Detection of Helicobacter pylori by polymerase chain reaction in the subgingival biofilm and saliva of non-dyspeptic periodontal patients

New putative periodontopathogens and periodontal health-associated species: A systematic review and meta-analysis

To investigate the existence of any association between new putative periodontal pathogens and periodontitis. Two independent reviewers conducted electronic literature searches in the MEDLINE (PubMed), EMBASE, DOSS and Google Scholar databases as well as a manual search to identify eligible clinical studies prior to November 2022. Studies comparing the prevalence of microorganisms other than the already-known periodontal pathogens in subgingival plaque and/or saliva samples between subjects with periodontitis and subject with periodontal health were included. Meta-analyses were performed on data provided by the included studies. Fifty studies including a total of 2739 periodontitis subjects and 1747 subjects with periodontal health were included. The Archaea domain and 25 bacterial species (Anaeroglobus geminatus, Bacteroidales [G-2] bacterium HMT 274, Desulfobulbus sp. HMT 041, Dialister invisus, Dialister pneumosintes, Eubacterium brachy, Enterococcus faecalis, Eubacterium nodatum, Eubacterium saphenum, Filifactor alocis, Fretibacterium sp. HMT 360, Fretibacterium sp. HMT 362, Mogibacterium timidum, Peptoniphilaceae sp. HMT 113, Peptostreptococcus stomatis, Porphyromonas endodontalis, Slackia exigua, Streptococcus gordonii, Selenomonas sputigena, Treponema amylovorum, Treponema lecithinolyticum, Treponema maltophilum, Treponema medium, Treponema parvum and Treponema socranskii) were found to be statistically significantly associated with periodontitis. Network studies should be conducted to investigate the role of these newly identified periodontitis-associated microorganisms through interspecies interaction and host-microbe crosstalk analyses.

The association between periodontal diseases and helicobacter pylori: an updated meta-analysis of observational studies

INTRODUCTION

Various studies have examined the association between periodontitis and helicobacter pylori and reported conflicting results. The aimed of this systematic review and meta-analysis estimating the association between these two variables.

METHODS

Electronic databases including PubMed (Medline), Scopus, Web of Sciences and Medline (Elsevier) were searched using the relevant keywords. All observational studies comparing the association between periodontitis and helicobacter pylori were considered. The Newcastle - Ottawa Quality Assessment Scale (NOS) checklist was used for assessing quality of included studies. All statistical analyses were completed using STATA (Version 16).

RESULTS

Twenty-three studies with 8,638 patients (15 case-control with 2,366 patients and 8 cross-sectional with 6,272 patients) were included in this meta-analysis. After combining the selected studies, the odds of presence the Helicobacter pylori infection in patients with the periodontal disease was 2.47 (OR: 2.47; 95% CI: 2.01, 3.03; I²: 50.87%; P: 0.001). Also, the odds after combining case-control studies was 2.77 (OR: 2.77; % 95 CI: 2.11, 3.66; I²: 37.16%; P: 0.049) and after combining cross-sectional analytical ones, it was equal to 2.07 (OR: 2.07; 95% CI: 1.62, 2.65; I²: 43.25%; P: 0.050).

CONCLUSION

Based on the results of this meta-analysis, the association between Helicobacter pylori infection and the periodontal disease is evident.

The Association of Helicobacter pylori in the Oral Cavity With Dental Caries in Patients With and Without Gastric Infection: A Systematic Review

Helicobacter pylori (H. pylori) organisms are well-recognized pathogens responsible for many GI diseases. Streptococcus mutans-related caries and H. pylori infection share similar risk factors such as early childhood occurrence and low socioeconomic status. Therefore, it is possible for these two bacterial diseases to co-exist in the same environment. The present review evaluates the association of H. pylori with dental caries in patients with and without gastric infection, with the objective of comparing the association of H. pylori with dental caries in patients with and without gastric infection. A computerized literature search was performed in online databases from September 2000 to September 2022 using both electronic and manual searches for scientific databases. The research question was framed following the patient/population, intervention, comparison, and outcomes (PICO) statement. A thorough literature search identified a total of 200 manuscripts. Out of which, 100 were duplicate records and 100 were screened for eligibility, and about 78 articles were excluded, as they were not following PICO and the eligibility criterion. The retrieved 22 articles were sought for retrieval, only 17 were retrieved, and two studies did not fulfill the requirement. A total of 15 studies were recorded as eligible for the present review. There is a close association between the presence of infection of H. pylori in the oral cavity and the increased number of dental caries incidence in patients, even without a gastric infection. This suggests that the oral cavity is another niche for H. Pylori and may be the source of infection, re-infection, and transmission into the stomach.

Porphyromonas gingivalis-Helicobacter pylori co-incubation enhances Porphyromonas gingivalis virulence and increases migration of infected human oral keratinocytes

Background

Porphyromonas gingivalis is part of the subgingival biofilm and a keystone species in the development of periodontitis. Interactions between P.gingivalis and other bacteria in biofilms have been shown to affect bacterial virulence. Helicobacter pylori also inhabits the subgingival biofilm, but the consequences of interactions there with P.gingivalis remain unknown. Here, we investigated how the pre-incubation of P.gingivalis with H.pylori affects P.gingivalis virulence.

Methods

We assayed P.gingivalis internalization by oral keratinocytes (OKs), hemagglutination and biofilm formation to identify alterations in virulence after pre-incubation with H. pylori. Also, we evaluated viability and migration of OKs infected with P. gingivalis, as well as the role of toll-like receptor 4 (TLR4).   In addition, we quantified the mRNA of genes associated with P.gingivalis virulence.

Results

Pre-incubation of P.gingivalis with H.pylori enhanced P.gingivalis biofilm formation, bacterial internalization into OKs and hemagglutination. Infection with pre-incubated P.gingivalis increased OK migration in a manner dependent on the O-antigen and linked to  increased expression of the gingipain RgpB. Also, OK TLR4 participates in these events, because upon TLR4 knock-down, pre-incubated P.gingivalis no longer stimulated OK migration.

Discussion

We provide here for the first time insight to the consequences of direct interaction between P.gingivalis and H.pylori. In doing so, we shed light on the mechanism by which H. pylori presence in the oral cavity increases the severity or progression of periodontitis.

Helicobacter pylori in the Oral Cavity: Current Evidence and Potential Survival Strategies

Helicobacter pylori (H. pylori) is transmitted primarily through the oral–oral route and fecal–oral route. The oral cavity had therefore been hypothesized as an extragastric reservoir of H. pylori, owing to the presence of H. pylori DNA and particular antigens in distinct niches of the oral cavity. This bacterium in the oral cavity may contribute to the progression of periodontitis and is associated with a variety of oral diseases, gastric eradication failure, and reinfection. However, the conditions in the oral cavity do not appear to be ideal for H. pylori survival, and little is known about its biological function in the oral cavity. It is critical to clarify the survival strategies of H. pylori to better comprehend the role and function of this bacterium in the oral cavity. In this review, we attempt to analyze the evidence indicating the existence of living oral H. pylori, as well as potential survival strategies, including the formation of a favorable microenvironment, the interaction between H. pylori and oral microorganisms, and the transition to a non-growing state. Further research on oral H. pylori is necessary to develop improved therapies for the prevention and treatment of H. pylori infection.

A Cross-Sectional Study on Molecular Detection of Helicobacter pylori cytotoxin-associated gene A and 16SrRNA Gene from Gastric Biopsy Specimens

Introduction:

The aim of the study is relative proportion of cytotoxin-associated gene A (cagA) virulence marker in Helicobacter pylori isolates and gastric biopsy samples by polymerase chain reaction (PCR).

Methods:

This cross-sectional study was conducted at a tertiary care hospital setting. Gastric biopsy tissues from 200 patients, suffering from upper gastrointestinal tract disorders, were examined for H. pylori infection using methods, such as hematoxylin and eosin (H and E) staining, 16S rRNA (Ribosomal ribonucleic acid), and cagA gene PCR. Chi-square and kappa statistics were used to find the association and agreement between the tests, respectively; P ≤ 0.05 was considered statistically significant. Screening tests' accuracy was calculated in terms of sensitivity and specificity along with positive and negative predictive values.

Results:

Out of 200 patients, H. pylori was detected in 14.5%, 48.5%, and 31% patients by H and E staining, 16S rRNA, and cagA PCR, respectively. Sensitivity and specificity of cagA PCR as compared to H and E staining were 89.6% and 78.9%, respectively.

Conclusions:

CagA detection directly from biopsy specimen by PCR can potentially and rapidly determine the patient's status, especially when at a higher risk of peptic ulcer.

Presence of non-oral bacteria in the oral cavity

A homeostatic balance exists between the resident microbiota in the oral cavity and the host. Perturbations of the oral microbiota under particular conditions can contribute to the growth of non-oral pathogens that are hard to kill because of their higher resistance to antimicrobials, raising the probability of treatment failure and reinfection. The presence of these bacteria in the oral cavity has been proven to be associated with several oral diseases such as periodontitis, caries, and gingivitis, and systemic diseases of importance in clinical medicine such as cystic fibrosis, HIV, and rheumatoid arthritis. However, it is still controversial whether these species are merely transient members or unique to the oral cavity. Mutualistic and antagonistic interactions between the oral microbiota and non-oral pathogens can also occur, though the mechanisms used by these bacteria are not clear. Therefore, this review presents an overview of the current knowledge about the presence of non-oral bacteria in the oral cavity, their relationship with systemic and oral diseases, and their interactions with oral bacteria.

Periodontal disease and Helicobacter pylori infection in oral cavity: a meta-analysis of 2727 participants mainly based on Asian studies

OBJECTIVES

To assess the association between periodontal disease and Helicobacter pylori (H. pylori) infection in oral cavity.

MATERIALS AND METHODS

We searched PubMed, Embase, Web of Science, Cochrane library, Gray literature, and clinicaltrials.gov for eligible studies up to September 25, 2019. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. The random-effects model was used with the software STATA 13.0. The Newcastle-Ottawa-Scale was used for quality evaluation.

RESULTS

Twelve observational studies (eight from Asia, one from Europe, and three from the South America) involving 2727 participants were included in the meta-analysis. The overall pooled results showed that H. pylori infection in oral cavity was associated with periodontal disease (OR 2.53, 95% CI 1.86-3.44, P < 0.05). No significant heterogeneity among the articles was observed (I² = 44.3%, P < 0.05). The sensitivity analysis indicated that the result of our meta-analysis was generally stable. The Begg test and the Egger test both showed no publication bias was observed (P = 0.45 and P = 0.18 respectively).

CONCLUSIONS

Based on current available evidence, it seemed there was a correlation between oral H. pylori infection and the occurrence of periodontal disease. However, since most of the data comes from Asia, more large-scale investigations with high quality from all over the world are needed to confirm the association.

CLINICAL RELEVANCE

H. pylori infection in oral may have a positive association with the prevalence of periodontal disease mainly in Asian populations.

Helicobacter pylori was not detected in oral squamous cell carcinomas from cohorts of Norwegian and Nepalese patients

Helicobacter pylori (HP) infection is an established causative agent for gastric cancer. Although the oral cavity is a part of the gastrointestinal system, the presence and possible causative role of HP in oral squamous cell carcinoma (OSCC) is a subject of controversy. Therefore, the current study aimed to investigate HP infection in two cohorts of OSCC patients with different demographic characteristics, lifestyles and habitual risk factors. A total of 242 formalin-fixed paraffin-embedded OSCC specimens from two different patient cohorts (Norway, n = 171 and Nepal, n = 71) were used to examine HP using immunohistochemistry (IHC) and quantitative polymerase chain reaction (qPCR). Two different HP specific genes (23S rRNA and ureA) were used for TaqMan-based qPCR, and for subsequent verification using HP specific RIDAGENE HP kit and SYBR Green based qPCR. All of the OSCC specimens from both cohorts were found to be negative for HP infection with IHC and qPCR, although the positive control specimens tested positive. Our findings suggest that HP is absent in the examined OSCC cohorts, irrespective of race, lifestyle and habitual risk factors. This indicates that, in contrast to gastric cancer, HP is an unlikely contributing factor for OSCC pathogenesis.

Influence of N-acylhomoserine lactonase silver nanoparticles on the quorum sensing system of Helicobacter pylori: A potential strategy to combat biofilm formation

The treatment of Helicobacter pylori usually fails due to their ability to form biofilms and resistance to antibiotics. This might potentially lead to gastric carcinoma and mucosa-associated lymphoid tissue lymphoma. In the present study, we elucidate the potential role of N-acylhomoserine lactonase stabilized silver nanoparticles (AiiA-AgNPs) in treating biofilms produced by H. pylori. AiiA-AgNPs inhibited quorum sensing (QS) by degradation of QS molecules, thereby reducing biofilm formation, urease production, and altering cell surface hydrophobicity of H. pylori. AiiA-AgNPs showed no cytotoxic effects on RAW 264.7 macrophages at the effective concentration (1-5 µM) of antibiofilm activity. In addition, AiiA-AgNP in high concentration (80-100 µM) exhibited cytotoxicity against HCT-15 carcinoma cells, depicting its therapeutic role in treating cancer.

The association between chronic periodontitis and oral Helicobacter pylori: A meta-analysis

BACKGROUND

Epidemiological studies have shown that gastrointestinal Helicobacter pylori (H. pylori) infection is the main cause of chronic gastritis, but the relation between oral H. pylori and chronic periodontitis (CP) remains uncertain. A meta-analysis of published papers was performed to elucidate the correlation between oral H. pylori and CP.

METHOD

To perform this meta-analysis, we searched papers published from 2000 to 2018 on PubMed, OVID, Springer Link, Chinese National Knowledge Infrastructure (CNKI) and Chinese Biology Medicine search engines. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) for the correlation between H. pylori and CP were estimated. Heterogeneity, publication bias and subgroup analyses were also conducted.

RESULTS

A total of 918 papers on oral H. pylori and CP were collected, and 11 papers were in accordance with the inclusion criteria. Oral H. pylori was suggested to be correlated with CP. The results indicated that a H. pylori-positive state significantly increased the risk of CP 3.42 times (OR = 3.42; 95% CI = 2.71-4.31). A diagnostic test using polymerase chain reaction (PCR) showed a higher prevalence of H. pylori (OR = 3.70; 95% CI = 2.66-5.14) than did that using the rapid urease test (RUT) (OR = 3.13; 95% CI = 2.26-4.34).

CONCLUSIONS

This paper demonstrated that CP was potentially correlated with oral H. pylori in adults and that oral H. pylori may be a possible risk factor for CP.

Helicobacter pylori inhibited cell proliferation in human periodontal ligament fibroblasts through the Cdc25C/CDK1/cyclinB1 signaling cascade

Purpose

Several studies have shown that the oral cavity is a secondary location for Helicobacter pylori colonization and that H. pylori is associated with the severity of periodontitis. This study investigated whether H. pylori had an effect on the periodontium. We established an invasion model of a standard strain of H. pylori in human periodontal ligament fibroblasts (hPDLFs), and evaluated the effects of H. pylori on cell proliferation and cell cycle progression.

Methods

Different concentrations of H. pylori were used to infect hPDLFs, with 6 hours of co-culture. The multiplicity of infection in the low- and high-concentration groups was 10:1 and 100:1, respectively. The Cell Counting Kit-8 method and Ki-67 immunofluorescence were used to detect cell proliferation. Flow cytometry, quantitative real-time polymerase chain reaction, and western blots were used to detect cell cycle progression. In the high-concentration group, the invasion of H. pylori was observed by transmission electron microscopy.

Results

It was found that H. pylori invaded the fibroblasts, with cytoplasmic localization. Analyses of cell proliferation and flow cytometry showed that H. pylori inhibited the proliferation of periodontal fibroblasts by causing G2 phase arrest. The inhibition of proliferation and G2 phase arrest were more obvious in the high-concentration group. In the low-concentration group, the G2 phase regulatory factors cyclin dependent kinase 1 (CDK1) and cell division cycle 25C (Cdc25C) were upregulated, while cyclin B1 was inhibited. However, in the high-concentration group, cyclin B1 was upregulated and CDK1 was inhibited. Furthermore, the deactivated states of tyrosine phosphorylation of CDK1 (CDK1-Y15) and serine phosphorylation of Cdc25C (Cdc25C-S216) were upregulated after H. pylori infection.

Conclusions

In our model, H. pylori inhibited the proliferation of hPDLFs and exerted an invasive effect, causing G2 phase arrest via the Cdc25C/CDK1/cyclin B1 signaling cascade. Its inhibitory effect on proliferation was stronger in the high-concentration group.

A meta-analysis of the association between the presence of Helicobacter pylori and periodontal diseases

BACKGROUND

The objective of this meta-analysis is to evaluate the association between the presence of Helicobacter pylori (H pylori) and periodontal disease (PD).

METHODS

PubMed and EMBASE databases were searched to identify eligible articles published from inception up to April 2018. Further articles were retrieved through a manual search of recent reviews. Cross-sectional studies, case-control studies and cohort studies reporting the association between H pylori and PD were included. The pooled odds ratio (OR) and their 95% confidence interval (CI) were calculated.

RESULTS

Four case-control studies and nine cross-sectional studies were included. A total of 6800 patients were included in this review. The odds for oral H pylori positivity was 2.31 times (95% CI: 1.99-2.68) greater than those without H pylori. Subgroup analyses involving different study locations, designs, and types of study population showed the similar results. The pooled OR for the gastric disease patients was the largest (3.50, 95% CI: 2.22-5.53, five articles). Stomach H pylori was also significantly associated with PD, with OR 2.90 (95% CI: 1.37-6.14, two articles).

CONCLUSIONS

This meta-analysis supports an association between H pylori and PD. More well-designed studies, especially prospective cohort studies are necessary to confirm these results.

Association between Helicobacter pylori gastritis and dental diseases: A cross-sectional, hospital-based study in Eastern Saudi Arabia

BACKGROUND

There is inconsistent evidence about the association between Helicobacter pylori (H. pylori) and dental diseases with possible effect of environmental factors. The aims of the study were to assess (1) the association between gastric and oral H. pylori colonization and (2) the association between oral colonization of H. pylori and dental diseases.

METHODS

A cross-sectional study was conducted in King Fahad University hospital in Khobar, Eastern Saudi Arabia in 2017. Patients admitted to the Endoscopy Unit were recruited and clinically examined for plaque, decayed teeth (D), filled teeth (F), missing teeth (M), periodontal pocket depth (PPD), attachment loss (AL), and gingival bleeding in addition to assessing their age, gender, education, tooth brushing, flossing, and tobacco use with a questionnaire. Pooled dental plaque samples were collected and analyzed using nested polymerase chain reaction PCR to detect oral H. pylori. Gastroscopy was used to extract biopsies to assess gastritis and the presence of gastric H. pylori using Giemsa stain. Regression analysis was used to assess differences between patients with and without gastritis, oral H. pylori and gastric H. pylori in the percentage of sites with gingival bleeding, PPD, CAL, D, M, and F with adjustment for confounders.

RESULTS

One hundred twenty patients were included. Most of them brushed daily (82.6%) and had university education (45.7%). Of these, 34.2% had gastric H. pylori and 5% had oral H. pylori. No significant association was observed between the percentage of sites with gingival bleeding, mean PPD, AL, F, and either gastritis, the presence of oral or gastric H. pylori. Patients with gastritis had significantly higher number of D and M than patients without gastritis (P = 0.03).

CONCLUSIONS

In this study, the presence of gastric and oral H. pylori in patients with good oral hygiene and moderate socioeconomic status is not significantly associated with periodontal diseases. Patients with gastritis tend to have a higher number of decayed and missing teeth.

Review: Impact of Helicobacter pylori on Alzheimer's disease: What do we know so far?

BACKGROUND

Helicobacter pylori has changed radically gastroenterologic world, offering a new concept in patients' management. Over time, more medical data gave rise to diverse distant, extragastric manifestations and interactions of the "new" discovered bacterium. Special interest appeared within the field of neurodegenerative diseases and particularly Alzheimer's disease, as the latter and Helicobacter pylori infection are associated with a large public health burden and Alzheimer's disease ranks as the leading cause of disability. However, the relationship between Helicobacter pylori infection and Alzheimer's disease remains uncertain.

METHODS

We performed a narrative review regarding a possible connection between Helicobacter pylori and Alzheimer's disease. All accessible relevant (pre)clinical studies written in English were included. Both affected pathologies were briefly analyzed, and relevant studies are discussed, trying to focus on the possible pathogenetic role of this bacterium in Alzheimer's disease.

RESULTS

Data stemming from both epidemiologic studies and animal experiments seem to be rather encouraging, tending to confirm the hypothesis that Helicobacter pylori infection might influence the course of Alzheimer's disease pleiotropically. Possible main mechanisms may include the bacterium's access to the brain via the oral-nasal-olfactory pathway or by circulating monocytes (infected with Helicobacter pylori due to defective autophagy) through disrupted blood-brain barrier, thereby possibly triggering neurodegeneration.

CONCLUSIONS

Current data suggest that Helicobacter pylori infection might influence the pathophysiology of Alzheimer's disease. However, further large-scale randomized controlled trials are mandatory to clarify a possible favorable effect of Helicobacter pylori eradication on Alzheimer's disease pathophysiology, before the recommendation of short-term and cost-effective therapeutic regimens against Helicobacter pylori-related Alzheimer's disease.

Detection and genotyping of Helicobacter pylori in saliva versus stool samples from asymptomatic individuals in Northeastern Thailand reveals intra-host tissue-specific H. pylori subtypes

BACKGROUND

Two-thirds of the world's population is thought to be infected by Helicobacter pylori. Although most people infected with H. pylori are asymptomatic, this pathogen is associated with several gastric pathologies including cancer. The risk factors for colonization are still unclear and the genetic diversity within individual hosts has never been clearly investigated.

RESULT

This study determined the prevalence of, and explored risk factors for, H. pylori infection directly from paired saliva (n = 110) and stool (n = 110) samples from asymptomatic persons in Northeast Thailand. Samples were subjected to indirect immunofluorescence assay (IFA), 16S rRNA-based real-time PCR and vacA-based semi-nested PCR. Partial vacA gene sequences of H. pylori were compared between saliva and stool samples. The overall prevalence of H. pylori infection in our asymptomatic study population was 64%. Age, gender, occupation and frequency of brushing teeth were not found to be associated with H. pylori colonization. The vacA gene was successfully sequenced from both saliva and stool samples of 12 individuals. For seven of these individuals, saliva and stool sequences fell into different clusters on a phylogenetic tree, indicating intra-host genetic variation of H. pylori.

CONCLUSION

This study reports a high prevalence of H. pylori infection in asymptomatic persons in this region of Thailand and demonstrates that genotypes (vacA gene sequences) of H. pylori may differ between the oral cavity and intestinal tract.

The oral cavity microbiota: between health, oral disease, and cancers of the aerodigestive tract

Many studies show that the human microbiome plays a critical role in the chronic pathologies of obesity, inflammatory bowel diseases, and diabetes. More recently, the interaction between cancer and the microbiome has been highlighted. Most studies have focused on the gut microbiota because it represents the most extensive bacterial community, and the body of evidence correlating it with gut syndromes is increasing. However, in the strict sense, the gastrointestinal (GI) tract begins in the oral cavity, and special attention should be paid to the specific flora of this cavity. This study reviewed the current knowledge about the various microbial ecosystems of the upper part of the GI tract and discussed their potential link to carcinogenesis. The overall composition of the microbial communities, as well as the presence or absence of "key species", in relation to carcinogenesis is addressed. Alterations in the oral microbiota can potentially be used to predict the risk of cancer. Molecular advances and the further monitoring of the microbiota will increase our understanding of the role of the microbiota in carcinogenesis and open new perspectives for future therapeutic and prophylactic modalities.

Clinical Comparative Study of the Effects of Helicobacter Pylori Colonization on Oral Health in Children

OBJECTIVE

To isolate Helicobacter pylori (HP) from the dental plaque of a selected group of children and to compare the oral and salivary findings of patients with those of a healthy control group.

METHODS

A total of 70 children aged 5-15 years were included in this study. An intraoral examination was performed for each patient, and dental plaque and saliva specimens were collected for analysis. Oral health conditions, nutritional habits, tooth brushing frequency, saliva pH levels, flow velocity, and buffering capacities were noted. The Kruskal-Wallis test was used for comparison of the DMFT and dft index. The significance level was set at p=0.05.

RESULTS

The prevalence of HP in dental plaque was higher in study group than controls (p<0.05). There were no significant differences between groups with respect to DMFT and dft scores, nutritional habits, tooth brushing frequency, saliva pH level or flow velocity (p>0.05). Meanwhile, the buffering capacity of saliva was lower in HP gastritis patients (p<0.05).

CONCLUSION

There was a high prevalence of HP in dental plaque; thus, the oral cavity may be an important reservoir for HP. Good oral hygiene could be a positive contributor to the treatment of gastritis.

Critical Role of Antimicrobial Peptide Cathelicidin for Controlling Helicobacter pylori Survival and Infection

The antimicrobial peptide cathelicidin is critical for protection against different kinds of microbial infection. This study sought to elucidate the protective action of cathelicidin against Helicobacter pylori infection and its associated gastritis. Exogenous cathelicidin was found to inhibit H. pylori growth, destroy the bacteria biofilm, and induce morphological alterations in H. pylori membrane. Additionally, knockdown of endogenous cathelicidin in human gastric epithelial HFE-145 cells markedly increased the intracellular survival of H. pylori. Consistently, cathelicidin knockout mice exhibited stronger H. pylori colonization, higher expression of proinflammatory cytokines IL-6, IL-1β, and ICAM1, and lower expression of the anti-inflammatory cytokine IL-10 in the gastric mucosa upon H. pylori infection. In wild-type mice, H. pylori infection also stimulated gastric epithelium-derived cathelicidin production. Importantly, pretreatment with bioengineered Lactococcus lactis that actively secretes cathelicidin significantly increased mucosal cathelicidin levels and reduced H. pylori infection and the associated inflammation. Moreover, cathelicidin strengthened the barrier function of gastric mucosa by stimulating mucus synthesis. Collectively, these findings indicate that cathelicidin plays a significant role as a potential natural antibiotic for H. pylori clearance and a therapeutic agent for chronic gastritis.

Helicobacter pylori and its reservoirs: A correlation with the gastric infection

Helicobacter pylori (H. pylori) has long been found to cause gastric diseases such as gastritis, gastric ulcers and gastric cancer. The transmission medium of this bacterium has yet to be determined, though several studies have speculated that the oral cavity is a reservoir for H. pylori. Others have also reported that the oral cavity may be a source of both transmission and gastric reinfection; however, such results are controversial. We reviewed the literature and selected studies that report an association among H. pylori detections in the oral cavity (dental plaque, saliva, tongue, tonsil tissue, root canals, oral mucosa) in humans and in animals, as well as in the human stomach. The oral cavity may be considered the main reservoir for H. pylori. There are a correlations between H. pylori infection in the oral cavity and periodontal disease, oral tissue inflammation, H. pylori transmission, and gastric reinfection. We believe that the mouth is a reservoir and that it plays a crucial role in both H. pylori transmission and gastric infection.

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.

An inverse association of Helicobacter pylori infection with oral squamous cell carcinoma

BACKGROUND

Few studies have focused on the relationship between Helicobacter pylori (H. pylori) infection and oral diseases. In this study, we explored the correlation between H. pylori infection and oral squamous cell carcinoma (OSCC).

METHODS

A total of 68 patients with OSCC and 104 age- and sex- matched healthy control subjects were retrospectively enrolled in this study. The H. pylori immunoglobin (Ig) G antibodies in serum were detected by enzyme-linked immunosorbent assay (ELISA) method to assess the status of H. pylori infection of our study sample. Polymerase chain reaction (PCR) was also employed using H. pylori genus-specific 16S rRNA primers in fasting blood, and OSCC specimens were analyzed by histochemical stain of each enrolled subject. The strength of correlation between H. pylori and the development of OSCC was estimated by Spearman's correlation coefficient.

RESULTS

According to the three methods for detecting prevalence of H. pylori infection in the patients with OSCC, it was statistically lower than that in the healthy controls (35.3% vs. 54.8%, P = 0.012). An inverse correlation was observed between H. pylori infection and OSCC development (Spearman's correlation coefficient = -0.191, P = 0.012). In stratification analysis, we also found a statistical association between H. pylori infection and OSCC in the subpopulation with age ≥ 60 years (P = 0.037).

CONCLUSION

Our findings suggested that H. pylori infection may be negatively related to OSCC. A reverse association of H. pylori infection with OSCC risk in the subpopulation with age ≥ 60 years was also found.

Association of Salivary Helicobacter pylori Infection with Oral Diseases: a Cross-sectional Study in a Chinese Population

OBJECTIVE

The aim of this study was to detect the prevalence of oral H.pylori among adults and to investigate the correlation between H.pylori infection and common oral diseases.

STUDY DESIGN

A cross-sectional study was performed among adults Chinese who took their annual oral healthy examination at The First Affiliated Hospital, Zhejiang University School of Medicine, China.

RESULTS

The study included 1050 subjects in total and oral H.pylori infection occurred in 60.29% of the subjects. The prevalence rates of oral H.pylori in patients with periodontal diseases (63.42%) and caries (66.91%) were significantly increased than those without oral diseases (54.07%), respectively (P < 0.05), while the difference between subjects with recurrent aphthous stomatitis and controls was not significant. In addition, the differences of positive rates of H.pylori with or without history of gastric ulcer were statistically significant (69.47% vs 58.26%, P<0.05). Presenting with periodontal diseases (OR 1.473;95% CI 1.021 to 2.124), caries (OR 1.717; 1.127 to 2.618), and having history of gastric ulcer (OR 1.631; 1.164 to 2.285) increased the risk of H.pylori infection.

CONCLUSIONS

Oral H.pylori infection is common in adult Chinese, which is significantly associated with oral diseases including periodontal diseases and caries.

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.

Biofilms and Helicobacter pylori: Dissemination and persistence within the environment and host

The presence of viable Helicobacter pylori (H. pylori) in the environment is considered to contribute to the levels of H. pylori found in the human population, which also aids to increase its genetic variability and its environmental adaptability and persistence. H. pylori form biofilms both within the in vitro and in vivo environment. This represents an important attribute that assists the survival of this bacterium within environments that are both hostile and adverse to proliferation. It is the aim of this paper to review the ability of H. pylori to form biofilms in vivo and in vitro and to address the inherent mechanisms considered to significantly enhance its persistence within the host and in external environments. Furthermore, the dissemination of H. pylori in the external environment and within the human body and its impact upon infection control will be discussed.

Helicobacter pylori infection - recent developments in diagnosis

Considering the recommended indications for Helicobacter pylori (H. pylori) eradication therapy and the broad spectrum of available diagnostic methods, a reliable diagnosis is mandatory both before and after eradication therapy. Only highly accurate tests should be used in clinical practice, and the sensitivity and specificity of an adequate test should exceed 90%. The choice of tests should take into account clinical circumstances, the likelihood ratio of positive and negative tests, the cost-effectiveness of the testing strategy and the availability of the tests. This review concerns some of the most recent developments in diagnostic methods of H. pylori infection, namely the contribution of novel endoscopic evaluation methodologies for the diagnosis of H. pylori infection, such as magnifying endoscopy techniques and chromoendoscopy. In addition, the diagnostic contribution of histology and the urea breath test was explored recently in specific clinical settings and patient groups. Recent studies recommend enhancing the number of biopsy fragments for the rapid urease test. Bacterial culture from the gastric biopsy is the gold standard technique, and is recommended for antibiotic susceptibility test. Serology is used for initial screening and the stool antigen test is particularly used when the urea breath test is not available, while molecular methods have gained attention mostly for detecting antibiotic resistance.

Role of dental plaque, saliva and periodontal disease in Helicobacter pylori infection

Helicobacter pylori (H. pylori) infection is one of the most common bacterial infections in humans. Although H. pylori may be detected in the stomach of approximately half of the world's population, the mechanisms of transmission of the microorganism from individual to individual are not yet clear. Transmission of H. pylori could occur through iatrogenic, fecal-oral, and oral-oral routes, and through food and water. The microorganism may be transmitted orally and has been detected in dental plaque and saliva. However, the role of the oral cavity in the transmission and recurrence of H. pylori infection has been the subject of debate. A large number of studies investigating the role of oral hygiene and periodontal disease in H. pylori infection have varied significantly in terms of their methodology and sample population, resulting in a wide variation in the reported results. Nevertheless, recent studies have not only shown that the microorganism can be detected fairly consistently from the oral cavity but also demonstrated that the chances of recurrence of H. pylori infection is more likely among patients who harbor the organism in the oral cavity. Furthermore, initial results from clinical trials have shown that H. pylori-positive dyspeptic patients may benefit from periodontal therapy. This paper attempts to review the current body of evidence regarding the role of dental plaque, saliva, and periodontal disease in H. pylori infection.

A Comparison in Prevalence of Helicobacter pylori in the Gingival Crevicular Fluid from Subjects with Periodontitis and Healthy Individuals using Polymerase Chain Reaction

Background and aims. The high prevalence of Helicobacter pylori among the microorganisms isolated from the oral environment brings up the question of whether oral cavity acts as a reservoir for this bacterium. The aim of the present study was to determine and compare the prevalence of H. pylori in gingival crevicular fluid (GCF) of patients with chronic periodontitis (CP) as an infectious disease and healthy subjects using polymerase chain reaction (PCR).

Materials and methods. Periodontal examination was performed for all participants. Two sterilized paper points were inserted to the maximum depth of the periodontal pockets of selected teeth. The presence of H. pylori was determined by PCR. In the CP group, the severity of disease was defined as moderate or severe. Further, the frequency of Helicobacter pylori in GCF of each category, and the association between the presence of Helicobacter pylori in GCF and periodontitis were determined.

Results. There was no statistically significant association between CP and the presence of H. pylori in the GCF (P = 0.62), there was no significant correlation between the presence of H. pylori in the GCF and gender of the subjects (P = 0.28 in CP group and P = 0.25 in control group), and there was no significant correlation between the presence of H. pylori in the GCF and severity of periodontitis (P = 0.20).

Conclusion. Oral cavity acts as a reservoir for H. pylori; however, the results do not show that H. pylori is involved in periodontal disease.

Effect of periodontal therapy on prevention of gastric Helicobacter pylori recurrence: a systematic review and meta-analysis

AIM

The aim of this review is to assess the effect of dental plaque control and periodontal therapy on prevention of gastric Helicobacter pylori (H. pylori) recurrence.

MATERIALS AND METHODS

We conducted searches of electronic databases, and included controlled trials comparing periodontal treatment and eradication therapy of H. pylori with eradication therapy alone for prevention of recurrence of gastric H. pylori. We used the absence of recurrence of gastric H. pylori after the first 3 months as an outcome measure to determine relative risk of persistence of gastric H. pylori. We estimated the degree of heterogeneity among trial results using Q and I(2) statistics.

RESULTS

Three trials including 298 patients were eligible according to our inclusion criteria. As significant heterogeneity was indicated by the Q statistics (p = 0.04) and I(2) (69%), we used a random-effects model to combine the data. Compared with eradication therapy alone, the adjunction of periodontal therapy significantly reduced the relative risk of persistence of gastric H. pylori by 63% (0.37 [95% CI 0.21-0.64], p = 0.0004) in patients with gastric diseases.

CONCLUSIONS

The adjunction of periodontal treatment to eradication therapy appears to reduce gastric H. pylori recurrence compared with eradication therapy alone among patients with gastric diseases associated with H. pylori. The results of this meta-analysis should be taken with caution because of the limitations in the primary data.

Halitosis and Helicobacter pylori infection

There is disagreement about a possible relationship between Helicobacter pylori (H. pylori) infection and objective halitosis, as established by volatile sulfur compounds (VSCs) in the breath. Many studies related to H. pylori used self-reported halitosis, a subjective and unreliable method to detect halitosis. In this study a possible relation between H. pylori and halitosis was evaluated, using an objective method (gas chromatography, GC) to detect the VSCs, responsible for the halitosis. The levels of the VSCs hydrogen sulfide (H(2)S), methyl mercaptan (MM) and dimethyl sulfide (DMS) were measured in mouth breath and in stomach air of 11 H. pylori positive patients and of 38 H. pylori negative patients, all with gastric pathology. Halitosis was also established by organoleptic scoring (OLS) of mouth-breath. The levels of H(2)S, MM and DMS in the mouth-breath and stomach air of the H. pylori positive patients did not differ significantly from those of the H. pylori negative patients. OLS of the mouth-breath resulted in 9 patients with halitosis, 1 out of the H. pylori positive group and 8 out of the H. pylori negative group, which is not statistically different. The concentrations of the VSCs in stomach air were in nearly all cases below the thresholds of objectionability of the various VSCs, indicating that halitosis does not originate in the stomach. The patients with gastric pathology were also compared with control patients without gastric pathology and with normal volunteers. No significant differences in VSCs in mouth breath were observed between these groups. Thus, in this study no association between halitosis and H. pylori infection was found. Halitosis, as established by GC and OLS, nearly always originates within the oral cavity and seldom or never within the stomach.

Impact of periodontal therapy on the subgingival microbiota of severe periodontitis: comparison between good responders and individuals with refractory periodontitis using the human oral microbe identification microarray

BACKGROUND

This study compares the changes to the subgingival microbiota of individuals with "refractory" periodontitis (RP) or treatable periodontitis (good responders [GR]) before and after periodontal therapy by using the Human Oral Microbe Identification Microarray (HOMIM) analysis.

METHODS

Individuals with chronic periodontitis were classified as RP (n = 17) based on mean attachment loss (AL) and/or >3 sites with AL ≥2.5 mm after scaling and root planing, surgery, and systemically administered amoxicillin and metronidazole or as GR (n = 30) based on mean attachment gain and no sites with AL ≥2.5 mm after treatment. Subgingival plaque samples were taken at baseline and 15 months after treatment and analyzed for the presence of 300 species by HOMIM analysis. Significant differences in taxa before and post-therapy were sought using the Wilcoxon test.

RESULTS

The majority of species evaluated decreased in prevalence in both groups after treatment; however, only a small subset of organisms was significantly affected. Species that increased or persisted in high frequency in RP but were significantly reduced in GR included Bacteroidetes sp., Porphyromonas endodontalis, Porphyromonas gingivalis, Prevotella spp., Tannerella forsythia, Dialister spp., Selenomonas spp., Catonella morbi, Eubacterium spp., Filifactor alocis, Parvimonas micra, Peptostreptococcus sp. OT113, Fusobacterium sp. OT203, Pseudoramibacter alactolyticus, Streptococcus intermedius or Streptococcus constellatus, and Shuttlesworthia satelles. In contrast, Capnocytophaga sputigena, Cardiobacterium hominis, Gemella haemolysans, Haemophilus parainfluenzae, Kingella oralis, Lautropia mirabilis, Neisseria elongata, Rothia dentocariosa, Streptococcus australis, and Veillonella spp. were more associated with therapeutic success.

CONCLUSION

Persistence of putative and novel periodontal pathogens, as well as low prevalence of beneficial species was associated with chronic refractory periodontitis.

Association of red complex, A. actinomycetemcomitans and non-oral bacteria with periodontal diseases

OBJECTIVE

Pathogens related to systemic infections have been detected in the periodontal microbiota. The relationship amongst these pathogens, periodontal bacteria and periodontal clinical status is poorly understood. This study evaluated the association amongst red complex, A. actinomycetemcomitans (A.a) and non-oral pathogenic bacteria in subjects with good periodontal health (PH), gingivitis (G), chronic (CP) and aggressive (AP) periodontitis.

METHODS

Subgingival biofilm samples were obtained from 51 PH, 42 G, 219 CP and 90 AP subjects. The presence and levels of A.a, red complex (Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola), Acinetobacter baumannii, Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa, and Staphylococcus aureus were determined by DNA probes and DNA-DNA hybridization technique.

RESULTS

CP and AP subjects presented significantly higher prevalence and levels of A.a, red complex and A. baumannii than G and PH individuals (p<0.01), whereas S. aureus was detected in lower frequency and counts in AP as compared to the other groups (p<0.001). The predictor variables age, prevalence of red complex, and the presence of A. baumannii and P. aeruginosa were strongly associated with the frequency of sites with PD and CAL ≥5 mm. Increasing age (OR 1.08), high frequency of red complex (OR 6.10), and the presence of A.a with P. aeruginosa (OR 1.90) were associated with periodontal disease (p<0.001). Subjects harbouring a high prevalence of A.a, A. baumannii, and red complex with P. aeruginosa were more likely to have AP than CP (p<0.001).

CONCLUSION

Putative periodontal pathogens and non-oral bacteria alone or in association were strongly associated with periodontitis.

The effectiveness of systemic eradication therapy against oral Helicobacter pylori

BACKGROUND

Helicobacter pylori infection is associated with numerous gastroduodenal diseases. The oral cavity could be a potential extragastric reservoir for H. pylori, and oral H. pylori might cause gastric reinfection after the eradication therapy. The aim of the study was to evaluate the presence of H. pylori in oral cavity of patients with gastric H. pylori infection and to examine the effectiveness of the eradication therapy against H. pylori in stomach and in the oral cavity.

METHODS

Fifty-six patients with chronic periodontitis and gastric H. pylori were enrolled in the study. Gastric H. pylori infection was determined using (13) C-urea breath test before and 3 months after eradication therapy. The presence of the oral H. pylori was assessed using polymerase chain reaction before and 3 months after eradication therapy. The 1-week eradication therapy consisted of amoxycilin 1 g, clarithromycin 500 mg, and proton pump inhibitor 20 mg twice a day.

RESULTS

Of 56 subjects with gastric infection, 23 (41.1%) harbored H. pylori in the oral cavity. Eradication rate in stomach was 78.3%, whereas in the oral cavity, H. pylori was not detected from any sample after the eradication therapy.

CONCLUSION

Almost half of the patients with gastric H. pylori harbored the bacterium in the oral cavity. After the eradication therapy, H. pylori was not detected in the oral cavity, what suggests high effectiveness of the therapy protocol in the oral cavity, or it is possible that oral H. pylori is of a transient character.

Oxidative stress induced mechanisms in the progression of periodontal diseases and cancer: a common approach to redox homeostasis?

There is documented evidence of significant associations between cancer of the lung, kidney, pancreas, hematological and oral cancers and periodontal diseases of the supporting structures of the teeth. Enhanced lipid peroxidation, raised levels of TBARS and the oxidative stress marker malondealdehyde have been detected in breast cancer with reduced antioxidant capacity, also characteristic of periodontal diseases. Antioxidants could overcome this deficit and attenuate disease progression by down regulating glutathione detoxification/redox buffering system and inhibiting key transcription factors. Periodontal disease may be a critical marker of a susceptible immune system, or initiate cancer risk with a pro-oxidant inflammatory profile.

Transmission pathway of Helicobacter pylori: does food play a role in rural and urban areas?

Helicobacter pylori is a Gram-negative microaerophilic bacterium that has colonized the human gastric mucosa. This infection is very common and affects more than half of the human population. The prevalence is however unbalanced between rural developing areas (more than 80%) and urban developed areas (less than 40%). H. pylori is responsible for several pathologies, such as gastritis, peptic ulcer and gastric cancer but its transmission pathway is still not clear. The risk factors for H. pylori infection include poor social and economic development; poor hygienic practices; absence of hygienic drinking water; and unsanitary prepared food. There is evidence supporting a gastro-oral, oral-oral and faecal-oral transmission, but no predominant mechanism of transmission has been yet identified. Transmission may occur in a vertical mode (e.g. from parents to child) or in a horizontal mode (across individuals or from environmental contamination). In either case, the involvement of water and food cannot be excluded as vehicles or sources of infection. Indirect evidence of presence of H. pylori in water and food, namely the detection of its DNA and survival studies after artificial contamination of food and water has been described. This paper reviews data both favourable and against the role of water and food in the transmission of H. pylori, exploring their role as a potential transmission vehicle for person-to-person and food-chain transmission. The likelihood of the transmission pathway in developing rural and developed urban areas appears to be different. In developed areas, person-to-person transmission within families appears to be dominant, while in the rural developing areas the transmission pathway appears to be more complex. In this later case, the transmission by contaminated food, water, or via intensive contact between infants and non-parental caretakers may have a greater influence than within-family transmission.

Advances in understanding the association of Helicobacter pylori infection with extragastric diseases

Helicobacter pylori (H. pylori) infection is one of the most common human infections worldwide. It is associated with the development of a number of important upper gastrointestinal (GI) diseases such as chronic gastritis, peptic ulcer and gastric malignancy. At present, there is evidence that H. pylori infection probably plays a critical role in the development of some extragastric diseases. However, there is still controversy over such association. In this article, we will give an overview of the recent advances in understanding the association of H. pylori infection with extragastric diseases.

Oral cavity is not a reservoir for Helicobacter pylori in infected patients with functional dyspepsia

INTRODUCTION

Helicobacter pylori infection is very prevalent in Brazil, infecting almost 65% of the population. The aim of this study was to evaluate the presence of this bacterium in the oral cavity of patients with functional dyspepsia (epigastric pain syndrome), establish the main sites of infection in the mouth, and assess the frequency of cagA and vacA genotypes of oral H. pylori.

METHODS

All 43 outpatients with epigastric pain syndrome, who entered the study, were submitted to upper gastrointestinal endoscopy to rule out organic diseases. Helicobacter pylori infection in the stomach was confirmed by a rapid urease test and urea breath tests. Samples of saliva, the tongue dorsum and supragingival dental plaque were collected from the oral cavity of each subject and subgingival dental plaque samples were collected from the patients with periodontitis; H. pylori infection was verified by polymerase chain reaction using primers that amplify the DNA sequence of a species-specific antigen present in all H. pylori strains; primers that amplify a region of urease gene, and primers for cagA and vacA (m1, m2, s1a, s1b, s2) genotyping.

RESULTS

Thirty patients harbored H. pylori in the stomach, but it was not possible to detect H. pylori in any oral samples using P1/P2 and Urease A/B. The genotype cagA was also negative in all samples and vacA genotype could not be characterized (s-m-).

CONCLUSION

The oral cavity may not be a reservoir for H. pylori in patients with epigastric pain syndrome, the bacterium being detected exclusively in the stomach.

Detection of Helicobacter pylori, Enterococcus faecalis, and Pseudomonas aeruginosa in the subgingival biofilm of HIV-infected subjects undergoing HAART with chronic periodontitis

This study compared the frequency of Helicobacter pylori, Enterococcus faecalis, and Pseudomonas aeruginosa in the subgingival microbiota of HIV-seropositive and HIV-seronegative subjects with periodontitis or clinically healthy periodontal tissues. Fifty-four subjects were distributed into two HIV-seropositive groups (chronic periodontitis [HCP = 13] and periodontal health [HH = 10]) and two HIV-seronegative groups (chronic periodontitis [CP = 17] and periodontal health [H = 14]). The detection of bacterial species was carried out by polymerase chain reaction (PCR). CP patients showed significantly more periodontal destruction, inflammation, and supragingival plaque than HCP patients (P < 0.05). All species were detected at a higher prevalence in CP and HCP than H individuals (P < 0.01). In the HIV groups, H. pylori was significantly more prevalent in periodontitis compared to healthy patients (P < 0.01). A higher frequency of E. faecalis and P. aeruginosa was observed in the subgingival biofilm of HH than H subjects (P < 0.01). Moreover, E. faecalis was detected significantly more often in HIV-seropositive compared to HIV-seronegative patients, regardless of periodontal status (P < 0.01). These data indicate that H. pylori is frequently detected in the subgingival microbiota of periodontitis subjects. In contrast, HIV-seropositive patients with either periodontitis or periodontal health present a high prevalence of E. faecalis.

Helicobacter pylori-coccoid forms and biofilm formation

Electron microscopic studies have shown that Helicobacter pylori occurs in three stages: spiral forms, coccoid forms and degenerative forms. The spiral forms are viable, culturable, virulent and can colonize experimental animals and induce inflammation. The coccoid forms may also be viable but are nonculturable, less virulent and are less likely to colonize and induce inflammation in experimental animals than the spiral forms. The degenerative forms are pyknotic, nonculturable, coccoid forms of dead H. pylori. These forms cannot be cultured and the cell membrane has disintegrated but gene material can be detected by PCR in water supplies. There is no substantial evidence for viable H. pylori persisting in water supplies. Epidemiological studies suggest that environmental water is a risk factor for H. pylori infection when compared with tap water, and formation of H. pylori biofilm cannot be excluded. Helicobacter pylori does not seem to take part in biofilm formation in the oral cavity even though the bacterium may be detected.

Detection of Helicobacter pylori DNA in the saliva of patients complaining of halitosis

Helicobacter pylori infection, which causes peptic ulcers and gastric cancer, is considered a possible cause of halitosis. Recently, the oral cavity was identified as a possible H. pylori reservoir, particularly in the presence of periodontal disease, which is a cause of halitosis. The purpose of this study was to evaluate by PCR the prevalence of oral H. pylori in the saliva of subjects complaining of halitosis. Samples were obtained from 326 non-dyspeptic subjects, comprising 251 subjects with actual malodour and 75 subjects without halitosis. DNA was extracted from the samples, and the presence of H. pylori and periodontopathic bacteria including Porphyromonas gingivalis, Treponema denticola and Prevotella intermedia was examined by PCR. H. pylori was detected in 21 (6.4 %) of 326 samples. The methyl mercaptan concentration and periodontal parameters including tooth mobility, periodontal pocket depth (PPD) and occult blood in the saliva were significantly greater in the H. pylori-positive subjects. Each of the periodontopathic bacteria was also detected at a significantly higher frequency in the H. pylori-positive subjects. Among those patients with a PPD of > or =5 mm and a tongue coating score of < or =2, no difference was observed in oral malodour levels between the H. pylori-positive and -negative subjects. However, the presence of occult blood in the saliva and the prevalence of Prevotella intermedia were significantly greater in the H. pylori-positive subjects. H. pylori was detected in 16 (15.7 %) of 102 subjects with periodontitis, suggesting that progression of periodontal pocket and inflammation may favour colonization by this species and that H. pylori infection may be indirectly associated with oral pathological halitosis following periodontitis.