Quantitative analysis of periodontal pathogens present in the saliva of geriatric subjects

Real-Time PCR Method as Diagnostic Tool for Detection of Periodontal Pathogens in Patients with Periodontitis

The most common type of periodontal disease is chronic periodontitis, an inflammatory condition caused by pathogenic bacteria in subgingival plaque. The aim of our study was the development of a real-time PCR test as a diagnostic tool for the detection and differentiation of five periodontopathogenic bacteria, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia, and Treponema denticola, in patients with periodontitis. We compared the results of our in-house method with the micro-IDent® semiquantitative commercially available test based on the PCR hybridization method. DNA was isolated from subgingival plaque samples taken from 50 patients and then analyzed by both methods. Comparing the results of the two methods, they show a specificity of 100% for all bacteria. The sensitivity for A. actinomycetemcomitans was 97.5%, for P. gingivalis 96.88%, and for P. intermedia 95.24%. The sensitivity for Tannerella forsythia and T. denticola was 100%. The Spearman correlation factor of two different measurements was 0.976 for A. actinomycetemcomitans, 0.967 for P. gingivalis, 0.949 for P. intermedia, 0.966 for Tannerella forsythia, and 0.917 for T. denticola. In conclusion, the in-house real-time PCR method developed in our laboratory can provide information about relative amount of five bacterial species present in subgingival plaque in patients with periodontitis. It is likely that such a test could be used in dental diagnostics in assessing the efficacy of any treatment to reduce the bacterial burden.

Bacteria-Mediated Oncogenesis and the Underlying Molecular Intricacies: What We Know So Far

Cancers are known to have multifactorial etiology. Certain bacteria and viruses are proven carcinogens. Lately, there has been in-depth research investigating carcinogenic capabilities of some bacteria. Reports indicate that chronic inflammation and harmful bacterial metabolites to be strong promoters of neoplasticity. Helicobacter pylori-induced gastric adenocarcinoma is the best illustration of the chronic inflammation paradigm of oncogenesis. Chronic inflammation, which produces excessive reactive oxygen species (ROS) is hypothesized to cause cancerous cell proliferation. Other possible bacteria-dependent mechanisms and virulence factors have also been suspected of playing a vital role in the bacteria-induced-cancer(s). Numerous attempts have been made to explore and establish the possible relationship between the two. With the growing concerns on anti-microbial resistance and over-dependence of mankind on antibiotics to treat bacterial infections, it must be deemed critical to understand and identify carcinogenic bacteria, to establish their role in causing cancer.

Toward Personalized Oral Diagnosis: Distinct Microbiome Clusters in Periodontitis Biofilms

Periodontitis is caused by pathogenic subgingival microbial biofilm development and dysbiotic interactions between host and hosted microbes. A thorough characterization of the subgingival biofilms by deep amplicon sequencing of 121 individual periodontitis pockets of nine patients and whole metagenomic analysis of the saliva microbial community of the same subjects were carried out. Two biofilm sampling methods yielded similar microbial compositions. Taxonomic mapping of all biofilms revealed three distinct microbial clusters. Two clinical diagnostic parameters, probing pocket depth (PPD) and clinical attachment level (CAL), correlated with the cluster mapping. The dysbiotic microbiomes were less diverse than the apparently healthy ones of the same subjects. The most abundant periodontal pathogens were also present in the saliva, although in different representations. The single abundant species Tannerella forsythia was found in the diseased pockets in about 16–17-fold in excess relative to the clinically healthy sulcus, making it suitable as an indicator of periodontitis biofilms. The discrete microbial communities indicate strong selection by the host immune system and allow the design of targeted antibiotic treatment selective against the main periodontal pathogen(s) in the individual patients.

Microbial profile in different orthodontic appliances by checkerboard DNA-DNA hybridization: An in-vivo study

INTRODUCTION

The design of the orthodontic bracket or appliance is 1 of the most important factors for creating retentive areas for biofilm formation. In orthodontics, this would be the first study to compare the microbial level changes in 3 different types of orthodontic appliances using checkerboard DNA-DNA hybridization technique. The purpose of this study was to evaluate and compare the extent of appearance of orange and red microbial complexes in patients undergoing orthodontic treatment using aligners, conventional metallic fixed labial appliances, and lingual fixed appliances.

METHODS

A total of 60 patients, of which 20 patients were undergoing treatment with aligners, 20 patients with labial fixed appliances, and 20 patients with lingual fixed appliances, were included in our study. After 30 days, debonded brackets and rinsed aligners were stored and processed for analysis with checkerboard DNA-DNA hybridization.

RESULTS

Most bacterial species showed moderate counts, with the exception of Treponema denticola, which showed a higher count in all 3 types of appliances. Fusobacterium nucleatum, Porphyromonas gingivalis, and T denticola were present in a higher percentage in the lingual appliance. Fusobacterium periodontium and Prevotella intermedia were present in a higher percentage in the labial fixed appliance. Campylobacter rectus, Tannerella forsythia, and Prevotella melaninogenica counts were moderate in all 3 appliances, with the first 2 microbes showing slightly higher counts in aligners. The association between all the microorganisms were statistically insignificant, with the exception of F nucleatum, which showed a strong statistically significant association in all 3 types of appliances.

CONCLUSIONS

The microbial contamination in metallic brackets was higher than that of aligners, when used for a month. Lingual fixed appliances showed more microbial contamination than labial fixed appliances followed by aligners.

Is a fusobacterium nucleatum infection in the colon a risk factor for colorectal cancer?: a systematic review and meta-analysis protocol

BACKGROUND

Despite a considerable amount of epidemiological research for identification of risk factors involved in the development of colorectal cancer, the current understanding of the etiology of this disease remains rather poor. Accumulating evidence suggests a potentially important role of infection with Fusobacterium nucleatum in the colon in colorectal carcinogenesis. The objective of this systematic review is to synthesize the epidemiological evidence on the association between infection with Fusobacterium nucleatum in the colon and colorectal cancer.

METHODS

This systematic review will include observational studies (cohort, case-control, cross-sectional) in humans in which the role of Fusobacterium nucleatum in the etiology of colorectal cancer was investigated. MEDLINE, EMBASE, Web of Science, and Cochrane Database of Systematic Reviews will be searched using a comprehensive search strategy and manual screening of references. Two reviewers will independently identify eligible studies and extract the data from the included studies. The quality of studies will be assessed by using the Newcastle-Ottawa scale. Random-effects models will be used to estimate pooled measures of association (where feasible). Meta-regression and subgroup analyses will be conducted to explore the potential sources of heterogeneity. The Meta-Analysis of Observational Studies in Epidemiology (MOOSE) guidelines and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement will be followed for reporting.

DISCUSSION

Deepening knowledge regarding the etiology of colorectal cancer and the potential implications of Fusobacterium nucleatum in this disease is instrumental for prevention, diagnosis, and treatment of this often-fatal disease. This review will produce summarized current evidence on this topic.

SYSTEMATIC REVIEW REGISTRATION

This systematic review protocol has been registered with the International Prospective Register of Systematic Reviews (PROSPERO) on 10 July 2018 (registration number CRD42018095866).

Real-time PCR quantification of 9 periodontal pathogens in saliva samples from periodontally healthy Korean young adults

Purpose

Few studies have examined periodontal pathogens from saliva samples in periodontally healthy young adults. The purposes of this study were to determine the prevalence of periodontopathic bacteria and to quantify periodontal pathogens in saliva samples using real-time polymerase chain reaction (PCR) assays in periodontally healthy Korean young adults under 35 years of age.

Methods

Nine major periodontal pathogens were analyzed by real-time PCR in saliva from 94 periodontally healthy young adults. Quantification of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Prevotella intermedia, Fusobacterium nucleatum, Campylobacter rectus, Peptostreptococcus anaerobius, and Eikenella corrodens was performed by DNA copy number measurement.

Results

F. nucleatum and E. corrodens were detected in all subjects; the numbers of positive samples were 87 (92.6%), 91 (96.8%), and 90 (95.7%) for P. gingivalis, P. anaerobius, and C. rectus, respectively. Other pathogens were also detected in periodontally healthy subjects. Analysis of DNA copy numbers revealed that the most abundant periodontal pathogen was F. nucleatum, which was significantly more prevalent than all other bacteria (P<0.001), followed by P. anaerobius, P. gingivalis, E. corrodens, C. rectus, and T. denticola. There was no significant difference in the prevalence of each bacterium between men and women. The DNA copy number of total bacteria was significantly higher in men than in women.

Conclusions

Major periodontal pathogens were prevalent in the saliva of periodontally healthy Korean young adults. Therefore, we suggest that the development of periodontal disease should not be overlooked in periodontally healthy young people, as it can arise due to periodontal pathogen imbalance and host susceptibility.

Profiling of subgingival plaque biofilm microbiota in adolescents after completion of orthodontic therapy

Background

Fixed orthodontic treatment is the most common method for malocclusion but has the potential risk of periodontal complication with unclear outcomes of whether microbiologic and clinical changes could be reversible in adolescents after orthodontic therapy.

Methods

Twenty adolescents with orthodontic treatment were enrolled in the study as the case group at end of the therapy, while 19 periodontally healthy adolescents were involved in the control group. At baseline (T₀), clinical parameters including gingival index, probing depth and sulcus bleeding index were tested, and subgingival plaque samples were collected from the lower incisors. The counts of A. actinomycetemcomitans, P. gingivalis, P. intermedia, T. forsythia and total bacteria were determined by real-time PCR. All parameters were reassessed after 1 month (T₁) and 3 months (T₂) in the case group and compared with that of the controls.

Results

At baseline (T₀), clinical parameters (including GI, PD, SBI) of the test sites in the case group were significantly higher than that of the control group (P<0.05 or P<0.01). At 3 months (T₂), no differences were noticed in GI and SBI between two groups. The prevalence and counts of periodontopathogens tend to be normal (P>0.05), while PD and the amount of P.intermedia were still significantly higher compared with that of the control group (P<0.05 or P<0.01).

Conclusion

After removal of appliances, the periodontal changes induced by orthodontic therapy are only partially reversible at 3 months after removal.

Changes in salivary periodontal pathogens after orthodontic treatment: An in vivo prospective study

OBJECTIVE

  To analyze the initial changes in salivary levels of periodontal pathogens after orthodontic treatment with fixed appliances.

MATERIALS AND METHODS

  The subjects consisted of 54 adult patients. The Simplified Oral Hygiene Index, Plaque Index, and Gingival Index were measured as periodontal parameters. Both the plaque and gingival indexes were obtained from the central and lateral incisors and first molars of both arches. Whole saliva and periodontal parameters were obtained at the following four time points: immediately before debonding (T1), 1 week after debonding (T2), 5 weeks after debonding (T3), and 13 weeks after debonding (T4). Repeated measures analysis of variance was used to determine salivary bacterial levels and periodontal parameters among the four time points after quantifying salivary levels of Aggregatibacter actinomycetemcomitans (Aa), Fusobacterium nucleatum (Fn), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), Tannerella forsythia (Tf), and total bacteria using the real-time polymerase chain reaction.

RESULTS

  All periodontal parameters were significantly decreased immediately after debonding (T2). The salivary levels of total bacteria and Pg were decreased at T3, while Pi and Tf levels were decreased at T4. However, the amount of Aa and Fn remained at similar levels in saliva during the experimental period. Interestingly, Aa and Fn were present in saliva at higher levels than were Pg, Pi, and Tf.

CONCLUSION

  The higher salivary levels of Aa and Fn after debonding suggests that the risk of periodontal problems cannot be completely eliminated by the removal of fixed orthodontic appliances during the initial retention period, despite improved oral hygiene.

Humoral immune responses to periodontal pathogens in the elderly

PURPOSE

Elderly people are thought to be more susceptible to periodontal disease due to reduced immune function associated with aging. However, little information is available on the nature of immune responses against putative periodontal pathogens in geriatric patients. The purpose of this study was to evaluate the serum IgG antibody responses to six periodontal pathogens in geriatric subjects.

METHODS

The study population consisted of 85 geriatric patients and was divided into three groups: 29 mild (MCP), 27 moderate (MoCP) and 29 severe (SCP) chronic periodontitis patients. Serum levels of IgG antibody to Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum and Prevotella intermedia were measured by enzyme-linked immunosorbent assay (ELISA) and compared among the groups.

RESULTS

All three groups showed levels of serum IgG in response to P. gingivalis, A. actinomycetemcomitans, and P. intermedia that were three to four times higher than levels of IgG to T. forsythia, T. denticola, and F. nucleatum. There were no significant differences among all three groups in IgG response to P. gingivalis (P=0.065), T. forsythia (P=0.057), T. denticola (P=0.1), and P. intermedia (P=0.167), although the IgG levels tended to be higher in patients with SCP than in those with MCP or MoCP (with the exception of those for P. intermedia). In contrast, there were significant differences among the groups in IgG levels in response to F. nucleatum (P=0.001) and A. actinomycetemcomitans (P=0.003). IgG levels to A. actinomycetemcomitans were higher in patients with MCP than in those with MoCP or SCP.

CONCLUSIONS

When IgG levels were compared among three periodontal disease groups, only IgG levels to F. nucleatum significantly increased with the severity of disease. On the contrary, IgG levels to A. actinomycetemcomitans decreased significantly in patients with SCP compared to those with MCP. There were no significant differences in the IgG levels for P. gingivalis, T. forsythia, T. denticola, and P. intermedia among geriatric patients with chronic periodontitis.