Quantitative Analysis of Periodontal Pathogens Using Real-Time Polymerase Chain Reaction (PCR)

Gut bacteriome dynamics in high altitude-adapted chicken lines: a key to future poultry therapeutics

High-altitude-adapted chickens harbor a unique gut bacteriome essential for their survival under extremely cold and hypoxic environment, however, little is known about their population and functional dynamics, limiting their application in poultry production. Hence, this study employed amplicon-based metagenomics to examine the gut bacterial diversity and their functional profile in two high-altitude-adapted chicken lines, e.g. LEHBRO-1 and LEHBRO-3. The results revealed significant variations in taxonomic abundance at the phylum level, with Firmicutes, Proteobacteria, Bacteroidetes, and Actinobacteria predominating in LEHBRO-1, whereas Firmicutes, Proteobacteria, Bacteroidetes, Planctomycetes, and Actinobacteria predominated in LEHBRO-3. Genus-level diversity and Linear Discriminant Analysis Effect Size (LEfSe) biomarker analysis also substantiated the differences in the gut bacterial communities between the two chicken lines. Furthermore, functional profiling revealed enrichment of carbohydrate, nucleotide, lipid, amino acid, fatty acid, energy, and glycan metabolic pathways in the gut bacteriomes of these high-altitude chicken lines. The Statistical Analysis of Metagenomic Profiles (STAMP) for metabolic profiling identified a significant difference in purine and protein metabolism between these two chicken lines. These findings indicate the unique gut bacteriome and their functional diversity in high-altitude-adapted chickens, which would provide a foundation for future research on gut therapeutics to improve chicken health and productivity in high-altitude areas.

Detection and quantification of pathogens in saliva of adolescents with cerebral palsy: a cross-sectional study

Background

Elevated levels of inflammatory mediators in saliva have been described in individuals with cerebral palsy (CP).

Objective

The aim of this study was to detect and quantify the pathogens Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum and Prevotella intermedia in the saliva of adolescents with CP.

Methods

This is a cross-sectional study with adolescents with CP to detect periodontopathogens from saliva samples. Initially, saliva was collected from the CP (n = 34) and control groups (n = 31), followed by the gingival index (GI) for distribution of the groups of individuals with CP and control with gingivitis (bleeding on probing ≥ 10%) and without gingivitis. Bacterial DNA was extracted from saliva samples for detection of periodontopathogens by quantitative PCR (q-PCR). Data were analyzed by Mann-Whitney and Kruskal-Wallis tests, analysis of variance t-test (ANOVA) with Tukey-Kramer post-hoc tests (p < 0.05).

Results

The quantification of DNA of periodontopathogens in saliva samples showed that adolescents with CP present a variability (22.93-39.56) in the detection of P. gingivalis and that some subjects with CP and gingivitis (n = 4) present high quantification of P. gingivalis (ranging 39.56-37.65), although no significant difference was found between the groups (p > 0.05). A significant contrast was observed for the pathogen P. intermedia when comparing the difference in the control group (p = 0.0396). No major differences were detected in the quantification of periodontopathogens evaluated between the control group and CP.

Conclusion

Adolescents with CP showed variability in the detection of DNA of periodontopathogens, especially a great variation in the detection of P gingivalis in saliva of CP with gingivitis.

Dynamic analysis of Porphyromonas gingivalis invasion into blood capillaries during the infection process in host tissues using a vascularized three-dimensional human gingival model

Porphyromonas gingivalis, the pathogen of periodontal disease, is thought to be involved in various diseases throughout the body via gingival tissue blood capillaries. However, the dynamic analysis of the infection mechanism, particularly the deep invasion process of the gingival tissue, has not yet been elucidated because of the lack of both in vivo and in vitro models. In this study, we developed a vascularized three-dimensional (3D) gingival model with an epithelial barrier expressing cell-cell junctions using collagen microfibers (CMFs) to enable the dynamic analysis of the P. gingivalis invasion process. Lipid raft disruption experiments in the gingival epithelial cell layer demonstrated that P. gingivalis migrates into the deeper epithelium via the intercellular pathway rather than intracellular routes. P. gingivalis was shown to invade the 3D gingival model, being found inside blood capillaries during two days of culture. Notably, the number of bacteria had increased greatly at least two days later, whereas the mutant P. gingivalis lacking the cysteine proteases, gingipains, showed a significantly lower number of survivors. The secretion of interleukin-6 (IL-6) from the gingival tissue decreased during the two days of infection with the wild type P. gingivalis, but the opposite was found for the mutant suggesting that P. gingivalis infection disturbs IL-6 secretion at an early stage. By allowing the dynamic observation of the P. gingivalis invasion from the epithelial cell layer into the blood capillaries for the first time, this model will be a powerful tool for the development of novel therapeutics against periodontal infection related diseases.

Clinical, inflammatory and microbiological outcomes of full-mouth scaling with adjunctive glycine powder air-polishing: A randomized trial

AIM

To determine the effects of glycine powder air-polishing (GPAP) as an adjunct to full-mouth scaling and root planing (SRP) on clinical, inflammatory and microbiological outcomes in patients with untreated periodontitis.

MATERIALS AND METHODS

Forty-one patients were randomly assigned to the control group A (SRP) and test groups B1 (subgingival GPAP right after SRP) and B2 (subgingival GPAP right before SRP). Clinical examinations and sample collections (saliva, subgingival plaque, serum and gingival crevicular fluid) were performed at assessment visits and before therapies at clinical visits of baseline, 6-week and 3-month. C-reactive protein, IL-6 and TNF-α were assessed in serum and gingival crevicular fluid, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans and Fusobacterium nucleatum were measured in saliva and subgingival plaque.

RESULTS

Patients in control and test groups did not significantly differ by age, sex and disease severity at baseline. Participants in control and intervention groups had similar improvements in clinical parameters (PD, BOP, PLI and BI). All groups had a similar percentage of sites showing PD reduction of ≥2 mm between baseline and follow-up visits, with a few exceptions. Reduced C-reactive protein, IL-6 and TNF-α in serum were found after treatments.

CONCLUSION

Full-mouth SRP with and without GPAP resulted in largely similar clinical, inflammatory and microbiological outcomes in the care of untreated periodontitis.

Prevalence of Aggregatibacter actinomycetemcomitans and Periodontal Findings among 14 to 15-Year Old Danish Adolescents: A Descriptive Cross-Sectional Study

Aggregatibacter actinomycetemcomitans (Aa) is a keystone pathogen associated with periodontitis in adolescents. The knowledge on the prevalence of Aa and periodontitis among adolescents in Northern Europe is sparse. A total of 525 14- to 15-year-old adolescents from the municipality of Aarhus, Denmark, underwent a full-mouth clinical examination. Plaque score (PS), bleeding on probing (BOP), probing pocket depth (PPD), and clinical attachment loss (CAL) were recorded. Subgingival plaque samples (SPS) and stimulated saliva samples (SSS) were collected and analyzed for the presence of JP2 and non-JP2 genotypes of Aa using real-time PCR. A total of 70 (13.3%) individuals were positive for Aa, with 17 found in SPS, 19 in SSS, and 35 in both. The highly leukotoxic JP2 genotype of Aa was not detected. The individuals positive for Aa in both SPS and SSS had poorer periodontal outcomes (PPD and CAL) than individuals without Aa and individuals carrying Aa in either SPS or SSS only. In conclusion, 13% of 14- to 15-year-old Danish adolescents were positive for Aa, and the presence of Aa in both SPS and SSS was associated with poorer periodontal outcomes.

Compressed Air-Driven Continuous-Flow Thermocycled Digital PCR for HBV Diagnosis in Clinical-Level Serum Sample Based on Single Hot Plate

We report a novel compressed air-driven continuous-flow digital PCR (dPCR) system based on a 3D microfluidic chip and self-developed software system to realize real-time monitoring. The system can ensure the steady transmission of droplets in long tubing without an external power source and generate stable droplets of suitable size for dPCR by two needles and a narrowed Teflon tube. The stable thermal cycle required by dPCR can be achieved by using only one constant temperature heater. In addition, our system has realized the real-time detection of droplet fluorescence in each thermal cycle, which makes up for the drawbacks of the end-point detection method used in traditional continuous-flow dPCR. This continuous-flow digital PCR by the compressed air-driven method can meet the requirements of droplet thermal cycle and diagnosis in a clinical-level serum sample. Comparing the detection results of clinical samples (hepatitis B virus serum) with commercial instruments (CFX Connect; Bio Rad, Hercules, CA, USA), the linear correlation reached 0.9995. Because the system greatly simplified the traditional dPCR process, this system is stable and user-friendly.

Innovative application of nested PCR for detection of Porphyromonas gingivalis in human highly calcified atherothrombotic plaques

Atherothrombosis, leading to stroke and myocardial infarction, is responsible for most of the deaths in the world. An increased risk of atherothrombotic vascular events has been reported in patients with periodontitis. Periodontitis is a chronic multifactorial inflammatory disease, which involves a dysbiotic microbiota, and leads to a progressive destruction of the tooth-supporting apparatus. Transcient periodontal pathogen blood translocation, mainly bacteremia, has been associated with the severity of gingival inflammation. The identification of periodontal bacteria within atherothrombotic plaques is challenging and unpredictable. This review aims to summarize existing molecular technics for identifying periodontal microbiota in human atherothrombotic samples. A secondary objective is to describe a protocol for the identification of Porphyromonas gingivalis from highly calcified, atherothrombotic human samples that is based on our experience in translational cardiovascular research. Compared to direct real-time PCR, our protocol based on nested PCR has increased the detection of Porphyromonas gingivalis by 22.2% with good specificity.

H2S mediates increased interleukin (IL)-1β and IL-18 production in leukocytes from patients with periodontitis

Background: The mechanisms involved in the interplay between the bacteria and the host cells in periodontitis are not fully understood.

Aim: To investigate the effect of the bacterial metabolite H₂S on the pro-inflammatory cytokines interleukin (IL)-1β and IL-18 from periodontitis patients and healthy controls, and to evaluate the composition of the subgingival microbiota with its capacity to produce H₂S.

Methods: Subgingival bacterial samples from patients with periodontitis (N=32) and healthy controls (N=32) were investigated for H₂S production and bacterial composition. Peripheral blood mononuclear cells (PBMCs) were cultured in the presence/absence of 1mM H₂S for 24h and cytokine concentrations were measured.

Results: Subgingival plaque from periodontitis patients had more H₂S producing bacteria and produced more H₂S, than healthy controls. PBMCs exposed to H₂S secreted significantly more IL-1ß and IL-18 (p<0.0001) than untreated control PBMCs from both groups. PBMCs from the periodontitis patients secreted higher levels of the cytokines, both spontaneously (IL-1ß p=0.0001; IL-18 p=0.09) and after exposure to H₂S (IL-1ß p=0.03; IL-18 p=0.04), which is a new finding not previously reported.

Conclusions: H₂S, from the subgingival microbiota, can contribute to a host inflammatory response through secretion of the pro-inflammatory cytokines IL-1β and IL-18. Since this response differs between individuals, it may also reflect the susceptibility of the host to develop periodontitis.