Subgingival microbiota of Brazilian subjects with untreated chronic periodontitis

Prevalence of Enterococcus species in adults with periodontal health or with periodontitis: a systematic review

The aim of this study was to evaluate the prevalence of Enterococcus species in the mouth of adults with periodontal health and periodontitis. A systematic search was made in databases in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The search for articles was conducted in Medline/PubMed, Latin American and Caribbean Health Sciences Literature Database (LILACS), Cochrane Library, Scopus, Embase, Web of Science databases and in the System of Information on Grey Literature in Europe (SINGLE) and included articles published in English up to April 25th, 2021. Observational studies in humans with and without periodontitis were evaluated to identify the prevalence of Enterococcus species. Articles that met the inclusion criteria were analyzed and classified to determine the quality rating in good, fair, and poor. A new detailed checklist for quality assessment was developed based on the information required for applicable data extraction in reviews. The study design, sample size, demographic data, periodontal clinical parameters, microbial analysis method, biological sample, prevalence of Enterococcus spp., and correlations with periodontal clinical parameters were assessed. After screening and full-text reading, 8 articles met the inclusion criteria. All selected studies showed a significantly higher prevalence of Enterococcus spp. in patients with periodontitis compared with periodontally healthy patients. Thus, the present systematic review suggests that the prevalence of Enterococcus faecalis in the mouth of periodontitis individuals is higher than that of periodontally healthy individuals.

Newly identified pathogens in periodontitis: evidence from an association and an elimination study

We assessed the level of evidence for the presence of new periodontal pathogens by (i) comparing the occurrence of non-classical periodontal taxa between healthy vs. periodontitis patients (Association study); (ii) assessing the modifications in the prevalence and levels of these species after treatments (Elimination study). In the Association study, we compared the prevalence and levels of 39 novel bacterial species between periodontally healthy and periodontitis patients. In the Elimination study, we analyzed samples from periodontitis patients assigned to receive scaling and root planing alone or with metronidazole+ amoxicillin TID/ 14 days. Levels of 79 bacterial species (39 novel and 40 classic) were assessed at baseline, 3 and 12 months post-therapy. All samples were analyzed using Checkerboard DNA-DNA hybridization. Out of the 39 novel species evaluated, eight were categorized as having strong and four as having moderate association with periodontitis. Our findings suggest strong evidence supporting Lancefieldella rimae, Cronobacter sakazakii, Pluralibacter gergoviae, Enterococcus faecalis, Eubacterium limosum, Filifactor alocis, Haemophilus influenzae, and Staphylococcus warneri, and moderate evidence supporting Escherichia coli, Fusobacterium necrophorum, Spiroplasma ixodetis, and Staphylococcus aureus as periodontal pathogens. These findings contribute to a better understanding of the etiology of periodontitis and may guide future diagnostic and interventional studies.

In Vivo Effect of a Nisin–Biogel on the Antimicrobial and Virulence Signatures of Canine Oral Enterococci

Periodontal disease is a relevant oral disease in dogs and nisin–biogel has been previously proposed to be used in its control. Enterococci, as inhabitants of the oral cavity with a high genetic versatility, are a reliable bacterial model for antimicrobial studies. Our goal was to evaluate the in vivo influence of the long-term dental application of the nisin–biogel on the virulence and antimicrobial signatures of canine oral enterococci. Twenty dogs were randomly allocated to one of two groups (treatment group—TG with nisin–biogel dental application, or control group—CG without treatment) and submitted to dental plaque sampling at day 0 and after 90 days (T90). Samples were processed for Enterococcus spp. isolation, quantification, identification, molecular typing and antimicrobial and virulence characterization. From a total of 140 enterococci, molecular typing allowed us to obtain 70 representative isolates, mostly identified as E. faecalis and E. faecium. No significant differences (p > 0.05) were observed in the virulence index of the isolates obtained from samples collected from the TG and CG at T90. At T90, a statistically significant difference (p = 0.0008) was observed in the antimicrobial resistance index between the isolates from the TC and CG. Oral enterococci were revealed to be reservoirs of high resistant and virulent phenotypes.

Oral biofilm dysbiosis during experimental periodontitis

OBJECTIVES

We have previously characterized the main osteoimmunological events that occur during ligature periodontitis. This study aims to determine the polymicrobial community shifts that occur during disease development.

METHODS

Periodontitis was induced in C57BL/6 mice using the ligature-induced periodontitis model. Healthy oral mucosa swabs and ligatures were collected every 3 days from 0 to 18 days post-ligature placement. Biofilm samples were evaluated by 16SrRNA gene sequencing (Illumina MiSeq) and QIIME. Time-course changes were determined by relative abundance, diversity, and rank analyses (PERMANOVA, Bonferroni-adjusted).

RESULTS

Microbial differences between health and periodontal inflammation were observed at all phylogenic levels. An evident microbial community shift occurred in 25 genera during the advancement of "gingivitis" (3-6 days) to periodontitis (9-18 days). From day 0 to 18, dramatic changes were identified in Streptococcus levels, with an overall decrease (54.04%-0.02%) as well an overall increase of Enterococcus and Lactobacillus (23.7%-73.1% and 10.1%-70.2%, respectively). Alpha-diversity decreased to its lowest at 3 days, followed by an increase in diversity as disease advancement. Beta-diversity increased after ligature placement, indicating that bone loss develops in response to a greater microbial variability (p = 0.001). Levels of facultative and strict anaerobic bacteria augmented over the course of disease progression, with a total of eight species significantly different during the 18-day period.

CONCLUSION

The data supports that murine gingival inflammation and alveolar bone loss develop in response to microbiome shifts. Bacterial diversity increased during progression to bone loss. These findings further support the utilization of the periodontitis ligature model for microbial shift analysis under different experimental conditions.

The subgingival cultivable bacteria of Albanian subjects with different periodontal status compared to a similar population of Spanish subjects: a case control study

Background

The objective was to qualitatively and quantitatively describe the subgingival cultivable bacteria in Albanian subjects and to compare it with a similar Spanish population.

Materials and methods

Consecutive patients, diagnosed as periodontitis in stages I–II or III–IV, and as periodontally healthy or with gingivitis, were studied clinically and microbiologically by means of microbiological culture, including total anaerobic counts, proportions, and frequency of detection of target species. Outcome variables were analysed by Mann–Whitney, Kruskal–Wallis, ANOVA, ANCOVA and Chi-square tests.

Results

In this cross-sectional study, 83 (Albania) and 90 (Spain) subjects were included. No statistically significant differences were observed between test and control populations regarding demographic variables or smoking habit. Significantly higher total anaerobic counts in the Albanian population (p = 0.022) were observed, especially in the periodontal health/gingivitis group (p = 0.001). In the test population, the proportions of the cultivable bacteria of Fusobacterium nucleatum were significantly lower in both the healthy/gingivitis (p = 0.022) and stages I–II periodontitis (p = 0.034) groups.

Conclusions

The subgingival cultivable bacteria in both periodontitis and non-periodontitis subjects from Albania showed significantly higher total anaerobic counts and lower proportions of the cultivable bacteria of F. nucleatum than a similar population of subjects from Spain.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-022-02121-5.

Oral Dysbiosis in Severe Forms of Periodontitis Is Associated With Gut Dysbiosis and Correlated With Salivary Inflammatory Mediators: A Preliminary Study

Inflammation is a driven force in modulating microbial communities, but little is known about the interplay between colonizing microorganisms and the immune response in periodontitis. Since local and systemic inflammation may play a whole role in disease, we aimed to evaluate the oral and fecal microbiome of patients with periodontitis and to correlate the oral microbiome data with levels of inflammatory mediator in saliva. Methods: Nine patients with periodontitis (P) in Stage 3/Grade B and nine age-matched non-affected controls (H) were evaluated. Microbial communities of oral biofilms (the supra and subgingival from affected and non-affected sites) and feces were determined by sequencing analysis of the 16SrRNA V3-V4 region. Salivary levels of 40 chemokines and cytokines were correlated with oral microbiome data. Results: Supragingival microbial communities of P differed from H (Pielou's evenness index, and Beta diversity, and weighted UniFrac), since relative abundance (RA) of Defluviitaleaceae, Desulfobulbaceae, Mycoplasmataceae, Peptostreococcales-Tissierellales, and Campylobacteraceae was higher in P, whereas Muribaculaceae and Streptococcaceae were more abundant in H. Subgingival non-affected sites of P did not differ from H, except for a lower abundance of Gemellaceae. The microbiome of affected periodontitis sites (PD ≥ 4 mm) clustered apart from the subgingival sites of H. Oral pathobionts was more abundant in sub and supragingival biofilms of P than H. Fecal samples of P were enriched with Acidaminococcus, Clostridium, Lactobacillus, Bifidobacterium, Megasphaera, and Romboutsia when compared to H. The salivary levels of interleukin 6 (IL-6) and inflammatory chemokines were positively correlated with the RA of several recognized and putative pathobionts, whereas the RA of beneficial species, such as Rothia aeria and Haemophilus parainfluenzae was negatively correlated with the levels of Chemokine C-C motif Ligand 2 (CCL2), which is considered protective. Dysbiosis in patients with periodontitis was not restricted to periodontal pockets but was also seen in the supragingival and subgingival non-affected sites and feces. Subgingival dysbiosis revealed microbial signatures characteristic of different immune profiles, suggesting a role for candidate pathogens and beneficial organisms in the inflammatory process of periodontitis.

Wear and fracture of curettes due to sharpening and scaling processes

OBJECTIVES

To examine the wear occurring in a group of new Gracey curettes due to the sharpening and scaling processes and record the number of service cycles before breakage.

METHODS

This study included 592 working ends of Gracey curettes that were subjected to cycles of sharpening and scaling. Three-dimensional measurements of the blades and the status of the working ends were recorded before and after each process.

RESULTS

With an increase in the number of usage cycles, the three-dimensional measurements of the blades decreased. During this study, 184 working ends were broken, of which 38.59% were of #11/12 Gracey curettes, and only 8.15% were of #7/8 Gracey curettes. The average number of cycles required for the fracture of Gracey curettes was 14.34. Cox regression analyses showed that the factors influencing the survival cycles were the tip width before usage and the type of Gracey curette. Moreover, the sharpening process was responsible for approximately half of the total instrument wear. Among the four types of Gracey curettes, the #11/12 Gracey curettes showed the greatest amount of sharpening wear, accounting for > 50% of the total wear.

CONCLUSIONS

The service life of Gracey curettes varies according to their types; the #11/12 Gracey curettes are more susceptible to breakage, while #7/8 Gracey curettes tend to have a long service life. Furthermore, the sharpening process was responsible for a considerable amount of curette wear.

Dental Plaque Microbial Resistomes of Periodontal Health and Disease and Their Changes after Scaling and Root Planing Therapy

The human oral microbial community has been considered a reservoir of antibiotic resistance. Currently, the effects of periodontitis and the scaling and root planing (SRP) treatment on the performance of antibiotic-resistant genes (ARGs) and metal-resistant genes (MRGs) in the dental plaque microbiota are not well characterized. To explore this issue, we selected 48 healthy-state (HS), 40 periodontitis-state (PS; before treatment), and 24 resolved-state (RS; after SRP treatment) metagenomic data of dental plaque samples from the Sequence Read Archive (SRA) database. NetShift analysis identified Fretibacterium fastidiosum, Tannerella forsythia, and Campylobacter rectus as key drivers during dental plaque microbiota alteration in the progression of periodontitis. Periodontitis and SRP treatment resulted in an increase in the number of ARGs and MRGs in dental plaque and significantly altered the composition of ARG and MRG profiles. Bacitracin, beta-lactam, macrolide-lincosamide-streptogramin (MLS), tetracycline, and multidrug resistance genes were the main classes of ARGs with high relative abundance, whereas multimetal, iron, chromium, and copper resistance genes were the primary types of MRGs in dental plaque microbiota. The cooccurrence of ARGs, MRGs, and mobile genetic elements (MGEs) indicated that a coselection phenomenon exists in the resistomes of dental plaque microbiota. Overall, our data provide new insights into the standing of the distribution of ARGs and MRGs in oral microbiota of periodontitis patients, and it was possible to contribute to the understanding of the complicated correlations among microorganisms, resistomes, and MGEs. IMPORTANCE The emergence and development of resistance to antibiotics in periodontal pathogens have affected the success rate of treatment for periodontitis. The development of new antibacterial strategies is urgently needed to help control and treat periodontal disease, and dental plaque microbiome studies offer a promising new angle of attack. In this study, we investigated the dental plaque microbiota and resistomes in periodontal health and disease states and their changes after SRP therapy. This is the first analysis of the profile of the microbial community and antibiotic and metal resistance genes in dental plaque by the metagenomic approach, to the best of our knowledge. Monitoring the profile of these resistomes has huge potential to provide reference levels for proper antibiotics use and the development of new antimicrobial strategies in periodontitis therapy and thereby improve actual efficacy of the treatment regimens.

The effectiveness of using the perioscope as an adjunct to non-surgical periodontal therapy: Clinical and radiographic results

BACKGROUND

It is well known that following root surface debridement (RSD) residual deposits remain. Periodontal endoscopy has provided a method of directly visualizing root surfaces during periodontal debridement in an intact pocket without the need for surgical incision. The aim of this study was to determine if periodontal debridement using endoscopic visualization was more effective in improving clinical and radiographic parameters as compared to RSD.

METHODS

Thirty-eight subjects were randomized into RSD with perioscope (n = 19) or RSD only (n = 19) groups. A full-mouth evaluation included probing pocket depths (PPDs), clinical attachment levels (CAL), bleeding on probing (BOP) and plaque scores (PI) recorded at baseline, 3 and 12 months and compared among groups. Radiographs were taken at sites with deepest pockets at baseline and 12-month and the change in radiographic bone levels (RBL) compared. An independent samples T-test was used to assess statistical significance.

RESULTS

Both groups had significant improvements in clinical outcomes. The test (T) group had a significantly lower percentage of PPDs 7 to 9 mm at three (0.72 ± 1.2%) and 12 months (0.5 ± 1.0%) as compared with the control (C) group (2.25 ± 2.9%; 1.84 ± 2.3%). At 12 months, the test group recorded a significantly lower mean PPD (T: 2.70 + 0.2 mm; C: 2.98 ± 0.4 mm), BOP% (T: 4.3 ± 3.2%; C: 11.95 ± 7.1%), PI% (T: 25.61 ± 3.9%; C: 30.11 ± 6.3%) and less change in gingival recession (T: -0.13 ± 0.2 mm; C: -0.50 ± 0.6 mm) (P < 0.05). More radiographic bone gain was observed in the test group (0.69 ± 0.3 mm) as compared with the control group (0.49 ± 0.2 mm). This was also observed around multi-rooted teeth (T: 0.83 ± 0.45 mm; C: 0.46 ± 0.36 mm).

CONCLUSION

The adjunctive use of the perioscope provided a slight benefit to the outcomes of non-surgical therapy particularly at deeper probing depths.

Recent Development of Active Ingredients in Mouthwashes and Toothpastes for Periodontal Diseases

Periodontal diseases like gingivitis and periodontitis are primarily caused by dental plaque. Several antiplaque and anti-microbial agents have been successfully incorporated into toothpastes and mouthwashes to control plaque biofilms and to prevent and treat gingivitis and periodontitis. The aim of this article was to review recent developments in the antiplaque, anti-gingivitis, and anti-periodontitis properties of some common compounds in toothpastes and mouthwashes by evaluating basic and clinical studies, especially the ones published in the past five years. The common active ingredients in toothpastes and mouthwashes included in this review are chlorhexidine, cetylpyridinium chloride, sodium fluoride, stannous fluoride, stannous chloride, zinc oxide, zinc chloride, and two herbs—licorice and curcumin. We believe this comprehensive review will provide useful up-to-date information for dental care professionals and the general public regarding the major oral care products on the market that are in daily use.

Antimicrobial susceptibility and virulence of Enterococcus spp. isolated from periodontitis-associated subgingival biofilm

BACKGROUND

This study evaluated the prevalence, virulence and antimicrobial susceptibility of enterococci isolated from the subgingival microbiota of patients with different periodontal status.

METHODS

Subgingival biofilm was obtained from individuals with periodontal health (PH) (n = 139), gingivitis (n = 103), and periodontitis (n = 305) and cultivated on selective media. Isolated strains were identified by mass spectrometry. Antimicrobial sensitivity was determined by disk diffusion, virulence genes by polymerase chain reaction, and the subgingival microbiota by checkerboard. Differences among groups were assessed by Kruskal-Wallis, Mann-Whitney, and Chi-square tests.

RESULTS

Enterococcus spp. were isolated from 7.4% of all samples; 53.7% were Enterococcus faecalis. They were more prevalent in periodontitis (9.8%) and gingivitis (7.8%) than PH (2.2%; P <0.05), but no differences among stages of disease severity were observed. High rates of low susceptibility/resistance (>64%) to at least one antimicrobial were observed. Predominant virulence factors included ace (64.3%), asa (39.3%), and esp (35.7%). Fusobacterium nucleatum was prevalent in the subgingival microbiota of enterococci+ individuals, whereas Dialister pneumosintes was found in low frequency in patients with bopD+ enterococci. Oral streptococci were prevalent (>70%) in patients carrying enterococci susceptible to doxycycline (P <0.05), usually bopD- and esp- (P <0.01).

CONCLUSIONS

E. faecalis is increased in periodontitis-associated biofilm. Oral enterococci carry virulence genes and express resistance to some antibiotics commonly used in dentistry, such as ciprofloxacin and erythromycin. Specific subgingival taxa are associated with oral enterococci, suggesting they may interact with species of the dysbiotic periodontitis biofilm, constituting a potential source of factors to tissue destruction, antibiotic resistance dissemination, and poor response to periodontal therapy.

Prediction of Chronic Periodontitis Severity Using Machine Learning Models Based On Salivary Bacterial Copy Number

Periodontitis is a widespread chronic inflammatory disease caused by interactions between periodontal bacteria and homeostasis in the host. We aimed to investigate the performance and reliability of machine learning models in predicting the severity of chronic periodontitis. Mouthwash samples from 692 subjects (144 healthy controls and 548 generalized chronic periodontitis patients) were collected, the genomic DNA was isolated, and the copy numbers of nine pathogens were measured using multiplex qPCR. The nine pathogens are as follows: Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf), Treponema denticola (Td), Prevotella intermedia (Pi), Fusobacterium nucleatum (Fn), Campylobacter rectus (Cr), Aggregatibacter actinomycetemcomitans (Aa), Peptostreptococcus anaerobius (Pa), and Eikenella corrodens (Ec). By adding the species one by one in order of high accuracy to find the optimal combination of input features, we developed an algorithm that predicts the severity of periodontitis using four machine learning techniques. The accuracy was the highest when the models classified “healthy” and “moderate or severe” periodontitis (H vs. M-S, average accuracy of four models: 0.93, AUC = 0.96, sensitivity of 0.96, specificity of 0.81, and diagnostic odds ratio = 112.75). One or two red complex pathogens were used in three models to distinguish slight chronic periodontitis patients from healthy controls (average accuracy of 0.78, AUC = 0.82, sensitivity of 0.71, and specificity of 0.84, diagnostic odds ratio = 12.85). Although the overall accuracy was slightly reduced, the models showed reliability in predicting the severity of chronic periodontitis from 45 newly obtained samples. Our results suggest that a well-designed combination of salivary bacteria can be used as a biomarker for classifying between a periodontally healthy group and a chronic periodontitis group.

Did Omics change periodontal therapy?

The starting point for defining effective treatment protocols is a clear understanding of the etiology and pathogenesis of a condition. In periodontal diseases, this understanding has been hindered by a number of factors, such as the difficulty in differentiating primary pathogens from nonpathogens in complex biofilm structures. The introduction of DNA sequencing technologies, including taxonomic and functional analyses, has allowed the oral microbiome to be investigated in much greater breadth and depth. This article aims to compile the results of studies, using next-generation sequencing techniques to evaluate the periodontal microbiome, in an attempt to determine how far the knowledge provided by these studies has brought us in terms of influencing the way we treat periodontitis. The taxonomic data provided, to date, by published association and elimination studies using next-generation sequencing confirm previous knowledge on the role of classic periodontal pathogens in the pathobiology of disease and include new species/genera. Conversely, species and genera already considered as host-compatible and others less explored were associated with periodontal health as their levels were elevated in healthy individuals and increased after therapy. Functional and transcriptomic analyses also demonstrated that periodontal biofilms are taxonomically diverse, functionally congruent, and highly cooperative. Very few interventional studies to date have examined the effects of treatment on the periodontal microbiome, and such studies are heterogeneous in terms of design, sample size, sampling method, treatment provided, and duration of follow-up. Hence, it is still difficult to draw meaningful conclusions from them. Thus, although OMICS knowledge has not yet changed the way we treat patients in daily practice, the information provided by these studies opens new avenues for future research in this field. As new pathogens and beneficial species become identified, future randomized clinical trials could monitor these species/genera more comprehensively. In addition, the metatranscriptomic data, although still embryonic, suggest that the interplay between the host and the oral microbiome may be our best opportunity to implement personalized periodontal treatments. Therapeutic schemes targeting particular bacterial protein products in subjects with specific genetic profiles, for example, may be the futuristic view of enhanced periodontal therapy.

The effect of lipoxin A4 on E. coli LPS-induced osteoclastogenesis

Objectives

The objective of the present study was to investigate the effect of lipoxin-type A4 (LXA4) on bacterial-induced osteoclastogenesis.

Material and methods

Human periodontal ligament cells (PDLCs) in coculture with osteoclast precursors (RAW264.7 cells) were exposed to bacterial stimulation with lipopolysaccharide (LPS) to induce inflammation. After 24 h, cells were treated to 100 ng/ml of LXA4 and 50 ng/ml of forymul peptide receptor 2 (FPR2/ALX) receptor antagonist (Boc-2). After 5 days, osteoclastic resorptive activity was assessed on calcium phosphate (CaP) synthetic bone substitute. Additionally, osteoclastic differentiation was evaluated using tartrate-resistant acid phosphatase (TRAP) staining, TRAP enzymatic activity assay, and on the expression of osteoclast-specific genes.

Results

We found that stimulation of in the osteoclasts with LPS-stimulated PDLCs induced a significant increase in tartrate-resistant acid phosphatase (TRAP) positive cells, higher resorptive activity, and enhanced expression of specific genes. Meanwhile, LXA4-treatment exhibited strong anti-inflammatory activity, and was able to reverse these inflammatory effects.

Conclusions

We conclude that (1) PDLCs are a potential target for treating bacterial-induced bone resorption in patients with periodontal disease, and (2) LXA4 is a suitable candidate for such therapy.

Clinical relevance

The results prove that lipoxins have a protective role in bacterial-induced periodontal inflammation and alveolar bone resorption, which can be translated into a clinical beneficial alterative treatment.

Early and accurate detection of bacterial isolates from dental plaque in subjects with primary, mixed, and permanent dentition by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry technique

Background:

Bacterial colonization of dentition in different age groups can impact prognosis in different dental diseases. Latest diagnostic technique such as matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF) is increasingly being used for accurate identification of bacteria. This study was undertaken to evaluate the MALDI-TOF MS technique to identify bacterial pathogens from dental plaques in subjects with primary, mixed, and permanent dentition.

Materials and Methods:

The study included 150 subjects of different age groups and were divided into three groups - Group A: Subjects with primary dentition (n = 50), Group B: Subjects with mixed dentition (n = 50), and Group C: Subjects with permanent dentition (n = 50). Subgingival dental plaque samples were collected from buccal and lingual surfaces of premolar and molar teeth. Clinical parameters such as gingival index were recorded. Samples were cultured in routine aerobic and anaerobic medium. Bacterial growths were assessed by semiquantitative methods. Bacterial isolates were confirmed by MALDI-TOF MS technique.

Results:

MALDI-TOF MS detected all the culture-grown bacteria. In primary dentition group, purple and yellow complex bacteria predominated. Streptococcus spp. was the predominant bacteria (51%) followed by Escherichia coli (19%) and Veillonella spp. (19%). In mixed dentition and permanent group also, Streptococcus spp. was predominant (46%) followed by Veillonella spp. (24%) and E. coli(19%). However, in both groups, orange complex bacteria (bridge complex) such as Prevotella nigrescens and red complex bacteria (Porphyromonas gingivalis, 3%) were seen. For majority of bacteria, the load increased with age.

Conclusions:

The bacterial isolates showed a distinct age-specific colonization. The use of advanced technique such as MALDI-TOF MS is helpful in the detection of periodontal pathogens, and the effective oral health programs can be implemented to minimize the risk of periodontal diseases.

Biology of Oral Streptococci

Bacteria belonging to the genus Streptococcus are the first inhabitants of the oral cavity, which can be acquired right after birth and thus play an important role in the assembly of the oral microbiota. In this article, we discuss the different oral environments inhabited by streptococci and the species that occupy each niche. Special attention is given to the taxonomy of Streptococcus, because this genus is now divided into eight distinct groups, and oral species are found in six of them. Oral streptococci produce an arsenal of adhesive molecules that allow them to efficiently colonize different tissues in the mouth. Also, they have a remarkable ability to metabolize carbohydrates via fermentation, thereby generating acids as byproducts. Excessive acidification of the oral environment by aciduric species such as Streptococcus mutans is directly associated with the development of dental caries. However, less acid-tolerant species such as Streptococcus salivarius and Streptococcus gordonii produce large amounts of alkali, displaying an important role in the acid-base physiology of the oral cavity. Another important characteristic of certain oral streptococci is their ability to generate hydrogen peroxide that can inhibit the growth of S. mutans. Thus, oral streptococci can also be beneficial to the host by producing molecules that are inhibitory to pathogenic species. Lastly, commensal and pathogenic streptococci residing in the oral cavity can eventually gain access to the bloodstream and cause systemic infections such as infective endocarditis.

Antimicrobial Activity of Piper marginatum Jacq and Ilex guayusa Loes on Microorganisms Associated with Periodontal Disease

Background

Chronic periodontitis is a multifactorial infectious disease, where multiple bacteria, such as Porphyromonas gingivalis, Prevotella intermedia, and Fusobacterium nucleatum are implicated. The main purpose of researching natural products is to find substances or compounds with antimicrobial activity.

Aim

The objective of this work was to determine antimicrobial activity from extracts and obtained fractions from Piper marginatum Jacq and Ilex guayusa Loes on P. gingivalis ATCC 33277, F. nucleatum ATCC 25586, and P. intermedia ATCC 25611.

Methods

Total ethanol extracts were obtained from both plants. Fractions were obtained from total ethanol extracts with amberlite as a stationary phase employing hexane, acetone, and ethanol-water as solvents. Qualitative and quantitative phytochemical characterization was performed on total ethanol extracts from both plants. Antimicrobial activity from total ethanol extracts and fractions from both plants were evaluated on P. gingivalis ATCC 33277, F. nucleatum ATCC 25586, and P. intermedia ATCC by the well diffusion method with Wilkins-Chalgren agar.

Results

Piper marginatum Jacq total ethanol extract presented antimicrobial activity against all three bacteria, whereas Ilex guayusa Loes was only efficient against P. gingivalis ATCC 33277 and P. intermedia ATCC 25611, with inhibition halos from 9.3 to 30 mm. Ilex guayusa Loes obtained fractions presented antimicrobial activity against all three microorganisms evaluated, with inhibition halos ranging from 9.7 to 18.7 mm. In regards to Piper marginatum Jacq fractions, inhibition halos were between 8.3 and 19 mm, against all three microorganisms evaluated; only hexane fraction did not present antimicrobial activity against F. nucleatum ATCC 25586.

Conclusion

Piper marginatum Jacq and Ilex guayusa Loes total ethanol extracts and fractions presented outstanding antimicrobial activity against P. gingivalis ATCC 33277, P. intermedia ATCC 25611, and F. nucleatum ATCC 25586.

The Effects of Antimicrobial Peptide Nal-P-113 on Inhibiting Periodontal Pathogens and Improving Periodontal Status

Periodontal disease consists of chronic gingival inflammation characterized by both degradation of the periodontal connective tissue and alveolar bone loss. Drug therapy is used as an auxiliary treatment method in severe chronic periodontitis, aggressive periodontitis, and periodontitis-associated systemic disease. Nal-P-113, a modified antimicrobial peptide, specifically replaces the histidine residues of P-113 with the bulky amino acid β-naphthylalanine, and our previous studies have verified that this novel peptide is not toxic to the human body within a certain concentration range. The objective of the present study was to evaluate the effect of Nal-P-113 on periodontal pathogens and periodontal status in clinical studies. In a split-mouth clinical trial, the pocket depth and bleeding index values tended to decrease in the experimental group compared with those in the control group. SEM results verified that Nal-P-113 restrained the maturation of plaque. Based on real-time polymerase chain reaction, the levels of Fusobacterium nucleatum, Streptococcus gordonii, Treponema denticola, and Porphyromonas gingivalis in subgingival plaque were decreased when the subjects were given Nal-P-113. Bacterial growth curve analysis and a biofilm susceptibility assay verified that Nal-P-113 at a concentration of 20 μg/mL restrained the growth of S. gordonii, F. nucleatum, and P. gingivalis and biofilm formation. Therefore, Nal-P-113 effectively reduces periodontal pathogens and ameliorates periodontal status.

Molecular-level evaluation of selected periodontal pathogens from subgingival regions in canines and humans with periodontal disease

Dogs commonly serve as a model for various human conditions, including periodontal diseases. The aim of this study was to identify the anaerobic bacteria that colonize the subgingival areas in dogs and humans by using rapid real-time polymerase chain reaction (RT-PCR)-based tests and to compare the results obtained in each species. Bacterial microflora evaluations, both quantitative and qualitative, were performed by applying ready-made tests on twelve dogs and twelve humans. Five samples were collected from each subject's deepest gingival pockets and joined to form a collective sample. The results of the study revealed interspecies similarities in the prevalences of Porphyromonas (P.) gingivalis, Treponema denticola, Tannerella forsythia, and Fusobacterium nucleatum. Red complex bacteria comprised the largest portion of the studied bacterial complexes in all study groups, with P. gingivalis being the most commonly isolated bacterium. The results show similarities in the prevalence of bacterial microflora in dogs and humans. Microbiological analysis of gingival pockets by using rapid real-time PCR-based tests in clinical practice, both veterinary and human, can facilitate the choice of appropriate pharmacological treatment and can provide a basis for subsequent verification of the treatment's effectiveness.

Subgingival prevalence rate of enteric rods in subjects with periodontal health and disease

BACKGROUND

The prevalence of enteric rods and their association with chronic periodontitis has gained prominence recently. Although the prevalence of these organisms from the subgingival plaque sample was reported in the literature, the carriage rate of these rods in our population is lacking. The present study was undertaken to know the carriage rate of enteric rods from our population in patients with periodontal health and disease.

MATERIALS AND METHODS

Eighty-four systemically healthy participants, inclusive of 46 males and 38 females, were selected for the study. The selected participants were subjected to a periodontal examination and were categorized into chronic periodontitis and healthy group. Subgingival plaque samples were taken from all the participants, plated onto McConkey agar plates, and incubated overnight at 37° C to check for the growth of organisms. The grown organisms were then cultured according to the standard procedures.

RESULTS

Prevalence of 71% and 83% of enteric rods in subjects with periodontal health and disease, respectively, was found in our study which was not statistically significant.

CONCLUSION

Although no significant differences exist in the prevalence of enteric rods between healthy and patients with chronic periodontitis, the prevalence rate of enteric rods in subgingival plaque samples is considerably high in our population.

The investigation of Helicobacter pylori in the dental biofilm and saliva samples of children with dyspeptic complaints

Background

The oral cavity can be an extra-gastric reservoir for Helicobacter pylori (H.pylori). This can play a role in the pathogenesis of halitosis, glossitis, recurrent aphthous stomatitis, and dental caries. The present study was conducted to detect the presence of H.pylori within the dental biofilm and in saliva samples collected from children suffering from dyspepsia and children without any gastrointestinal complaints. Associations with gastric infection, halitosis, and some oral parameters were also evaluated.

Methods

Seventy children (aged between 5–16) with dyspepsia were selected for the study group and control group composed of 30 healthy children without dyspepsia were also included in the study. After detailed oral and clinical examinations for oral parameters, saliva, and supragingival dental biofilm samples were collected for 16S rRNA and 23S rRNA genes detection by real-time polymerase chain reaction (RT-PCR). The presence of gastric H.pylori was evaluated in endoscopic biopsy specimens histopathologically. Halitosis was evaluated by benzoyl-DL-arginine-naphthylamid (BANA) test. Salivary S.mutans and Lactobacilli sp. counts were also carried out by commercial kits.

Results

H.pylori was histopathologically detected amongst 83% of the children with the dyspeptic condition. The detection rate of this bacteria in dental biofilm and saliva samples and halitosis were found relatively higher in the dyspeptic children rather than the control group (p < 0.01). Halitosis was not significantly different between dyspeptic children and those detected with H.pylori (p > 0.05). In the gastric H.pylori positive group with dyspepsia, DMFT/S and dmft/s numbers and plaque indices were found higher than the control group (p < 0.01). Only plaque indices of gastric H.pylori negative group with dyspepsia were found higher than the control group (p < 0.01). S.mutans and Lactobacilli sp. counts were not significantly different between gastric H.pylori positive and negative groups (p > 0.05). Comparing to those with negative for both genes, in children whose dental biofilm and saliva samples were positive for both 16S rRNA and 23S rRNA genes, significantly higher results for halitosis, and DMFS numbers and significantly lower results for dmfs numbers and pH values were found (p < 0.01).

Conclusions

Helicobacter pylori can occur in the oral cavity aside and independently from the stomach. However, the high number of bacteria in the oral cavities of children with gastric H.pylori, an association between the presence of H.pylori and halitosis, DMFS, and pH were found.

Electronic supplementary material

The online version of this article (doi:10.1186/s12903-017-0361-x) contains supplementary material, which is available to authorized users.

Systemic antibiotics in the treatment of periodontitis

Despite the fact that several clinical studies have shown additional benefits when certain systemic antibiotics are used as adjuncts to periodontal treatment, clear guidelines for the use of these agents in the clinical practice are not yet available. Basic questions concerning the use of systemic antibiotics to treat periodontitis remain unanswered, such as: which drug(s) should be used; which patients would most benefit from treatment; which are the most effective protocols (i.e. doses and durations); and in which phase of the mechanical therapy should the drug(s) be administered? Although not all of those questions have been directly addressed by controlled randomized clinical trials, recent concepts related to the ecology of periodontal diseases, as well as the major advances in laboratory and clinical research methods that have occurred in the past decade, have significantly broadened our knowledge in this field. This article endeavored to provide a 'state of the art' overview on the use of systemic antibiotics in the treatment of periodontitis, based on the most recent literature on the topic as well as on a compilation of data from studies conducted at the Center of Clinical Trials at Guarulhos University (São Paulo, Brazil) from 2002 to 2012.

Modulation of drug resistance and biofilm formation of Staphylococcus aureus isolated from the oral cavity of Tunisian children

Objectives

This study aims to investigate the antimicrobial and the anti-biofilm activities of Lactobacillus plantarum extract (LPE) against a panel of oral Staphylococcus aureus (n = 9) and S. aureus ATCC 25923. The in vitro ability of LPE to modulate bacterial resistance to tetracycline, benzalchonium chloride, and chlorhexidine were tested also.

Methods

The minimum inhibitory concentrations (MICs) and the minimal bactericidal concentrations of Lactobacillus plantarum extract, tetracycline, benzalchonium chloride and clohrhexidine were determined in absence and in presence of a sub-MIC doses of LPE (1/2 MIC). In addition, the LPE potential to inhibit biofilm formation was assessed by microtiter plate and atomic force microscopy assays. Statistical analysis was performed on SPSS v. 17.0 software using Friedman test and Wilcoxon signed ranks test. These tests were used to assess inter-group difference (p < 0.05).

Results

Our results revealed that LPE exhibited a significant antimicrobial and anti-biofilm activities against the tested strains. A synergistic effect of LPEs and drug susceptibility was observed with a 2–8-fold reduction.

Conclusion

LPE may be considered to have resistance-modifying activity. A more detailed investigation is necessary to determine the active compound responsible for therapeutic and disinfectant modulation.

Detection of Porphyromonas gingivalis and Treponema denticola in chronic and aggressive periodontitis patients: A comparative polymerase chain reaction study

BACKGROUND

The detection frequency of Porphyromonas gingivalis and Treponema denticola in chronic periodontitis (CP) and aggressive periodontitis (AgP) is not explored well in Indian population.

AIM

The study was undertaken to detect P. gingivalis and T. denticola in CP as well as in AgP patients using polymerase chain reaction (PCR), and to determine the relationship between the frequency of these two microorganisms and the severity of clinical periodontal parameters.

MATERIALS AND METHODS

Subgingival plaque samples were collected from ninety participants (thirty CP patients, thirty AgP patients, and thirty healthy participants) and the aforementioned two microorganisms were detected using PCR.

RESULTS

However, when CP and AgP were compared for the detection frequency of two microorganisms, no statistically significant difference was noted. A statistically significant increase in the number of bacteria-positive sites increased as the score of plaque index (PI), gingival index (GI), and clinical attachment level of CP and AgP patients increased. Coexistence of P. gingivalis and T. denticola was frequently observed in deep periodontal pockets.

CONCLUSIONS

Study findings suggest that P. gingivalis and T. denticola are significantly associated with the severity of periodontal tissue destruction. Statistically significant association exists between clinical periodontal parameters such as PI, GI, periodontal pocket depth (PPD), and clinical attachment loss and presence of both the microorganisms.

Antibiotic susceptibility of periodontal Streptococcus constellatus and Streptococcus intermedius clinical isolates

BACKGROUND

Streptococcus constellatus and Streptococcus intermedius in subgingival dental plaque biofilms may contribute to forms of periodontitis that resist treatment with conventional mechanical root debridement/surgical procedures and may additionally participate in some extraoral infections. Because systemic antibiotics are often used in these clinical situations, and little is known of the antibiotic susceptibility of subgingival isolates of these two bacterial species, this study determined the in vitro susceptibility to six antibiotics of fresh S. constellatus and S. intermedius clinical isolates from human periodontitis lesions.

METHODS

A total of 33 S. constellatus and 17 S. intermedius subgingival strains, each recovered from separate patients with severe chronic periodontitis (n = 50) before treatment, were subjected to antibiotic gradient strip susceptibility testing with amoxicillin, azithromycin, clindamycin, ciprofloxacin, and doxycycline on blood-supplemented Mueller-Hinton agar and to the inhibitory effects of metronidazole at 16 mg/L in an enriched Brucella blood agar dilution assay. Clinical and Laboratory Standards Institute and European Committee on Antimicrobial Susceptibility Testing interpretative standards were used to assess the results.

RESULTS

Clindamycin was the most active antibiotic against S. constellatus (minimum inhibitory concentration at 90% [MIC90] 0.25 mg/L), and amoxicillin was most active against S. intermedius (MIC90 0.125 mg/L). A total of 30% of the S. constellatus and S. intermedius clinical isolates were resistant in vitro to doxycycline, 98% were only intermediate in susceptibility to ciprofloxacin, and 90% were resistant to metronidazole at 16 mg/L.

CONCLUSION

Subgingival S. constellatus and S. intermedius exhibited variable antibiotic susceptibility profiles, potentially complicating empirical selection of periodontitis antibiotic therapy in patients who are species positive.

Periodontal-disease-associated biofilm: A reservoir for pathogens of medical importance

The ecological diversity of the periodontal microenvironment may provide suitable conditions for the colonization of species not usually considered members of the oral microbiota. In this investigation, we aimed to determine the prevalence and levels of pathogenic species of medical relevance in the microbiota of individuals with distinct periodontal clinical status. Subgingival biofilm was obtained from patients with periodontal health (H, n = 81), gingivitis (G, n = 55), generalized aggressive (AgP, n = 36) or chronic periodontitis (CP, n = 98), and analyzed for 39 microbial taxa using a checkerboard DNA-DNA hybridization technique. Microbial differences among groups, as well as associations between clinical and microbiological parameters were sought by non-parametric and univariate correlation tests. Neisseria spp., Peptostreptococus anaerobius, Candida albicans, enterobacteria, Pseudomonas aeruginosa, Eubacterium saphenum, Clostridium difficile and Olsenella uli were detected in high mean prevalence and counts in the subgingival microbiota of the study population. Species that were more related to periodontal inflammation and tissue destruction at the patient and site levels included enterobacteria, C. albicans, Neisseria spp., P. aeruginosa, O. uli, Hafnia alvei, Serratia marcescens and Filifactor alocis (p < 0.05). In contrast, Fusobacterium necrophorum, Lactobacillus acidophilus, Staphylococcus aureus and Streptococcus pneumoniae were associated with periodontal health (p < 0.05). Pathogenic species of medical importance may be detected in high prevalence and levels in the periodontal microbiota. Regardless of their role in periodontal health or disease, the periodontal biofilm may be a source for dissemination and development of systemic infections by these pathogenic microorganisms.

Assessment of adhesion, invasion and cytotoxicity potential of oral Staphylococcus aureus strains

The oral cavity is regarded as a relevant site for Staphylococcus aureus colonization. However, characterization of virulence mechanisms of oral S. aureus remains to be uncovered. In this study, twenty one S. aureus strains isolated from the oral cavity of Tunisian patients were screened for adherence, invasion and cytotoxicity against HeLa cells. In addition, the presence of adhesins (icaA, icaD, can, fnbA and fnbB) and α-hemolysin (hla) genes in each strain was achieved by polymerase chain reaction (PCR). Our finding revealed that oral S. aureus strains were able to adhere and invade epithelial cells, with variable degrees (P < 0.05). Moreover they exhibited either low (23.8%) or moderate (76.2%) cytotoxic effects. In addition 76.2% of strains were icaA and icaD positive and 90.5% harbor both the fnbA and the fnbB gene. While the cna gene was detected in 12 strains (57.2%). Furthermore, the hla gene encoding the α-toxin was found in 52.4% of the isolates. All these virulence factors give to S. aureus the right qualities to become a redoubtable pathogen associated to oral infections.

Long-term evaluation of the antimicrobial susceptibility and microbial profile of subgingival biofilms in individuals with aggressive periodontitis

This study evaluates the antimicrobial susceptibility and composition of subgingival biofilms in generalized aggressive periodontitis (GAP) patients treated using mechanical/antimicrobial therapies, including chlorhexidine (CHX), amoxicillin (AMX) and metronidazole (MET). GAP patients allocated to the placebo (C, n = 15) or test group (T, n = 16) received full-mouth disinfection with CHX, scaling and root planning, and systemic AMX (500 mg)/MET (250 mg) or placebos. Subgingival plaque samples were obtained at baseline, 3, 6, 9 and 12 months post-therapy from 3–4 periodontal pockets, and the samples were pooled and cultivated under anaerobic conditions. The minimum inhibitory concentrations (MICs) of AMX, MET and CHX were assessed using the microdilution method. Bacterial species present in the cultivated biofilm were identified by checkerboard DNA-DNA hybridization. At baseline, no differences in the MICs between groups were observed for the 3 antimicrobials. In the T group, significant increases in the MICs of CHX (p < 0.05) and AMX (p < 0.01) were detected during the first 3 months; however, the MIC of MET decreased at 12 months (p < 0.05). For several species, the MICs significantly changed over time in both groups, i.e., Streptococci MICs tended to increase, while for several periodontal pathogens, the MICs diminished. A transitory increase in the MIC of the subgingival biofilm to AMX and CHX was observed in GAP patients treated using enhanced mechanical therapy with topical CHX and systemic AMX/MET. Both protocols presented limited effects on the cultivable subgingival microbiota.

Pseudomonas aeruginosa and Periodontal Pathogens in the Oral Cavity and Lungs of Cystic Fibrosis Patients: a Case-Control Study

Cystic fibrosis (CF) is the most frequent lethal genetic disease in the Caucasian population. Lung destruction is the principal cause of death by chronic Pseudomonas aeruginosa colonization. There is a high prevalence of oropharyngeal anaerobic bacteria in sputum of CF patients. This study was carried out due to the lack of results comparing subgingival periodontal pathogenic bacteria between the oral cavity and lungs in patients with CF in relation with P. aeruginosa presence. Our first goal was to detect P. aeruginosa in oral and sputum samples by culture and molecular methods and to determine clonality of isolates. In addition, subgingival periodontal anaerobic bacteria were searched for in sputum. A cross-sectional pilot case-control study was conducted in the CF Reference Center in Roscoff, France. Ten CF patients with a ΔF508 homozygous mutation (5 chronically colonized [CC] and 5 not colonized [NC]) were enrolled. P. aeruginosa was detected in saliva, sputum, and subgingival plaque samples by real-time quantitative PCR (qPCR). Subsequently, periodontal bacteria were also detected and quantified in subgingival plaque and sputum samples by qPCR. In CC patients, P. aeruginosa was recovered in saliva and subgingival plaque samples. Sixteen P. aeruginosa strains were isolated in saliva and sputum from this group and compared by pulsed-field gel electrophoresis (PFGE). Subgingival periodontal anaerobic bacteria were found in sputum samples. A lower diversity of these species was recovered in the CC patients than in the NC patients. The presence of the same P. aeruginosa clonal types in saliva and sputum samples underlines that the oral cavity is a possible reservoir for lung infection.

Effects of Fixed and Removable Space Maintainers on Plaque Accumulation, Periodontal Health, Candidal and Enterococcus Faecalis Carriage

OBJECTIVE

To evaluate the effects of space maintainers on plaque accumulation, periodontal health and oral microflora.

SUBJECTS AND METHODS

The study participants comprised 38 patients aged 4-10 years requiring either fixed or removable space maintainers. Plaque index, gingival index, bleeding on probing index, candidal colonization and Enterococcus faecalis were recorded just before the application of space maintainers (T0) and during treatment at the 1st (T1), 3rd (T2) and 6th (T3) month.

RESULTS

The gingival and bleeding on probing index scores increased significantly (gingival index from 0.20 ± 0254 to 0.54 ± 0417 and bleeding on probing index from 7.18 ± 9.946 to 18.07 ± 14.074) in the regions with fixed space maintainers at T3 (p < 0.01). The mean Candida counts also increased (for removable appliances from 1.90 ± 3.638 to 1.98 ± 3.318, p < 0.05, and for fixed appliances from 4.25 ± 4.587 to 4.52 ± 4.431, p < 0.001). The salivary E. faecalis counts at T3 also increased significantly with the use of fixed and removable appliances (for removable appliances from 5.93 ± 2.65 to 85.53 ± 34.1 and for fixed appliances from 4.95 ± 2.94 to 123.59 ± 29.51, p < 0.001). A positive correlation was found between the plaque (r = 0.67), gingival (r = 0.76) and bleeding on probing index scores (r = 0.76) and the candidal colonization for the fixed space maintainers (p < 0.01, p < 0.001).

CONCLUSIONS

In this study, both fixed and removable space maintainers led to an increase in the number of microorganisms in the oral cavity as well as to increases in the periodontal index scores. Patients should be informed that space maintainers may serve as a source of infection and that special attention must be given to their oral hygiene.

On putative periodontal pathogens: an epidemiological perspective

The current understanding on the role of microbiology on periodontitis causation is reviewed. An appraisal of the literature reveals several issues that have limited the attempts to investigate candidate periodontal pathogens as causes of periodontitis and confirms that only limited epidemiological evidence is available. Several aspects of the contemporary understanding on causal inference are discussed with examples for periodontitis.

Code blue: Acinetobacter baumannii, a nosocomial pathogen with a role in the oral cavity

Actinetobacter baumannii is an important nosocomial pathogen that can cause a wide range of serious conditions including pneumonia, meningitis, necrotizing fasciitis and sepsis. It is also a major cause of wound infections in military personnel injured during the conflicts in Afghanistan and Iraq, leading to its popular nickname of 'Iraqibacter'. Contributing to its success in clinical settings is resistance to environmental stresses such as desiccation and disinfectants. Moreover, in recent years there has been a dramatic increase in the number of A. baumannii strains with resistance to multiple antibiotic classes. Acinetobacter baumannii is an inhabitant of oral biofilms, which can act as a reservoir for pneumonia and chronic obstructive pulmonary disease. Subgingival colonization by A. baumannii increases the risk of refractory periodontitis. Pathogenesis of the organism involves adherence, biofilm formation and iron acquisition. In addition, A. baumannii can induce apoptotic cell death in epithelial cells and kill hyphal forms of Candida albicans. Virulence factors that have been identified include pili, the outer membrane protein OmpA, phospholipases and extracellular polysaccharide. Acinetobacter baumannii can sense blue light through a blue-light sensing using flavin (BLUF) domain protein, BlsA. The resulting conformational change in BlsA leads to changes in gene expression, including virulence genes.

Prevalence of Pseudomonas aeruginosa and Acinetobacter spp. in subgingival biofilm and saliva of subjects with chronic periodontal infection

P. aeruginosa and Acinetobacter spp. are important pathogens associated with late nosocomial pneumonia in hospitalized and institutionalized individuals. The oral cavity may be a major source of these respiratory pathogens, particularly in the presence of poor oral hygiene and periodontal infection. This study investigated the prevalence of P. aeruginosa and Acinetobacter spp. in subgingival biofilm and saliva of subjects with periodontal disease or health. Samples were obtained from 55 periodontally healthy (PH) and 169 chronic periodontitis (CP) patients. DNA was obtained from the samples and detection of P. aeruginosa and Acinetobacter spp. was carried out by multiplex and nested PCR. P. aeruginosa and Acinetobacter spp. were detected in 40% and 45% of all samples, respectively. No significant differences in the distribution of these microorganisms between men and women, subgingival biofilm and saliva samples, patients ≤ 35 and > 35 years of age, and smokers and non-smokers were observed regardless periodontal status (p > 0.05). In contrast, the frequencies of P. aeruginosa and Acinetobacter spp. in saliva and biofilm samples were significantly greater in CP than PH patients (p < 0.01). Smokers presenting P. aeruginosa and high frequencies of supragingival plaque were more likely to present CP than PH. P. aeruginosa and Acinetobacter spp. are frequently detected in the oral microbiota of CP. Poor oral hygiene, smoking and the presence of P. aeruginosa are strongly associated with periodontitis.

Newly identified pathogens associated with periodontitis: a systematic review

There is substantial evidence supporting the role of certain oral bacteria species in the onset and progression of periodontitis. Nevertheless, results of independent-culture diagnostic methods introduced about a decade ago have pointed to the existence of new periodontal pathogens. However, the data of these studies have not been evaluated together, which may generate some misunderstanding on the actual role of these microorganisms in the etiology of periodontitis. The aim of this systematic review was to determine the current weight of evidence for newly identified periodontal pathogens based on the results of "association" studies. This review was conducted and reported in accordance with the PRISMA statement. The MEDLINE, EMBASE, and Cochrane databases were searched up to September 2013 for studies (1) comparing microbial data of subgingival plaque samples collected from subjects with periodontitis and periodontal health and (2) evaluating at least 1 microorganism other than the already-known periodontal pathogens. From 1,450 papers identified, 41 studies were eligible. The data were extracted and registered in predefined piloted forms. The results suggested that there is moderate evidence in the literature to support the association of 17 species or phylotypes from the phyla Bacteroidetes, Candidatus Saccharibacteria, Firmicutes, Proteobacteria, Spirochaetes, and Synergistetes. The phylum Candidatus Saccharibacteria and the Archaea domain also seem to have an association with disease. These data point out the importance of previously unidentified species in the etiology of periodontitis and might guide future investigations on the actual role of these suspected new pathogens in the onset and progression of this infection.

Molecular detection of bacteria associated to dental caries in 4-12-year-old Tunisian children

The occurrence of several microbial species in the oral cavity of 4-12-year-old Tunisian children was investigated. Samples were taken from 158 children (81 caries actives and 77 caries free). Genomic DNA was extracted and analyzed for the presence of 17 microbial species using a polymerase chain reaction assay. All samples were positive for at least one of the target microbial strains. Streptococcus mutans was the most prevalent species (76.5%) detected in genomic DNA collected from carious lesions. Other prevalent species were Candida spp (63%), Streptococcus salivarius (59%) and Streptococcus oralis (42%). The frequency of Lactobacillus acidophilus, Lactobacillus plantarum, and Lactobacillus casei-group in caries lesions was 29.5%, 34.5% and 22% respectively. Pathogenic bacteria such as Staphylococcus aureus was found in 28.5% of carious lesion samples compared to 15.5% in the control. Frequency of Porphyromonas endodontali, Actinomyces radicidentis and Treponema denticola recovery did not differ significantly between origins of samples. PCR analysis of genomic DNA detect various oral bacteria that differ between caries actives and caries-free children. In addition, the association of same aciduric bacteria (S. mutans, S. salivarius, L. acidophilus) and caries formation was noticed.

Lessons learned and unlearned in periodontal microbiology

Periodontal diseases are initiated by bacterial species living in polymicrobial biofilms at or below the gingival margin and progress largely as a result of the inflammation elicited by specific subgingival species. In the past few decades, efforts to understand the periodontal microbiota have led to an exponential increase in information about biofilms associated with periodontal health and disease. In fact, the oral microbiota is one of the best-characterized microbiomes that colonize the human body. Despite this increased knowledge, one has to ask if our fundamental concepts of the etiology and pathogenesis of periodontal diseases have really changed. In this article we will review how our comprehension of the structure and function of the subgingival microbiota has evolved over the years in search of lessons learned and unlearned in periodontal microbiology. More specifically, this review focuses on: (i) how the data obtained through molecular techniques have impacted our knowledge of the etiology of periodontal infections; (ii) the potential role of viruses in the etiopathogenesis of periodontal diseases; (iii) how concepts of microbial ecology have expanded our understanding of host-microbe interactions that might lead to periodontal diseases; (iv) the role of inflammation in the pathogenesis of periodontal diseases; and (v) the impact of these evolving concepts on therapeutic and preventive strategies to periodontal infections. We will conclude by reviewing how novel systems-biology approaches promise to unravel new details of the pathogenesis of periodontal diseases and hopefully lead to a better understanding of their mechanisms.

Effect of Scaling and Root Planing on Detection of Tannerella forsythia in Chronic Periodontitis

Aim. This study was aimed to determine the prevalence of Tannerella forsythia in subgingival plaque samples of chronic periodontitis patients having different level of periodontal destruction and to assess the effect of scaling and root planing (SRP) on prevalence of T. forsythia. Materials and Methods. Study included 3 groups: group 1 were healthy individuals, group 2 had periodontitis with probing depth ≤ 5 mm, and group 3 had periodontitis with probing depth > 5 mm. Subjects in groups 2 and 3 exhibited both healthy and diseased periodontal sites. Prevalence of T. forsythia was determined using polymerase chain reaction. Subjects in groups 2 and 3 received SRP and were reevaluated three months after SRP. Results. T. forsythia was not detected in group 1. It was found in diseased sites in 40% and 73.33% of patients from groups 2 and 3, respectively. It was also found in healthy sites in 6.67% and 13.33% of patients from groups 2 and 3, respectively. The detection frequency of T. forsythia after SRP was 6.67% and 13.33% in groups 2 and 3, respectively. Conclusion. The results indicate a possible association between periodontal disease and presence of T. forsythia. Also, the detection frequency of T. forsythia was reduced after SRP.

Microbiological diversity of peri-implantitis biofilm by Sanger sequencing

BACKGROUND AND OBJECTIVE

To examine the microbial diversity associated with implants with or without peri-implantitis and to identify differences between the bacterial communities in these clinical conditions.

MATERIAL AND METHODS

Twenty subjects were assigned to a Control group consisting of subjects with healthy implants and a Test group consisting of subjects with peri-implantitis sites, as well as a healthy implant site (n = 10/group). In the Test group, subgingival biofilm samples were taken from the deepest sites of the diseased implant. In both groups, samples were collected from one site around a healthy implant. DNA was extracted and the 16S rRNA gene was amplified and sequenced, and the phylotypes were identified by comparison with known 16S rRNA sequences.

RESULTS

The phylogenetic identity of 1387 16S rRNA gene clones was determined. Healthy implants demonstrated higher proportions of Actinomyces, Atopobium, Gemella, Kingella and Rothia and lower levels of Campylobacter, Desulfobulbus, Dialister, Eubacterium, Filifactor, Mitsukella, Porphyromonas and Pseudoramibacter (Mann-Whitney U-test; P < 0.05). Fusobacterium nucleatum, Dialister invisus, Streptococcus sp. human oral taxon (HOT) 064, Filifactor alocis and Mitsuokella sp. HOT 131 presented a higher mean proportion, while Veillonella dispar, Actinomyces meyeri, Granulicatella adiacens showed lower mean proportions in the peri-implantitis sites when compared with healthy implants in both the Control and Test groups (Mann-Whitney U-test; P < 0.05).

CONCLUSION

Marked differences were observed in the composition of the subgingival biofilm between healthy and diseased implants. The biofilm associated with peri-implantitis harbored more pathogenic bacterial species from the orange complex and other "unusual" putative pathogens, such as F. alocis, D. invisus and Mitsuokella sp. HOT 131.

Quantitative detection of Staphylococcus aureus, Enterococcus faecalis and Pseudomonas aeruginosa in human oral epithelial cells from subjects with periodontitis and periodontal health

Epithelial cells in oral cavities can be considered reservoirs for a variety of bacterial species. A polymicrobial intracellular flora associated with periodontal disease has been demonstrated in buccal cells. Important aetiological agents of systemic and nosocomial infections have been detected in the microbiota of subgingival biofilm, especially in individuals with periodontal disease. However, non-oral pathogens internalized in oral epithelial cells and their relationship with periodontal status are poorly understood. The purpose of this study was to detect opportunistic species within buccal and gingival crevice epithelial cells collected from subjects with periodontitis or individuals with good periodontal health, and to associate their prevalence with periodontal clinical status. Quantitative detection of total bacteria and Staphylococcus aureus, Pseudomonas aeruginosa and Enterococcus faecalis in oral epithelial cells was determined by quantitative real-time PCR using universal and species-specific primer sets. Intracellular bacteria were visualized by confocal microscopy and fluorescence in situ hybridization. Overall, 33% of cell samples from patients with periodontitis contained at least one opportunistic species, compared with 15% of samples from healthy individuals. E. faecalis was the most prevalent species found in oral epithelial cells (detected in 20.6% of patients with periodontitis, P = 0.03 versus healthy individuals) and was detected only in cells from patients with periodontitis. Quantitative real-time PCR showed that high levels of P. aeruginosa and S. aureus were present in both the periodontitis and healthy groups. However, the proportion of these species was significantly higher in epithelial cells of subjects with periodontitis compared with healthy individuals (P = 0.016 for P. aeruginosa and P = 0.047 for S. aureus). Although E. faecalis and P. aeruginosa were detected in 57% and 50% of patients, respectively, with probing depth and clinical attachment level ≥6 mm, no correlation was found with age, sex, bleeding on probing or the presence of supragingival biofilm. The prevalence of these pathogens in epithelial cells is correlated with the state of periodontal disease.

Prevalence of Candida spp. during radiographic examination in Diabetes mellitus patients

INTRODUCTION: It is suggested that individuals with diabetes are more susceptible to Candida infections than healthy people, especially if periodontal infection is associated. OBJECTIVE: This study evaluated the prevalence of colonization by Candida spp. during radiographic examination in diabetic and non-diabetic patients. MATERIAL AND METHODS: Twenty-six patients with type 2 diabetes mellitus and 20 patients without diabetes mellitus, presenting chronic periodontitis and presence of Candida spp. in saliva were evaluated. During radiographic examination, samples of saliva were collected from: oral mucosa, conventional radiographic periapical film, digital x-ray sensor (CDR), and bite block of the receptor-positioning device. Colony forming units (cfu/mL) and identification of Candida yeasts were assessed. RESULT: Oral mucosa from both groups showed the highest colonization with Candida spp. if compared with others surfaces collected (p < 0.05). In diabetic patients, the mucosa of the upper left regions showed higher levels of colonization. In non-diabetic patients, the upper right molar region showed the highest level of colonization during the examination of the receptor-positioning device, the sensor and the non-sensitive film. Candida spp. levels in saliva were similar between diabetics (mean = 3.0 × 10(6)) and non-diabetics (mean = 3.8 × 10(6)). CONCLUSION: No difference in Candida spp. colonization (cfu/mL) in diabetics and non-diabetic patients was observed for the five collected surfaces and the simulated radiographic region. Candida albicans was the prevalent species of Candida spp. found on all the samples.