Helicobacter pylori in the oral cavity: high prevalence and great DNA diversity

Transmission routes and patterns of helicobacter pylori

BACKGROUND AND OBJECTIVE

Helicobacter pylori (H. pylori), a gram-negative bacterium that colonizes the stomach, can cause chronic gastritis and peptic ulcers, as well as gastric cancer as a Class I carcinogen. However, the modes of H. pylori transmission are not clear. This review aims to clarify the transmission routes and patterns of H. pylori and identify efficacious prevention measures.

METHODS

Studies of H. pylori transmission were identified using PubMed, the Web of Science, and Cochrane Central; the retrieval deadline was October 2022.

RESULTS

The transmission routes of H. pylori are discussed, focusing on the five primary transmission routes, namely fecal-oral, oral-oral, gastric-oral, anal-oral, and genital-oral. We propose that H. pylori is contracted through multiple transmission routes. Additionally, we summarize the key transmission patterns of H. pylori, including person-to-person and animal-to-human transmission, as well as foodborne and occupational exposure.

CONCLUSION

Fecal-oral appears to be the most common H. pylori transmission routes. Although the oral-oral pathway is also important, the evidence does not support that this route of transmission is universal. The gastric-oral route occurs primarily in children and patients who are prone to vomiting. Meanwhile, the anal-oral and genital-oral routes remain hypothetical. Person-to-person and foodborne infections represent the predominant transmission patterns of H. pylori, whereas strong environmental and occupational limitations are associated with animal-to-human and occupational exposure.

Association of Chronic Periodontitis with Helicobacter pylori Infection in Stomach or Mouth: A Systematic Review and Meta-Analysis

Helicobacter pylori (H. pylori) infection and periodontitis are both inflammatory conditions associated with systemic diseases. Researchers have attempted to investigate the correlation between them. This systematic review and meta-analyses were conducted to investigate the association of H. pylori infection in the stomach and/or in subgingival plaque and gingival crevicular fluid with chronic periodontitis. The protocol was created according to the Preferred Reporting Items for Systematic review and Meta-Analysis Protocols (PRISMA-P) statement. The study was designed according to the Cochrane criteria. A comprehensive literature search was performed in MEDLINE, Scopus, and CENTRAL, combined with hand-searching and assessment of gray literature. The meta-analysis of the included studies was made by the Review Manager (RevMan) 5.4 software. The effect measure of the outcome was odds ratios with 95% confidence intervals. Heterogeneity was assessed by chi-square and I2. Four observational studies involving 818 subjects were included in this meta-analysis. The odds of oral H. pylori presence were higher in patients with chronic periodontitis, compared to healthy controls, with an odds ratio of 1.87 (95% confidence interval 0.85–4.10; p = 0.12). The odds of the presence of H. pylori in the stomach also were higher in patients with chronic periodontitis, with an odds ratio of 1.80 (95% confidence interval 0.82–3.95; p = 0.15). There is no evidence for an association between chronic periodontitis and the prevalence of H. pylori, detected either in subgingival plaque and gingival crevicular fluid or in the stomach.

Quantification of Helicobacter pylori and its oncoproteins in oral cavity. A cross sectional study

OBJECTIVE

To identify Helicobacter pylori (H.pylori) and related oncogenic and virulent proteins (CagA and VacA) in patients with gingivitis, periodontitis, oral cancer and gastric cancer.

METHODS

Subgingival plaque samples were collected from 90 individuals with either gingivitis/ periodontitis (group A, n=30), oral cancer (group B, n=30) and gastric cancer (group C, n=30). H.pylori was identified by real time- polymerase chain reaction (RT-PCR). The virulent organisms were detected by identification of proteins CagA and VacA through Enzyme Linked Immuno Sorbent Assay (ELISA).

RESULTS

We identified the presence of H.pylori in subgingival plaque samples among a large majority (76/90) of our study cohort. The proportions of CagA and VacA identified among H.pylori individuals with periodontal inflammation and oral cancer were lower than those diagnosed with gastric cancer. Furthermore, the relative risk of oral cancer based on the presence of the organism was no different to those with gingivitis/periodontitis.

CONCLUSION

The findings of our study does not indicate significant association between the organism and oral cancer but preludes that the oral cavity could act as a potential niche for H.pylori. The possibility for CagA and VacA proteins to be pathogenic in oral cavity is highly possible and to be researched extensively.

Current Prevalence of Oral Helicobacter pylori among Japanese Adults Determined Using a Nested Polymerase Chain Reaction Assay

In Japan, gastric Helicobacter pylori infection prevalence has markedly decreased with socioeconomic development. We aimed to investigate the prevalence of oral H. pylori in Japanese adults in 2020 by sex, age, sampling site, and medical history. Unstimulated saliva, supragingival biofilm, and tongue coating were obtained from 88 subjects-with no complaints of upper digestive symptoms-attending a dentist's office for dental check-up or disorders. Supragingival biofilm was collected from the upper incisors, lower incisors, upper right molars and lower left molars to analyze the characteristic distribution. Oral H. pylori was detected using nested polymerase chain reaction. Oral H. pylori prevalence did not statistically differ by sex or age. Supragingival biofilm (30.7%) was the most common oral H. pylori niche; it was also detected in 4.5% of saliva and 2.3% of tongue samples. The lower incisor was the most common site among the supragingival biofilm samples, followed by the upper incisors, lower left molars, and upper right molars. Oral H. pylori DNA was frequently detected in patients with a history of gastric H. pylori infection. Oral H. pylori has a characteristic distribution independent of sex and age, suggesting that it is part of the normal microflora in the adult oral cavity.

Periodontal therapy as adjunctive treatment for gastric Helicobacter pylori infection

BACKGROUND

Helicobacter pylori is estimated to affect about half the world's population and is considered as the main cause of chronic gastritis and peptic ulcer disease. Eradication of H. pylori infection accelerates ulcer healing and prevents relapse, reducing incidence of H. pylori-related gastric diseases. Numerous studies have provided evidence that the oral cavity could be a potential reservoir for H. pylori. The presence of oralH. pylori might affect the efficiency of eradication therapy and act as a causal force for its recurrence. Conversely, other investigators have indicated that the colonization and growth of H. pylori differs between the oral cavity and the stomach. Considering the open debate on the topic, it's necessary to clarify whether periodontal therapy is an effective adjunctive treatment for gastric H. pylori infection.

OBJECTIVES

To assess the effects of periodontal therapy plus eradication therapy versus eradication therapy alone for gastric H. pylori infection. The secondary objective is to compare the non-recurrence rate at long-term follow up in different treatment groups.

SEARCH METHODS

We identified randomized controlled trials (RCTs) by searching the Cochrane Central Register of Controlled Trials (CENTRAL) (2015, Issue 8), MEDLINE (1946 to August 2015), EMBASE (1980 to August 2015), and the Chinese Biomedical Database (1978 to August 2015). We also searched both ClinicalTrials.gov and the WHO ICTRP portal in October 2015. We handsearched the reference lists of included studies to identify relevant trials.

SELECTION CRITERIA

RCTs comparing periodontal therapy plus eradication treatment with eradication treatment alone, regardless of language of publication.

DATA COLLECTION AND ANALYSIS

Two reviewers selected the trials that met the inclusion criteria and extracted the details of each study independently. The data were pooled using both fixed-effect and random-effects models and results calculated as odds ratios (OR) with their 95% confidence intervals (CIs) based on an intention-to-treat analysis. However, because there was little difference in the results from these two models, we only reported the results from the fixed-effect model.

MAIN RESULTS

We included seven small RCTs involving 691 participants aged 17 to 78 years in our meta analyses. The primary result showed that periodontal therapy combined with H. pylori eradication treatment increased the eradication rate of gastric H. pylori compared with eradication treatment alone (OR 2.15; 95% CI 1.47 to 3.14; P < 0.0001) in people with H. pylori infection. In addition, periodontal therapy also had benefits on long-term gastric H. pylori eradication. After eradication of H. pylori, the non-recurrence rate of gastric H. pylori infection increased in participants treated with periodontal therapy compared with those who received eradication therapy alone (OR 3.60; 95% CI 2.11 to 6.15; P < 0.00001). According to the GRADE approach, the overall quality of the evidence was 'moderate' for eradication rate of gastric H.pylori and 'low' for non-recurrence rate of gastric H. pylori.

AUTHORS' CONCLUSIONS

Overall, periodontal therapy could increase the efficiency of H. pylori eradication and the non-recurrence rate of gastricH. pylori. In view of the limited number and quality of included studies, it will be necessary to conduct more well-designed, multicenter, and large-scale RCTs to determine the effects of periodontal therapy in eradicating gastric H. pylori and suppressing the recurrence of this bacterium in the stomach.

Periodontal therapy as adjunctive treatment for gastric Helicobacter pylori infection

BACKGROUND

Helicobacter pylori is estimated to affect about half the world's population and is considered as the main cause of chronic gastritis and peptic ulcer disease. Eradication of H. pylori infection accelerates ulcer healing and prevents relapse, reducing incidence of H. pylori-related gastric diseases. Numerous studies have provided evidence that the oral cavity could be a potential reservoir for H. pylori. The presence of oralH. pylori might affect the efficiency of eradication therapy and act as a causal force for its recurrence. Conversely, other investigators have indicated that the colonization and growth of H. pylori differs between the oral cavity and the stomach. Considering the open debate on the topic, it's necessary to clarify whether periodontal therapy is an effective adjunctive treatment for gastric H. pylori infection.

OBJECTIVES

To assess the effects of periodontal therapy plus eradication therapy versus eradication therapy alone for gastric H. pylori infection. The secondary objective is to compare the non-recurrence rate at long-term follow up in different treatment groups.

SEARCH METHODS

We identified randomized controlled trials (RCTs) by searching the Cochrane Central Register of Controlled Trials (CENTRAL) (2015, Issue 8), MEDLINE (1946 to August 2015), EMBASE (1980 to August 2015), and the Chinese Biomedical Database (1978 to August 2015). We also searched both ClinicalTrials.gov and the WHO ICTRP portal in October 2015. We handsearched the reference lists of included studies to identify relevant trials.

SELECTION CRITERIA

RCTs comparing periodontal therapy plus eradication treatment with eradication treatment alone, regardless of language of publication.

DATA COLLECTION AND ANALYSIS

Two reviewers selected the trials that met the inclusion criteria and extracted the details of each study independently. The data were pooled using both fixed-effect and random-effects models and results calculated as odds ratios (OR) with their 95% confidence intervals (CIs) based on an intention-to-treat analysis. However, because there was little difference in the results from these two models, we only reported the results from the fixed-effect model.

MAIN RESULTS

We included seven small RCTs involving 691 participants aged 17 to 78 years in our meta analyses. The primary result showed that periodontal therapy combined with H. pylori eradication treatment increased the eradication rate of gastric H. pylori compared with eradication treatment alone (OR 2.15; 95% CI 1.47 to 3.14; P < 0.0001) in people with H. pylori infection. In addition, periodontal therapy also had benefits on long-term gastric H. pylori eradication. After eradication of H. pylori, the non-recurrence rate of gastric H. pylori infection increased in participants treated with periodontal therapy compared with those who received eradication therapy alone (OR 3.60; 95% CI 2.11 to 6.15; P < 0.00001). According to the GRADE approach, the overall quality of the evidence was 'moderate' for eradication rate of gastric H.pylori and 'low' for non-recurrence rate of gastric H. pylori.

AUTHORS' CONCLUSIONS

Overall, periodontal therapy could increase the efficiency of H. pylori eradication and the non-recurrence rate of gastricH. pylori. In view of the limited number and quality of included studies, it will be necessary to conduct more well-designed, multicenter, and large-scale RCTs to determine the effects of periodontal therapy in eradicating gastric H. pylori and suppressing the recurrence of this bacterium in the stomach.

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.

Vacuoles of Candida yeast as a specialized niche for Helicobacter pylori

Helicobacter pylori (H. pylori) are resistant to hostile gastric environments and antibiotic therapy, reflecting the possibility that they are protected by an ecological niche, such as inside the vacuoles of human epithelial and immune cells. Candida yeast may also provide such an alternative niche, as fluorescently labeled H. pylori were observed as fast-moving and viable bacterium-like bodies inside the vacuoles of gastric, oral, vaginal and foodborne Candida yeasts. In addition, H. pylori-specific genes and proteins were detected in samples extracted from these yeasts. The H. pylori present within these yeasts produce peroxiredoxin and thiol peroxidase, providing the ability to detoxify oxygen metabolites formed in immune cells. Furthermore, these bacteria produce urease and VacA, two virulence determinants of H. pylori that influence phago-lysosome fusion and bacterial survival in macrophages. Microscopic observations of H. pylori cells in new generations of yeasts along with amplification of H. pylori-specific genes from consecutive generations indicate that new yeasts can inherit the intracellular H. pylori as part of their vacuolar content. Accordingly, it is proposed that yeast vacuoles serve as a sophisticated niche that protects H. pylori against the environmental stresses and provides essential nutrients, including ergosterol, for its growth and multiplication. This intracellular establishment inside the yeast vacuole likely occurred long ago, leading to the adaptation of H. pylori to persist in phagocytic cells. The presence of these bacteria within yeasts, including foodborne yeasts, along with the vertical transmission of yeasts from mother to neonate, provide explanations for the persistence and propagation of H. pylori in the human population. This Topic Highlight reviews and discusses recent evidence regarding the evolutionary adaptation of H. pylori to thrive in host cell vacuoles.

Oral Cavity as an Extragastric Reservoir of Helicobacter pylori

Background. Several studies were reported on the prevalence, and relationship between the existence of Helicobacter pylori (H. pylori) in oral cavity and in stomach of patients. The purpose of this study was to systematically review the existing literature on the presence of H. pylori in the oral cavity and its link to gastric infection, the existence of coinfection, and the impact of anti-H. pylori therapy on the dental plaque and vice versa. Method. Two authors independently searched the Medline, EMBASE, Cochrane Library, Web of Science, Google Scholar, and Scopus databases for relevant studies. The articles were analyzed critically and all qualified studies were included. The search was carried out by using a combined text and the MeSH search strategies: using the key words Helicobacter, Helicobacter pylori, and H. pylori in combination with dental plaque, periodontitis, and oral hygiene. Results. The data was presented in 8 tables and each topic separately discussed. Conclusion. Based on the systematic review of the available literature on H. pylori infection and its presence in the oral cavity, it can be concluded that dental plaque can act as a reservoir, and proper oral hygiene maintenance is essential to prevent reinfection. Due to the diversified methods and population groups involved in the available literature, no concrete evidence can be laid down. Further studies are necessary to establish the role of H. pylori in the oral cavity and its eradication on preventing the gastroduodenal infection.

Genetic variation of Helicobacter pylori in the oral cavity and stomach detected using thymine adenine cloning in children with chronic gastritis

OBJECTIVES

To investigate the DNA sequence variations of Helicobacter pylori in the oral cavities and stomachs of children with chronic gastritis.

METHODS

Dental plaques and gargle on 235 patients were obtained before gastroscopy. Gastric H. pylori infection was diagnosed using rapid urease test or Giemsa staining. H. pylori 16S rDNA and CagA gene were analyzed using PCR methods. Thymine adenine cloning-based sequencing was performed in patients with CagA gene positive from oral cavities. The sequence alignments and V1 variable region were evaluated by comparison with the sequence of the standard H. pylori 26695 strain.

RESULTS

Totally, 46 out of the 235 patients were positive for gastric H. pylori infection. Of the 46 patients, 26 cases had amplified H. pylori 16S rDNA in both oral (plaque and gargle) and gastric samples. Of the 26 cases, 12 patients (46.1%) were positive for the H. pylori CagA gene in the oral samples, which was significantly lower than that in the gastric mucosa (80.8%; P = 0.010). The homology of the complete sequence alignment ranged from 74.0% to 92.1% in the oral and gastric samples. The V1 region alleles (positions 75-99) had 7-22 polymorphisms (homology from 12.0% to 72.0%) in 11 patients between the oral and gastric samples, but had 100% homology in 1 patient.

CONCLUSIONS

Our study found that distinct H. pylori strains exist in the oral cavities of children, but we would not support the hypothesis that H. pylori in the oral cavities is an important reservoir of gastric H. pylori infections in children.

Detection of Helicobacter pylori in Oral Lesions

Background and aims. Helicobacter pylori is a microaerophilic gram-negative spiral organism. It is recognized as the etiologic factor for peptic ulcers, gastric adenocarcinoma and gastric lymphoma. Recently, it has been isolated from dental plaque and the dorsum of the tongue. This study was designed to assess the association between H. pylori and oral lesions such as ulcerative/inflammatory lesions, squamous cell carcinoma (SCC) and primary lymphoma.

Materials and methods. A total of 228 biopsies diagnosed as oral ulcerative/inflammatory lesions, oral squamous cell carcinoma (OSCC) and oral primary lymphoma were selected from the archives of the Pathology Department. Thirty-two samples that were diagnosed as being without any pathological changes were selected as the control group. All the paraffin blocks were cut for hematoxylin and eosin staining to confirm the diagnoses and then the samples were prepared for immunohistochemistry staining. Data were collected and analyzed.

Results. Chi-squared test showed significant differences between the frequency of H. pylori positivity in normal tissue and the lesions were examined (P=0.000). In addition, there was a statistically significant difference between the lesions examined (P=0.042). Chi-squared test showed significant differences between H. pylori positivity and different tissue types except inside the muscle layer as follows: in epithelium and in lamina propria (P=0.000), inside the blood vessels (P=0.003), inside the salivary gland duct (P=0.036), and muscle layer (P=0.122).

Conclusion. There might be a relation between the presence of H. pylori and oral lesions. Therefore, early detection and eradication of H. pylori in high-risk patients are suggested.

Presence of different genotypes of Helicobacter pylori in patients with chronic tonsillitis and sleep apnoea syndrome

Helicobacter pylori, a well-known gastric pathogen, has been detected in the oral cavity and oropharynx in tonsillar tissue. In our study, the presence of H. pylori in the tonsillar tissue of patients with chronic tonsillitis and sleep apnoea syndrome (SAS) was investigated. The aim was to detect and genotype H. pylori for a collection of data supporting the possible role of H. pylori in the aetiology of chronic tonsillitis and SAS. Helicobacter pylori was detected by real-time polymerase chain reaction (rt-PCR). 89 patients, 60 with a diagnosis of chronic tonsillitis and 29 with SAS, were tested. In the chronic tonsillitis group, Helicobacter was detected in 48 (80 %) specimens, cagA gene was detected in 12 samples (25 %) and 12 samples were negative. In SAS group, Helicobacter was found in 24 samples (82.76 %), cagA gene was detected in 5 (20.83 %) and 5 samples (17.24 %) were negative. Helicobacter pylori-specific immunoglobulins were tested by ELISA in the serum of 57 patients only with 41 (71.93 %) showing positive. Our results on H. pylori DNA detection and H. pylori seropositivity show 26.32 % discrepancy, slightly in favour of rt-PCR (15.79 % compared to 10.53 %). The H. pylori presence in tonsillar tissue does not depend on the type of oropharyngeal disease (p = 0.756). This study shows that oropharynx constitutes an extragastric reservoir of H. pylori infection which could serve as an aetiopathogenetic factor for chronic tonsillitis and tonsillar hyperplasia by SAS. No conclusion has yet been drawn about the mechanism of the process.

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.

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.

Coccoid Helicobacter pylori exists in the palatine tonsils of patients with IgA nephropathy

PURPOSE

Helicobacter pylori infection is acquired by oral ingestion. H. pylori has been reported to be present in the palatine tonsils. To clarify the route and mode of infection, the prevalence of tonsillar H. pylori was evaluated, and an attempt was made to culture tonsillar H. pylori.

METHODS

In a prospective study, 55 patients with recurrent pharyngotonsillitis or IgA nephropathy underwent a tonsillectomy. The carbon 13-urea breath test and enzyme-linked immunosorbent assay for the detection of H. pylori IgG antibodies in the serum were performed. Tonsillar H. pylori was cultured under conventional culture conditions for gastric H. pylori with or without the following shock methods; heat shock, hydrogen-peroxide-degrading compounds, or parasitizing amoebae. Immunofluorescence and immunoelectron microscopy using antibodies against H. pylori and cytotoxin-associated antigen A were used to identify tonsillar H. pylori.

RESULTS

H. pylori in the coccoid form was present in tonsillar crypts. Of 55 patients, 43 (78.2%) had tonsillar H. pylori, and 15 (27.3%) were infected with gastric H. pylori. All patients with gastric H. pylori also had tonsillar H. pylori (p < 0.01). Cytotoxin-associated antigen A was observed in 38 (88.4%) of 43 tonsillar H. pylori. Tonsillar H. pylori could not be cultured in any culture conditions. All patients with IgA nephropathy had tonsillar H. pylori (p < 0.01).

CONCLUSIONS

The present research might provide some insight into clarifying the route and mode of H. pylori infection. Our findings may indicate that tonsillar H. pylori is one of the antigens causative of IgAN.

Periodontal therapy improves gastric Helicobacter pylori eradication

The oral cavity has been proposed as a reservoir for H. pylori that could be responsible for the refractoriness of gastric infection to triple therapy (antibiotics, antimicrobials, and proton pump inhibitors). The aim of this study was to evaluate the efficiency of combined periodontal and triple therapy vs. triple therapy alone, in gastric H. pylori eradication in persons with H. pylori in the subgingival biofilm. Individuals positive for H. pylori in their gastric and oral samples, as determined by nested PCR, were treated either with periodontal and triple therapy or with triple therapy alone. Our results indicate that 77.3% of those treated with the combined therapy exhibited successful eradication of gastric H. pylori, compared with 47.6% who underwent only triple therapy. Analysis of these data suggests that periodontal treatment in combination with systemic therapy could be a promising approach to increasing the therapy's efficacy and decreasing the risk of infection recurrence.

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.

Unreliability of results of PCR detection of Helicobacter pylori in clinical or environmental samples

The aim of this study was to compare published Helicobacter pylori primer pairs for their ability to reliably detect H. pylori in gastric biopsy specimens and salivary samples. Detection limits of the 26 PCR primer pairs previously described for detection of H. pylori DNA in clinical samples were determined. Sensitivity and specificity were determined using primers with detection limits of <100 CFU/ml using 50 H. pylori-positive and -negative (by concordance by culture and histology) coded gastric biopsy specimens. These results were then confirmed with gastric biopsy specimens and saliva from patients with confirmed H. pylori status. Five of the twenty-six previously reported primer pairs (HP64-f/HP64-r, HP1/HP2, EHC-U/EHC-L, VAG-F/VAG-R, and ICT37/ICT38) had detection limits of <100 CFU/ml in the presence of gastric tissue. None had 100% specificity or sensitivity; all produced false-positive results. The HP64-f/HP64-r for ureA and HP1/HP2 for 16S rRNA individually had sensitivities and specificities of >90% with gastric biopsy specimens. No combinations of primer pairs improved the results. Using these five primer pairs, 54% of the positive saliva samples were determined to be false positive; both the HP64-f/HP64-r and the HP1/HP2 sets produced false positives with saliva. We conclude that clinicians should not rely on results using current PCR primers alone to decide the H. pylori status of an individual patient or as a basis for treatment decisions. The results of studies based on PCR identification of H. pylori in environmental samples should be viewed with caution. Possibly, specific primers sets can be identified based on the presence of multiple putative virulence factor genes.

Four modes of adhesion are used during Helicobacter pylori binding to human mucins in the oral and gastric niches

BACKGROUND

Helicobacter pylori causes peptic ulcer disease and gastric cancer, and the oral cavity is likely to serve as a reservoir for this pathogen. We investigated the binding of H. pylori to the mucins covering the mucosal surfaces in the niches along the oral to gastric infection route and during gastric disease and modeled the outcome of these interactions.

MATERIALS AND METHODS

A panel of seven H. pylori strains with defined binding properties was used to identify binding to human mucins from saliva, gastric juice, cardia, corpus, and antrum of healthy stomachs and of stomachs affected by gastritis at pH 7.4 and 3.0 using a microtiter-based method.

RESULTS

H. pylori binding to mucins differed substantially with the anatomic site, mucin type, pH, gastritis status, and H. pylori strain all having effect on binding. Mucins from saliva and gastric juice displayed the most diverse binding patterns, involving four modes of H. pylori adhesion and the MUC5B, MUC7, and MUC5AC mucins as well as the salivary agglutinin. Binding occurred via the blood-group antigen-binding adhesin (BabA), the sialic acid-binding adhesin (SabA), a charge/low pH-dependent mechanism, and a novel saliva-binding adhesin. In the healthy gastric mucus layer only BabA and acid/charge affect binding to the mucins, whereas in gastritis, the BabA/Le(b)-dependent binding to MUC5AC remained, and SabA and low pH binding increased.

CONCLUSIONS

The four H. pylori adhesion modes binding to mucins are likely to play different roles during colonization of the oral to gastric niches and during long-term infection.

Yeast of the oral cavity is the reservoir of Heliobacter pylori

BACKGROUND

Frequent occurrence of Helicobacter pylori in the human gastrointestinal tract and its persistence due to unsuccessful antimicrobial therapy might be related to a stage in the life cycle of H. pylori in which the bacterium establishes itself as an intracellular symbiont in yeast. In this study, occurrence of non-culturable H. pylori in the oral yeast was assessed by targeting vacuolating cytotoxin A (vacA s1s2) and ureAB genes in the total DNAs of yeasts.

METHODS

DNAs were extracted from 13 oral yeasts in which bacterium-like bodies, suspected to be H. pylori, were observed microscopically. Primers were recruited to amplify vacA s1s2 and ureAB genes. DNAs from H. pylori and E. coli were used as controls. The amplicons from one yeast and H. pylori were sequenced. Yeasts were identified as Candida albicans.

RESULTS

Fragments of vacA s1s2 and ureAB genes were amplified from 13 yeasts. The size of PCR products was 286 bp for vacA s1s2 gene and 406 bp for ureAB gene. Similar bands were obtained from the control H. pylori, and the results for E. coli were negative. The data from sequencing of PCR products showed about 98% homology between the genes amplified from yeast and those from H. pylori.

CONCLUSIONS

The results of this study showed the intracellular occurrence of H. pylori in yeast. This endosymbiotic relationship might explain the persistence of H. pylori in the oral cavity, the consequence of which could be reinoculation of the stomach by the bacterium and spread of infection among human populations.

The transmission of Helicobacter pylori: the effects of analysis method and study population on inference

Although much is known about the virulence of Helicobacter pylori, the transmission pathways for this bacterium are still unresolved. Transmission has been addressed through: (1) prevalence within families; (2) detection in fecal/oral environments; (3) detection in the abiotic/biotic environment; and (4) direct inference from strain similarity. Here, we review the molecular and biochemical methods used and discuss the relative merits of each. Furthermore, as there are differences between developing and developed nations, we discuss the results obtained from transmission studies in light of the study population. We conclude that H. pylori is probably transmitted person-to-person, facilitated by fecal-oral transmission during episodes of diarrhea or gastro-oral contact during periods of vomiting. The persistence of H. pylori in abiotic and biotic environments remains unproven but possible reactivation from viable, non-culturable coccoid forms should be further investigated. Finally, we speculate on the effect of host-pathogen interactions in confounding the inference of transmission.

Implications of oral Helicobacter pylori for the outcome of its gastric eradication therapy

BACKGROUND AND AIMS

Helicobacter pylori (H. pylori) is an important pathogen in gastritis, peptic ulcer and possibly gastric cancer, but several questions remain unanswered. Particularly how the organism is transmitted and what is the relationship between oral presence of H. pylori and the gastric infection. Accordingly, we aimed to characterize the H. pylori in oral cavity and to evaluate its relationship to gastric H. pylori infection.

MATERIALS AND METHODS

Out of total 100 screened for H. pylori infection female subjects (40 to 85 y), 49 patients (pts), who had positive C-urea breath test (UBT) and dyspeptic symptoms, agreed for 1 week regimen of triple anti-H. pylori therapy. The presence of H. pylori in oral cavity was assessed using bacterial culture from saliva and gingival pockets. Gastric H. pylori infection was estimated using capsulated C-urea breath test and plasma anti-H. pylori IgG and saliva IgA antibodies. In addition, plasma gastrin, ghrelin, and pepsinogen I were measured by radioimmunoassay. In selected patients, gastroscopy was additionally performed and gastric biopsy samples were taken for H. pylori random amplification of polymorphic DNA genetic profiling.

RESULTS

The triple therapy resulted in gastric H. pylori eradication in 79% pts, along with significant decrease of plasma gastrin combined with an increase in plasma ghrelin and pepsinogen I (PgI) levels and a marked alleviation of dyspeptic symptoms. In contrast to gastric effects, the eradication therapy failed to cause any changes in the presence of H. pylori in oral cavity. Moreover no relationship was observed between the presence of H. pylori in oral cavity and the gastric H. pylori eradication. In line with these findings, no relationship between gastric and oral H. pylori was found using genetic profiling by random amplification of polymorphic DNA.

CONCLUSIONS

H. pylori was detected both in the oral cavity and the stomach but oral H. pylori had no relation to gastric H. pylori and remained unaffected by eradication of gastric H. pylori.

Are Dental Plaque, Poor Oral Hygiene, and Periodontal Disease Associated WithHelicobacter pyloriInfection?

BACKGROUND

The microorganism Helicobacter pylori has been closely linked to chronic gastritis, peptic ulcer, gastric cancer, and mucosa-associated lymphoid tissue (MALT) lymphoma. Despite the current treatment regimens that lead to successful management of H. pylori-positive chronic gastritis, the reinfection rate is high. It has been suggested that one of the possible mechanisms of reinfection is the recolonization from dental plaque. The purpose of this study was to determine whether dental plaque, poor oral hygiene, and periodontal disease were risk factors for H. pylori infection.

METHODS

Among the 134 patients, 65 patients who had a positive H. pylori serology or positive rapid urease test or histologic evidence for the presence of H. pylori in antral biopsy specimens were categorized as cases. The remaining 69 patients who were negative for H. pylori serology, the rapid urease test, and histology were controls.

RESULTS

It was found that the association of periodontal disease and poor oral hygiene with H. pylori infection was not significant. There was a higher prevalence of H. pylori in the dental plaque of patients with gastric H. pylori infection than in controls, but both groups had a surprisingly high positive urease test for H. pylori in plaque (89% and 71%, respectively).

CONCLUSIONS

H. pylori in dental plaque is seldom eliminated by H. pylori-eradication therapy, and this may act as a source for future reinfection. Hence, eradication of H. pylori from the dental plaque should be made an important part of comprehensive management of H. pylori-associated gastric diseases.

Sensitivity of Helicobacter pylori to an innate defence mechanism, the lactoperoxidase system, in buffer and in human whole saliva

Helicobacter pylori has frequently been isolated from human dental plaque, and oral spread via saliva is thought to be one of its principal modes of transmission. Among other innate defence systems human saliva contains peroxidase enzymes and lysozyme. The sensitivity of H. pylori to physiological concentrations of lactoperoxidase and its salivary substrate thiocyanate, and different amounts of hydrogen peroxide (H(2)O(2)) was investigated in buffer and in human whole saliva. The effect of lysozyme was also studied in saliva. All tested H. pylori strains, ATCC 43504(T) and five clinical isolates, were efficiently inhibited by the peroxidase system with high concentrations of H(2)O(2) in buffer. The inhibition was stronger at lower pH. However, in human saliva these high concentrations of H(2)O(2) generated less hypothiocyanite, the antibacterial product of the peroxidase system and the effects of the peroxidase system were weaker. Physiological concentration of lysozyme was not bacteriocidal against H. pylori, nor did it enhance the effect of the peroxidase system in saliva. Thus, further studies are needed to enhance the efficacy of peroxidase systems in human saliva to make it more beneficial not only against dental but also against gastric pathogens.

Detection of Helicobacter pylori DNA in feces and saliva by polymerase chain reaction: a review

The polymerase chain reaction (PCR), known for its high sensitivity and specificity, has been used for the detection of Helicobacter pylori DNA in bodily materials such as feces and saliva. Since fecal specimens contain PCR inhibitors, DNA before PCR amplification has been purified using various biochemical, immunological and physical pre-PCR steps. Several PCR protocols, differing from each other in the selection of genomic targets and primers, have produced varying degrees of specificity and sensitivity in detecting H. pylori DNA. PCR identified antimicrobial resistance of H. pylori in feces. It also detected virulence factor genes such as the cytotoxin-associated gene (cagA) and vacuolating cytotoxin gene (vacA) in feces and saliva. While the cagA gene was detected in 50-60% of fecal specimens, it was found in 25% of salivary specimens from patients. There was considerable variation in the detection rate of H. pylori DNA in salivary samples. The detection rate in saliva with the most effective primer pair was lower than that observed in feces, making saliva a less suitable specimen for the diagnosis of H. pylori infection. There is controversy regarding the permanent presence of H. pylori in saliva. Whether the salivary and gastric specimens of an individual harbor identical or different strains has not been resolved. PCR cannot distinguish between living and dead organisms. However, it can offer quick results on fecal and salivary specimens, which may contain fastidious and slow-growing H. pylori in low numbers.

Oral Helicobacter pylori: can we stomach it?

Helicobacter pylori infection is one of the most common in man. The bacterium primarily resides in the human stomach, where it plays a significant role in gastric disease. If the spread of H. pylori is to be prevented, an understanding of the transmission process is essential. The oral cavity has been proposed as a reservoir for gastric H. pylori, which has been detected by culture and PCR in both dental plaque and saliva. This review will discuss the evidence for the role of the oral cavity in the transmission of gastric H. pylori. Moreover, the difficulties encountered in addressing this topic, possible directions for future research, and the implications for the dental profession are discussed.

Virulence of water-induced coccoid Helicobacter pylori and its experimental infection in mice

AIM: To explore the virulence and the infectivity of coccoid Helicobacter pylori (H. pylori) transformed from spiral form by exposure to sterile tap water.

METHODS: Three strains of H. pylori, isolated from gastric biopsy specimens of confirmed peptic ulcer, were converted from spiral into coccoid form by exposure to sterile tap water. Both spiral and coccoid forms of H. pylori were tested for the urease activity, and the adherence to Hep-2 cells. The presence of flagella was examined under electron microscopy. In the experimental animal infection, the spiral and coccoid forms of H. pylori originated from the same strain F49 were inoculated intragastrically into BALB/c mice respectively four times at a 3-day interval. Half of the mice from each group were sacrificed at Day 21 and Day 28 after the last inoculation. Histology and H.pylori colonization were detected by urease test of gastric mucosa, cultures of H.pylori, and electron microscopy and so on.

RESULTS: The urease activity and the ability of adherence to Hep-2 cells were found to be lower in coccoid H.pylori than that in its spiral form. For example, the transformation in strain F₄₄ led to a significant decrease of the adherence rate and adherence index from 70.0% ± 5.3% to 30.2% ± 3.5% (P < 0.01), and from 2.6 ± 0.4 to 0.86 ± 0.3 (P < 0.01), respectively. The flagella of coccoid H. pylori were observed under electron microscope. In the experimental infection in mice, the positive rate of gastric mucosa urease test was 93.8% (15/16) in the group infected by spiral H.pylori and 50% (8/16) in the group infected by coccoid H.pylori, and the estimated coccoid H.pylori colony number was 1.75 vs 0.56. The positive rates of H.pylori culture were 87.5% (14/16) in spiral H. pylori group and 68.8% (11/16) in coccoid H. pylori group. There was no significant difference in either urease test or bacterial culture rate between the groups examined at Day 21 and Day 28 after inoculation. Electron microscopic examination of the samples taken from both groups showed the adherence of H.pylori in spiral, bacillary and coccoid shapes to the epithelial cells of gastric wall. Histological examination showed the occurrence of gastric mucosal injury as indicated by various degrees of erosion, ulcer, and inflammatory cell infiltration. Mucosal injury was slighter in the mice infected by coccoid H.pylori. No positive result was obtained in the control group that received intragastrical administration of sterile tap water.

CONCLUSION: Although the virulence of coccoid H.pylori induced by water decrease, coccoid H.pylori still remains a considerable urease activity and the adhering ability to epithelial cells. Furthermore, the flagella, an important component responsible for bacterial movement and infection, were still observed as a cellular structure of coccoid H.pylori under electron microscope. The coccoid H.pylori induced by water is capable of colonizing in gastric mucosa and causing gastrititis in mice.

T-cell-mediated mucosal immunity in the absence of antibody: lessons from Helicobacter pylori infection

Approximately 50% of humanity is infected with Helicobacter pylori. This lifelong infection elicits a marked host response, including a robust gastric IgA response. However, natural infection fails to yield protective immunity. Rather than providing protection, the chronic inflammatory response associated with natural infection can contribute to tissue damage and the pathogenesis of gastroduodenal disease, including atrophic gastritis, peptic ulcer, and gastric cancer. These immune responses are attributed to a subset of helper T cells, so-called Th1 cells, that enhance cell-mediated immunity and induce damage to the gastric epithelium. Thus, it is desirable to have effective vaccines that could prevent and cure infection and that may modify the host response in a manner that prevents immune-mediated disease. Using animal models as a tool to understand the immunobiology of Helicobacter infections, several investigators have shown that effective vaccines can be developed. Thus, prophylactic and even therapeutic vaccines have been described in various animal models. The basis for the effectiveness of these vaccines appears related to their ability to alter the gastric immune response, from a homogeneous Th1 response to a mixed Th1 and Th2 response. Interestingly, immunity can occur in the absence of B cells, suggesting that novel IgA-independent mechanisms exist that confer protection against a luminal infection. Thus, H. pylori infection provides a model with which new mechanisms of immunological protection can be identified and applied to other mucosal infections.