in bone tissue regeneration in the periapical zone. The greatest and complete inhibition of microorganisms was determined in patients of the first and third experimental groups in which a diode laser was used. The use of a diode laser in endodontic dental treatment with periapical destruction, enhances antibacterial activity and contributes to the complete inhibition of pathogenic microflora in the root canals.

Nanoarray Digital Polymerase Chain Reaction with High-Resolution Melt for Enabling Broad Bacteria Identification and Pheno-Molecular Antimicrobial Susceptibility Test

Toward combating infectious diseases caused by pathogenic bacteria, there remains an unmet need for diagnostic tools that can broadly identify the causative bacteria and determine their antimicrobial susceptibilities from complex and even polymicrobial samples in a timely manner. To address this need, a microfluidic and machine-learning-based platform that performs broad bacteria identification (ID) and rapid yet reliable antimicrobial susceptibility testing (AST) is developed. Specifically, this platform builds on "pheno-molecular AST", a strategy that transforms nucleic acid amplification tests (NAATs) into phenotypic AST through quantitative detection of bacterial genomic replication, and utilizes digital polymerase chain reaction (PCR) and digital high-resolution melt (HRM) to quantify and identify bacterial DNA molecules. Bacterial species are identified using integrated experiment-machine learning algorithm via HRM profiles. Digital DNA quantification allows for rapid growth measurement that reflects susceptibility profiles of each bacterial species within only 30 min of antibiotic exposure. As a demonstration, multiple bacterial species and their susceptibility profiles in a spiked-in polymicrobial urine specimen were correctly identified with a total turnaround time of ∼4 h. With further development and clinical validation, this platform holds the potential for improving clinical diagnostics and enabling targeted antibiotic treatments.

Advances in Chemical and Biological Methods to Identify Microorganisms-From Past to Present

Fast detection and identification of microorganisms is a challenging and significant feature from industry to medicine. Standard approaches are known to be very time-consuming and labor-intensive (e.g., culture media and biochemical tests). Conversely, screening techniques demand a quick and low-cost grouping of bacterial/fungal isolates and current analysis call for broad reports of microorganisms, involving the application of molecular techniques (e.g., 16S ribosomal RNA gene sequencing based on polymerase chain reaction). The goal of this review is to present the past and the present methods of detection and identification of microorganisms, and to discuss their advantages and their limitations.

Efficacy of virginiamycin for the control of periodontal disease in calves

ABSTRACT: Periodontal diseases are multifactorial infectious processes caused by complexes of microorganisms, with damage to health, production, and animal welfare. The aim of the present study was to evaluate the efficacy of virginiamycin in the prevention and control of two early forms of periodontal disease: gingivitis and necrotizing gingivitis. Ten weaned calves, aged four to six months, were permanently kept in a single lot under the same rotational grazing regime in a newly reformed area of Panicum maximum. Five of the calves were orally administered 340mg of virginiamycin (Virginiamycin Group) daily for a period of 18 weeks, while the remaining five calves (Control Group) remained under the same food management but did not receive virginiamycin. During this period, animals underwent 18 weekly evaluations regarding periodontal health, with monitoring and recording of clinical parameters of the eight deciduous incisor teeth on the labial and lingual faces. At approximately two-week intervals, nine collections of subgingival sulcus material from five sites of the four right incisor teeth of each animal were performed and subjected to microbiological evaluation using polymerase chain reaction with primers of 25 microorganisms considered potentially pathogenic. After 1440 periodontal clinical evaluations of incisor teeth of the 10 calves, a total of 395 episodes of gingivitis were recorded, of which 267 occurred in the Control Group and 128 in the Virginiamycin Group. Similarly, 89 episodes of necrotizing gingivitis were recorded; 58 in the Control Group and 31 in the Virginiamycin Group. Comparison of between-group means found significant differences for teeth with gingivitis and necrotizing gingivitis (t test; p<0.05). The total number of teeth with gingivitis (p<0.01) and necrotizing gingivitis (p<0.01) in Control Group was significantly higher than that of gingivitis (p<0.01) and necrotizing gingivitis (p<0.05) in the Virginiamycin Group. There was a positive correlation between total occurrence of gingivitis and necrotizing gingivitis in the Virginiamycin Group by Pearson’s test. Virginiamycin had a protective effect on treated animals compared with the Control Group (OR = 0.36: CI (95%) = 0.27-0.43). In the Control Group, Actinomyces israelli (4.74%), domain Archaea (1.58%), Eikenella corrodens (1.05%), Fusobacterium nucleatum (27.37%), class Mollicutes (5.26%); Porphyromonas endodontalis(5.26%); Porphyromonas gulae(0.53%), Prevotella buccae (6.32%), Prevotella loescheii (3.68%), Prevotella nigrescens (8.42%), Prevotella oralis (1.58%), Tannerella forsythia (0.53%), and Treponema denticola (4.21%) were detected at healthy sites, and gingivitis or necrotizing gingivitis samples. In the Virginiamycin Group, A. israelli (3.41%), domain Archaea (0.98%), F. nucleatum (9.27%), class Mollicutes(4.39%), P. endodontalis (4.39%), P. gulae (0.49%), P. buccae (8.29%), P. loescheii (6.83%), P. nigrescens (15.61%), P. oralis (1.46%), Selenomonas sputigena (0.49%), T. forsythia (0.49%), and T. denticola (2.44%) were detected. In conclusion, virginiamycin administered at a dosage of 340mg/animal/day significantly reduced the occurrence of gingivitis and necrotizing gingivitis in cattle maintained on reformed pastures, and was revealed to have action against periodontal bacterial microbiota considered to be potentially pathogenic.

Dental caries are positively associated with periodontal disease severity

OBJECTIVES

To examine associations between periodontal disease severity and clinical and microbiological measures of caries in adults.

MATERIALS AND METHODS

A cross-sectional study of 94 healthy adults ((mean ± SD) 55.4 ± 13.0 years) was conducted. Data were collected by means of questionnaire and a clinical examination that included the Decayed, Missing, Filled teeth Surfaces (DMFS) index, probing depth (PD), clinical attachment level (CAL), and gingival bleeding and plaque scores. Supra- and subgingival plaque samples were collected to assess the presence of Streptococcus mutans and six periodontal pathogens. Participants were subsequently categorized using Center for Disease Control and Prevention/American Academy of Periodontology (CDC-AAP) definitions and tertiles of percentage of sites with CAL ≥ 3mm.

RESULTS

Significant positive associations were found between the periodontal disease severity (CDC-AAP) and the DMFS (aOR = 1.03; 95% CI 1.01-1.05) and DS indices (aOR = 1.18; 95% CI 1.05-1.32) as well as between the tertiles of percentage of sites with CAL ≥ 3 mm and DMFS (aOR = 1.03; 95% CI 1.00-1.05) and DS indices (aOR = 1.12; 95% CI 1.00-1.25). A significant positive association was also found between oral levels of F. nucleatum and S. mutans (aOR = 6.03; 95% CI 1.55-23.45).

CONCLUSIONS

A small but positive association was found between clinical measures of caries and periodontal disease severity. Further research is warranted to examine the association between these two common oral diseases.

CLINICAL RELEVANCE

Periodontal diseases and caries are the two most common oral diseases. There was a positive association between clinical and microbiological markers of both diseases. Therefore, strategies in oral health education should involve both caries and periodontitis prevention.

Endodontic Microbiology and Pathobiology: Current State of Knowledge

Newer research tools and basic science knowledge base have allowed the exploration of endodontic diseases in the pulp and periapical tissues in novel ways. The use of next generation sequencing, bioinformatics analyses, genome-wide association studies, to name just a few of these innovations, has allowed the identification of hundreds of microorganisms and of host response factors. This review addresses recent advances in endodontic microbiology and the host response and discusses the potential for future innovations in this area.

Correlation between crestal alveolar bone loss with intracanal bacteria and apical lesion area in necrotic teeth

OBJECTIVE

This study aimed to analyze the correlation between crestal alveolar bone loss with the presence of some bacterial species in root canals and the apical lesion area of necrotic teeth.

DESIGN

Data from 20 patients with diagnosis of pulp necrosis and acute apical abscesses, without active periodontal diseases, were evaluated. Patients with history of antibiotic usage three months prior to the study, with exposed pulp cavity, and with probing depth >3 mm were not included. The root size, the distance between the bone crest to the tooth apex in the mesial and distal surfaces, and the apical lesion area were measured from standard periapical radiographies by a calibrated examiner. Root canal samples were collected using sterilized paper points. In multirooted teeth, the largest root canal was sampled. Culture, microbial isolation and identification by phenotypic methods were performed. Spearman correlation and exact Fischer test were calculated between higher/lower existing bone crests, according to the median and the presence of specific bacteria.

RESULTS

No statistically significant differences were found between occurrence of pathogenic bacteria, such as Porphyromonas gingivalis, Porphyromonas endodontalis, and Prevotella intermedia, and groups with higher/lower degree of bone loss (p > 0.05). A negative significant correlation was found between Parvimonas micra and periodontal bone loss (p = 0.02). Additionally, no statistically significant association was found between crestal bone loss and the apical lesion area.

CONCLUSIONS

It was concluded that, in patients without active periodontitis, the presence of pathogenic bacteria in the root canal was not correlated with periodontal bone loss.

Partial purification and characterization of serine protease produced through fermentation of organic municipal solid wastes by Serratia marcescens A3 and Pseudomonas putida A2

Proteolytic bacteria isolated from municipal solid wastes (MSW) were identified as Serratia marcescens A3 and Pseudomonas putida A2 based on 16S rDNA sequencing. Protease produced through fermentation of organic MSW by these bacteria under some optimized physicochemical parameters was partially purified and characterized. The estimated molecular mass of the partially purified protease from S. marcescens and P. putida was approximately 25 and 38 kDa, respectively. Protease from both sources showed low Km 0.3 and 0.5 mg ml-1 and high Vmax 333 and 500 µmole min-1 at 40 °C, and thermodynamics analysis suggested formation of ordered enzyme-substrate (E-S) complexes. The activation energy (Ea) and temperature quotient (Q10) of protease from S. marcescens and P. putida were 16.2 and 19.9 kJ/mol, and 1.4 and 1.3 at temperature range from 20 to 40 °C, respectively. Protease of the both bacterial isolates was serine and cysteine type. The protease retained approximately 97% of activity in the presence of sodium dodecyl sulphate. It was observed that the purified protease of S. marcescens could remove blood stains from white cotton cloth and degrade chicken flesh remarkably. Our study revealed that organic MSW can be used as raw materials for bacterial protease production and the protease produced by S. marcescens A3 might be potential for applications.

The oral microbiome-the relevant reservoir for acute pediatric appendicitis?

PURPOSE

The oral microbiome has been related to numerous extra oral diseases. Recent studies detected a high abundance of oral bacteria in inflamed appendices in pediatric patients. To elucidate the role of oral bacteria in acute pediatric appendicitis, we studied the oral and appendiceal microbiome of affected children compared to healthy controls.

METHODS

Between January and June 2015, 21 children undergoing appendectomy for acute appendicitis and 28 healthy controls were prospectively enrolled in the study. All individuals underwent thorough dental examination and laboratory for inflammatory parameters. Samples of inflamed appendices and the gingival sulcus were taken for 16S rDNA sequencing. RT-qPCR of Fusobacterium nucleatum, Peptostreptococcus stomatis, and Eikenella corrodens was performed and their viability was tested under acidic conditions to mimic gastric transfer.

RESULTS

In phlegmonous appendices, Bacteroidetes and Porphyromonas were discovered as dominant phylum and genus. In sulcus samples, Firmicutes and Streptococcus were detected predominantly. P. stomatis, E. corrodens, and F. nucleatum were identified in each group. Viable amounts of P. stomatis were increased in sulci of children with acute appendicitis compared to sulci of healthy controls. In inflamed appendices, viable amounts of E. corrodens and F. nucleatum were decreased compared to sulci of children with appendicitis. Postprandial viability could be demonstrated for all tested bacteria.

CONCLUSION

In children with acute appendicitis, we identified several oral bacterial pathogens. Based on postprandial viability of selected species, a viable migration from the oral cavity through the stomach to the appendix seems possible. Thus, the oral cavity could be a relevant reservoir for acute appendicitis.