Absence of Helicobacter pylori within the oral cavities of members of a healthy South African community

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.

Evaluating CagA and VacA Oncoproteins of Helicobacter pylori in Oral Potentially Malignant Disorders

Oral Potentially Malignant Disorders such as leukoplakia, lichenplanus, Oral Submucous Fibrosis are most commonly encountered precancerous lesions in India. Although, usage of smoking tobacco has been decreased yet incidence of oral cancer seems to be in increasing trend. Apart from tobacco many non-tobacco causes are associated with the disease. Helicobacter pylori is a curved, flagellated bacterium that has been declared as group I carcinogen by WHO. They are proven causative agent for gastric carcinoma. They have been shown to harbour oral cavity by many authours. They produce onco-protein that causes DNA damage. CagA and VacA are such proteins that modulate certain oncogenes and tumour suppressor genes. In this study we have identified the organism from sub gingival plaque by PCR and those who harboured the organism were further subjected for identification of oncoproteins CagA and VacA by ELISA. This study shows that presence of organism in Oral leucoplakia, oral lichenplanus and Oral Submucous Fibrosis are statistically significant in comparison to control group (p>0.05). The presence of oncoproteins was also statistically significant in comparison to control group. These proteins are shown to accelerate inflammatory pathway thereby hasten the process of tumorigenesis. H.pylori infection as well the virulent strains can be diagnosed from oral cavity in the most non-invasive way at the earliest.

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.

Association of Helicobacter pylori with oral potentially malignant disorders and oral squamous cell carcinoma-a systematic review and meta-analysis

OBJECTIVE

To assess any potential association between Helicobacter pylori and oral squamous cell carcinoma/oral potentially malignant disorders.

MATERIALS AND METHODS

Data mining was done using PubMed, Cochrane Library, and SCOPUS databases. The search included articles published up to May 2019. Newcastle-Ottawa scale was used to score the quality of the included articles. Data including the type of study, the sample population, the type of oral lesion, and the resulting statistical data were extracted.

RESULTS

Out of 131 screened articles, only 15 articles fulfilled the eligibility criteria. Among the 15 studies, 9 focused on oral squamous cell carcinoma and 6 focused on oral potentially malignant disorders. Eight out of the 9 oral squamous cell carcinoma studies were included in the meta-analysis. Forest plot was generated using the odds ratio and confidence intervals calculated for each of the included studies. Due to the lack of sufficient studies, the meta-analysis was not performed for oral potentially malignant disorders.

CONCLUSION

Due to the contradictory results of the included studies, it was not possible to make any conclusive statement on the potential association of H. pylori with oral squamous cell carcinoma. The variations in the methodology, especially the differences in the sensitivity/specificity of the diagnostic modalities could be the cause for differential results.

CLINICAL RELEVANCE

Although the association of H. pylori with oral squamous cell carcinoma could not be confirmed, it is vital to reduce the excess oral microbial load, especially in patients exhibiting oral mucosal changes with no history of associated risk factors.

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.

The use of stool specimens reveals Helicobacter pylori strain diversity in a cohort of adolescents and their family members in a developed country

Helicobacter pylori infection occurs within families but the transmission route is unknown. The use of stool specimens to genotype strains facilitates inclusion of complete families in transmission studies. Therefore, we aimed to use DNA from stools to analyze strain diversity in H. pylori infected families. We genotyped H. pylori strains using specific biprobe qPCR analysis of glmM, recA and hspA. Concentration of H. pylori organisms before DNA isolation enhanced subsequent DNA amplification. We isolated H. pylori DNA from 50 individuals in 13 families. T_m data for at least 2 of the 3 genes and sequencing of the glmM amplicon were analyzed. Similar strains were commonly found in both mothers and children and in siblings. However, 20/50 (40%) individuals had multiple strains and several individuals harbored strains not found in other family members, suggesting that even in developed countries sources of infection outside of the immediate family may exist. Whether infection occurs multiple times or one transmission event with several strains occurs is not known but future studies should aim to analyze strains from children much closer to infection onset. The presence of multiple stains in infected persons has implications for antibiotic sensitivity testing and treatment strategies.

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

Background

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

Methods

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

Results

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

Conclusions

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

Electronic supplementary material

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

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.

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.

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.

Helicobacter pylori identification: a diagnostic/confirmatory method for evaluation

The Helicobacter pylori extra gastric reservoir is probably the oral cavity. In order to evaluate the presence of this bacterium in patients with periodontitis and suspicious microbial cultures, saliva was collected from these and non-periodontitis subjects. PCRs targeting 16S rRNA gene and a 860 bp specific region were performed, and digested with the restriction enzyme DdeI. We observed that the PCR-RFLP approach augments the accuracy from 26.2 % (16/61), found in the PCR-based results, to 42.6 % (26/61), which is an excellent indicator for the establishment of this low-cost procedure as a diagnostic/confirmatory method for H. pylori evaluation.

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.

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.

Genomic evolution and transmission of Helicobacter pylori in two South African families

Helicobacter pylori infects the stomachs of one in two humans and can cause sequelae that include ulcers and cancer. Here we sequenced the genomes of 97 H. pylori isolates from 52 members of two families living in rural conditions in South Africa. From each of 45 individuals, two H. pylori strains were isolated from the antrum and corpus parts of the stomach, and comparisons of their genomes enabled us to study within-host evolution. In 5 of these 45 hosts, the two genomes were too distantly related to be derived from each other and therefore represented evidence of multiple infections. From the remaining 40 genome pairs, we estimated that the synonymous mutation rate was 1.38 × 10(-5) per site per year, with a low effective population size within host probably reflecting population bottlenecks and immune selection. Some individuals showed very little evidence for recombination, whereas in others, recombination introduced up to 100-times more substitutions than mutation. These differences may reflect unequal opportunities for recombination depending on the presence or absence of multiple infections. Comparing the genomes carried by distinct individuals enabled us to establish probable transmission links. Transmission events were found significantly more frequently between close relatives, and between individuals living in the same house. We found, however, that a majority of individuals (27/52) were not linked by transmission to other individuals. Our results suggest that transmission does not always occur within families, and that coinfection with multiple strains is frequent and evolutionarily important despite a fast turnover of the infecting strains within-host.

Immunohistochemical detection of Helicobacter pylori without association of TLR5 expression in oral squamous cell carcinoma

BACKGROUND

Approximately 15% of human deaths from cancer are associated with chronic viral or bacterial infections. Helicobacter pylori (HP), a flagellated, Gram-negative, spiral, microaerophilic bacteria is considered to be the most common chronic bacterial infection in humans. Toll-like receptor 5 (TLR5) is involved in recognition of bacterial flagella and is thought to promote tumour growth through inflammation-dependent mechanisms in epithelial cells.

METHODS

Expression of HP and TLR5 was analysed in OSCC specimen (n = 191) by immunohistochemistry. TLR5 expression specificity was conducted by Western blotting in cancer cell lines (BICR3, BICR56). TLR5-stained sections were scanned and digitally analysed using ImageJ and the immunomembrane plug-in. HP expression and TLR5 expression were associated with clinicopathological characteristics and impact on survival.

RESULTS

Helicobacter pylori detection was significantly associated with recurrence of the tumour, whereas TLR5 expression was not. Multivariate analysis demonstrated HP expression as an independent prognostic factor (P = 0.0260). TLR5 specificity was confirmed by Western blot analysis.

CONCLUSIONS

For the first time, this study provides evidence that immunohistochemically detected HP expression in OSCC is associated with reduced disease-free survival in a large patient cohort. Although TLR5 was not associated with any clinicopathological characteristics or impact on survival, investigation of the TLR family seems to be reasonable due to the possible existence of other pathogenic bacterial or viral compounds in oral cavity cancer.

Study of Helicobacter pylori genotype status in saliva, dental plaques, stool and gastric biopsy samples

AIM: To compare genotype of Helicobacter pylori (H. pylori) isolated from saliva, dental plaques, gastric biopsy, and stool of each patient in order to evaluate the mode of transmission of H. pylori infection.

METHODS: This cross-sectional descriptive study was performed on 300 antral gastric biopsy, saliva, dental plaque and stool samples which were obtained from patients undergoing upper gastrointestinal tract endoscopy referred to endoscopy centre of Hajar hospital of Shahrekord, Iran from March 2010 to February 2011. Initially, H. pylori strains were identified by rapid urease test (RUT) and polymerase chain reaction (PCR) were applied to determine the presence of H. pylori (ureC) and for genotyping of voculating cytotoxin gene A (vacA) and cytotoxin associated gene A (cagA) genes in each specimen. Finally the data were analyzed by using statistical formulas such as Chi-square and Fisher’s exact tests to find any significant relationship between these genes and patient’s diseases. P < 0.05 was considered statistically significant.

RESULTS: Of 300 gastric biopsy samples, 77.66% were confirmed to be H. pylori positive by PCR assay while this bacterium were detected in 10.72% of saliva, 71.67% of stool samples. We were not able to find it in dental plaque specimens. The prevalence of H. pylori was 90.47% among patients with peptic ulcer disease (PUD), 80% among patients with gastric cancer, and 74.13% among patients with none ulcer dyspepsia (NUD) by PCR assay. The evaluation of vacA and cagA genes showed 6 differences between gastric biopsy and saliva specimens and 11 differences between gastric and stool specimens. 94.42% of H. pylori positive specimens were cagA positive and all samples had amplified band both for vacA s and m regions. There was significant relationship between vacA s1a/m1a and PUD diseases (P = 0.04), s2/m2 genotype and NUD diseases (P = 0.05). No statically significant relationship was found between cagA status with clinical outcomes and vacA genotypes (P = 0.65). The evaluation of vacA and cagA genes showed 6 differences between gastric biopsy and saliva specimens and 11 differences between gastric and stool specimens.

CONCLUSION: Regard to high similarity in genotype of H. pylori isolates from saliva, stomach and stool, this study support the idea which fecal- oral is the main route of H. pylori transmission and oral cavity may serve as a reservoir for H. pylori, however, remarkable genotype diversity among stomach, saliva and stool samples showed that more than one H. pylori genotype may exist in a same patient.

Is Helicobacter pylori resident or transient in the human oral cavity?

Helicobacter pylori colonizes the stomachs of at least half of the world's human population. The role of the oral cavity in this colonization is not clear and there are, to date, no comprehensive data that clearly demonstrate the isolation of this bacterium from the oral cavity. The aim of this study was to evaluate the prevalence of H. pylori in the oral cavity of 15 patients who tested positive for H. pylori. A comprehensive dental examination of all patients was conducted. Samples were taken from supragingival and subgingival plaque, saliva, periapical exudates and tongue swabs. All samples were taken before the application of antibiotics. A total of 163 oral samples were investigated by PCR using two different H. pylori-specific primer pairs. A PCR inhibition control using a modified plasmid was always included for the most specific primer pair. In addition, a culture technique was used to confirm PCR results. Despite a PCR detection limit of 10(2) bacteria ml(-1), out of 14 patients, H. pylori could not be detected in any of the samples taken. In one patient, H. pylori-positive PCR signals were obtained in two samples using only one primer pair. H. pylori could not be cultivated from these two PCR-positive samples; therefore, no correlation to oral colonization status could be established. This study challenges the misleading preconception that H. pylori resides in the human oral cavity and suggests that this bacterium should be considered transient and independent of the oral status. To date, positive PCR results for H. pylori in the oral cavity have been overestimated and not critically interpreted in literature.

Helicobacter pylori transiently in the mouth may participate in the transmission of infection

Helicobacter pylori infection is associated with peptic ulcer and gastric carcinoma. The oral cavity may be a reservoir for H. pylori; however, the results of studies on this subject are controversial. We employed single-step and nested polymerase chain reactions (PCR) to detect the presence of the vacA, ureA and 16S rDNA genes of H. pylori in the stomach, saliva and dental plaque of 30 subjects. The results were confirmed by sequencing. Nested 16S rDNA and ureA amplification was achieved in 80% of gastric, 30% of saliva and 20% of dental plaque specimens. Sequencing of 10, seven and four 16S rDNA products from stomach, saliva and dental plaque, respectively, showed > 99% identity with H. pylori. Sequencing of the other four oral cavity PCR products showed similarity with Campylobacter and Wolinella species. Additionally, the vacA genotype identified in the samples of different sites was the same within a given subject.H. pylori may be found in the oral cavity of patients with gastric infection, thus it could be a source of transmission. However, results obtained with detection methods based only on PCR should be interpreted with caution because other microorganisms that are phylogenetically very close to H. pylori are also present in the mouth.

Helicobacter pylori in dental plaque and stomach of patients from Northern Brazil

AIM: To establish whether virulence factor genes vacA and cagA are present in Helicobacter pylori (H. pylori) retrieved from gastric mucosa and dental plaque in patients with dyspepsia.

METHODS: Cumulative dental plaque specimens and gastric biopsies were submitted to histological examination, rapid urease test and polymerase chain reaction (PCR) assays to detect the presence of cagA and vacA polymorphisms.

RESULTS: Detection of H. pylori from dental plaque and gastric biopsy samples was greater by PCR compared to histological examination and the rapid urease test. DNA from H. pylori was detected in 96% of gastric mucosa samples and in 72% of dental plaque samples. Sixty-three (89%) of 71 dental plaque samples that were H. pylori-positive also exhibited identical vacA and cagA genotypes in gastric mucosa. The most common genotype was vacAs1bm1 and cagA positive, either in dental plaque or gastric mucosa. These virulent H. pylori isolates were involved in the severity of clinical outcome.

CONCLUSION: These pathogenic strains were found simultaneously in dental plaque and gastric mucosa, which suggests that gastric infection is correlated with the presence of H. pylori in the mouth.

Effect of dental plaque control on infection of Helicobacter pylori in gastric mucosa

BACKGROUND

Data on the role of dental plaque in the transmission of Helicobacter pylori have varied. Furthermore, there has been few reports on the relationship between dental plaque control and H. pylori infection of gastric mucosa. The purpose of this study was to elucidate this potential relationship.

METHODS

The (13)C urea breath test was conducted on 56 subjects who received dental plaque control and 51 subjects who did not.

RESULTS

The prevalence of H. pylori in the gastric mucosa was 19.64% in patients who received dental plaque control, which was significantly lower than in those without dental plaque control (84.31%).

CONCLUSION

Long-term professional dental plaque control was associated with less gastric reinfection by H. pylori, suggesting that dental plaque control may help to prevent H. pylori-induced gastric disease or reinfection.

Presence of Helicobacter pylori in betel chewers and non betel chewers with and without oral cancers

BACKGROUND

Betel chewing has been shown to predispose to periodontal disease and oral cancer. Studies show that people with gum disease are more likely to test positive for Helicobacter pylori (H. pylori). It is not known if the lesions produced by betel quid and the resulting, chemical changes predispose to colonization by H. pylori. Further the role of this organism in oral cancer is not known. Our objective was to determine the presence of H. pylori in oral lesions of thirty oral cancer patients and to determine the presence of IgG antibodies to H. pylori in oral cancer patients who are betel chewers and non betel chewers, healthy betel chewers and healthy non-betel chewers and to compare the presence of H. pylori in these four groups. This case control study was conducted at the Cancer Institute Maharagama and the Department of Microbiology, Faculty of Medical Sciences, University of Sri Jayewardenepura.

METHODS

One hundred and seventy three subjects, of whom fifty three were patients presenting with oral cancer to the Cancer Institute Maharagama, sixty healthy betel chewers and sixty healthy non-betel chewers from the Religious and Welfare Service Centre Maharagama were tested for H. pylori by serology. Thirty oral biopsies from oral cancer patients were cultured under microaerophilic condition to isolate H. pylori. The statistic used was Chi-square test.

RESULTS

Of the fifty-three oral cancer patients, forty-four were betel chewers. Among the 53 oral cancer patients examined, ten of forty-four (10/44 = 22.7%) patients who are betel chewers and four of nine (4/9 = 44.4%) patients who are non-betel chewers were detected positive for IgG antibody against H. pylori. In the healthy group (betel chewers and non betel chewers) ten (16.7%) of the healthy betel chewers tested positive for H. pylori by serology. None of the healthy non-betel chewers tested positive for H. pyloriFourteen [26.4%] of oral cancer patients tested positive for H. pylori by serology, of which two were also culture positive (Only thirty samples were cultured). The presence of H. pylori in betel chewers (with or without cancer) compared to non-betel chewers was statistically significant. (Chi-square test p < 0.05) The use of tobacco and areca nut in betel chewers was significant with the presence of H. pylori (p < 0.05).

CONCLUSION

There is a significant higher proportion of H. pylori in betel chewers compared to non-betel chewers but not between oral cancer patients compared to patients without oral cancer. Hence Betel chewing may predispose to colonisation with H. pylori in the digestive tract through swallowing the quid or during betel chewing.

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 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.

Horizontal versus familial transmission of Helicobacter pylori

Transmission of Helicobacter pylori is thought to occur mainly during childhood, and predominantly within families. However, due to the difficulty of obtaining H. pylori isolates from large population samples and to the extensive genetic diversity between isolates, the transmission and spread of H. pylori remain poorly understood. We studied the genetic relationships of H. pylori isolated from 52 individuals of two large families living in a rural community in South Africa and from 43 individuals of 11 families living in urban settings in the United Kingdom, the United States, Korea, and Colombia. A 3,406 bp multilocus sequence haplotype was determined for a total of 142 H. pylori isolates. Isolates were assigned to biogeographic populations, and recent transmission was measured as the occurrence of non-unique isolates, i.e., isolates whose sequences were identical to those of other isolates. Members of urban families were almost always infected with isolates from the biogeographic population that is common in their location. Non-unique isolates were frequent in urban families, consistent with familial transmission between parents and children or between siblings. In contrast, the diversity of H. pylori in the South African families was much more extensive, and four distinct biogeographic populations circulated in this area. Non-unique isolates were less frequent in South African families, and there was no significant correlation between kinship and similarity of H. pylori sequences. However, individuals who lived in the same household did have an increased probability of carrying the same non-unique isolates of H. pylori, independent of kinship. We conclude that patterns of spread of H. pylori under conditions of high prevalence, such as the rural South African families, differ from those in developed countries. Horizontal transmission occurs frequently between persons who do not belong to a core family, blurring the pattern of familial transmission that is typical of developed countries. Predominantly familial transmission in urban societies is likely a result of modern living conditions with good sanitation and where physical contact between persons outside the core family is limited and regulated by societal rules. The patterns observed in rural South African families may be representative of large parts of the developing world.

More than half of the world population is infected with Helicobacter pylori. It was widely believed that the primary mode of transmission is intra-familial, but the chains of infection are poorly understood. We have applied multilocus sequence analysis to H. pylori from two large multi-generation families in rural South Africa. Observations were compared with H. pylori from small, nuclear families in urban areas of the United States, United Kingdom, Colombia, and Korea, as well as with a large global collection from unrelated individuals. Intra-familial transmission of H. pylori was common in urban families but less common in the rural South African families. Instead, the South African families were infected with widely diverse strains, and multiple infections were common. We argue that the apparent predominance of intra-familial transmission in urban societies is a result of good socioeconomic conditions. In high-prevalence areas, opportunities for horizontal transmission are higher, which can result in greater diversity of H. pylori within a family. The patterns of frequent horizontal spread in rural South African families may be representative of large parts of the developing world. This interpretation is supported by the global sample which yielded ample evidence for horizontal inter-familial transmission in many areas of the world.

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

BACKGROUND

Helicobacter pylori has been associated with the development of peptic ulcers and gastric cancer. Although the oral cavity may be a source of transmission, it is unknown whether it acts as a permanent reservoir for this bacterium, particularly in the presence of periodontal disease. The purpose of this study was to evaluate the prevalence of H. pylori by polymerase chain reaction (PCR) in the subgingival biofilm and saliva of subjects with periodontitis.

METHODS

Samples were obtained from 56 periodontally healthy subjects and 169 subjects with chronic periodontitis. DNA was extracted from the samples, and the detection of H. pylori was carried out by PCR using the JW22/23 primers.

RESULTS

In general, H. pylori was detected in 24% of all samples evaluated. A significantly higher prevalence of H. pylori was observed in subgingival biofilm samples (33.3%) compared to saliva samples (20%) (P <0.05). H. pylori was detected significantly more often in the saliva and subgingival samples from subjects with periodontitis (23.5% and 50%, respectively) compared to samples from periodontally healthy subjects (7.3% and 11.4%, respectively; P <0.05).

CONCLUSION

H. pylori was detected frequently in the oral microbiota of subjects with periodontitis, suggesting that periodontal pocketing and inflammation may favor the colonization by this species.

A new model for the transmission of Helicobacter pylori: role of environmental reservoirs as gene pools to increase strain diversity

Twenty-five years after the first successful cultivation and isolation of Helicobacter pylori, the scientific community is still struggling to understand the way(s) this bacterium is transmitted among the human population. Here, both epidemiologic and microbiologic evidence addressing this matter is reviewed and explored to conclude that most H. pylori successful colonizations are derived from direct person-to-person contact and that even though exposure of humans to H. pylori from environmental sources is a very common event, in most occasions the host is able to fight off infection. In addition, under a new model developed here, we propose that the near elimination of environmental reservoirs is the main responsible for the lower prevalence observed in the more industrialized countries by acting on two levels: by decreasing the number of direct infections and by diminishing the number of intraspecies recombination events for producing strain variation within H. pylori.

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.

Comparison of different methods to detect Helicobacter pylori in the dental plaque of dyspeptic patients

The aim of this study was to compare different methods of detection of Helicobacter pylori (H. pylori) in the dental plaque of dyspeptic patients. After recording the clinical indices, culture and polymerase chain reaction (PCR) methods were performed on plaque samples, while rapid urease test in addition to these tests was carried on gastric samples from 67 dyspeptic patients who attended for an upper gastrointestinal endoscopy. Forty-seven of 67 patients were H. pylori-positive in gastric biopsy material whereas the microbial dental plaque from 19 patients demonstrated H. pylori positivity detected by PCR. Among the patients, 25.4% harbored H. pylori both in the stomach and in microbial dental plaque. No significant correlations were found among the presence of H. pylori in the stomach, in plaque, and clinical variables (P > 0.05). Although oral hygiene was observed optimal and the mean of pocket depth was not found to be higher, the prevalence of H. pylori was observed to be higher in dental plaque. According to our results, PCR technique gave the highest detection rate both in gastric biopsy and in dental plaque compared to the other methods used.

Absence of Helicobacter pylori in the oral cavity of 10 non-dyspeptic subjects demonstrated by real-time polymerase chain reaction

Helicobacter pylori plays a significant role in gastric disease. However, the presence of this bacterium in the oral cavity remains controversial. The aim of the present study was to detect and quantify H. pylori in 29 different sites of the oral cavity in non-dyspeptic subjects by means of real-time polymerase chain reactions (PCR). Ten subjects without gastric symptoms were studied. Samples from unstimulated saliva, three sites of the tongue, oral mucosa, and 12 sites of both supragingival and subgingival plaque were collected from each subject. DNA was extracted from the oral samples and analysed for the presence of H. pylori by real-time PCR (LightCycler) using JW23/22 primers which targeted the 16S rRNA gene. DNA from H. pylori DSM 4867 was used as a positive control. Amplification efficiency for the LightCycler 2.0 runs ranged from 1.8 to 2.4. Melting curve analysis identified all the positive control capillaries, which contained H. pylori reference DNA, as a single and narrow peak at a melting temperature between 84.5 and 84.9 degrees C. All the negative control capillaries with no template control and the 29 oral samples from each subject showed either no melting peaks or broad melting peaks below 80 degrees C, which were considered as primer dimers. Therefore, H. pylori was not detected from any of the 290 oral samples. As a conclusion, H. pylori seems not to be permanently present in the oral cavity of a non-dyspeptic population.

Prevalence of Campylobacter species, Helicobacter pylori and Arcobacter species in stool samples from the Venda region, Limpopo, South Africa: studies using molecular diagnostic methods

OBJECTIVES

This study determined the prevalence of Campylobacter spp., Helicobacter pylori and Arcobacter spp. in stool samples from Venda in relation to diarrhea, intestinal inflammation and HIV status using specific molecular methods.

METHODS

Stool samples were collected from hospital patients (255) and primary school children (67). Genomic DNA was extracted from the stools and molecular methods including PCR, PCR followed by restriction analysis and multiplex PCR were used to test for the different organisms. The lactoferrin content of the stools was determined using commercial kits from TechLab (Blacksburg, VA, USA).

RESULTS

The prevalence of the different organisms was 50.6% for H. pylori, 10.2% for C. jejuni, 6.2% for A. butzleri, 6.5% for C. coli, 3.1% for C. concisus, 2.8% for A. cryaerophilus and 1.9% for A. skirrowii. Of all the organisms, only C. jejuni was significantly associated with diarrhea (84.8%) (chi2=21.025, P<0.001) and elevated levels of lactoferrin (78.8%) (chi2=16.919, P<0.005) and was an important pathogen associated with diarrhea among HIV positive individuals (22.8%).

CONCLUSIONS

Campylobacter infections are common causes of gastroenteritis in Venda. Non-C. jejuni/coli Campylobacters such as C. concisus as well as A. butzleri and H. pylori may be involved in gastrointestinal diseases in the region but further studies are needed to confirm this hypothesis.

A population genetics pedigree perspective on the transmission of Helicobacter pylori

The inference of transmission pathways for medicinally important bacteria is important to our understanding of pathogens. Here we report analyses of transmission in Helicobacter pylori, a major carcinogen. Our study is novel in that the focal community comprises detailed family pedigrees and has a high prevalence of H. pylori. To infer transmission, we performed high-resolution analyses of nucleotide sequences for three genes and accounted for the occurrence of mutation and recombination through the use of simulation modeling. Our results demonstrate that transmission has a strong nonfamilial component potentially the result of a large proportion of infections derived from the community. These results are interesting from both a medical and an evolutionary standpoint. First, efficient control measures and beliefs about the sources of H. pylori infection should be reevaluated. Evolutionarily, our results contradict the hypothesis of strict vertical transmission, presented as an explanation for the strong correlation between human population history and H. pylori diversity. Thus the paradox of persistent phylogenetic structure, despite a permissive mode of transmission and high recombination rates, must be solved elsewhere. Here we consider the potential for recombination events to maintain genetic structure in light of horizontal transmission.

Incidence of Helicobacter felis and the effect of coinfection with Helicobacter pylori on the gastric mucosa in the African population

Helicobacter pylori and Helicobacter felis are two of the Helicobacter spp. that infect humans. H. pylori has been linked to significant gastric pathology. Coinfection with Helicobacter spp. may influence infectious burden, pathogenesis, and antibiotic resistance; however, this has not been studied. The aims of this study were to identify the incidence of H. felis and to analyze the effects of coinfection with both organisms on gastric pathology in a well-characterized South African population. Biopsy samples from the gastric corpora and antra of volunteers (n = 90) were subjected to histological examination and PCR for the identification of H. pylori and H. felis. We further investigated the effect of global strain type on the occurrence of precursor lesions by assigning nucleotide sequences derived from PCR amplification of three genes to global groupings (ancestral Africa1, ancestral Africa2, ancestral Europe, ancestral Asia, and mixed). H. pylori was detected in 75 (83.3%), H. felis in 23 (25.6%), and coinfection in 21 (23.3%) of the volunteers by PCR. H. felis was randomly distributed among adults and children but clustered within families, suggesting intrafamilial transmission. Analysis of histopathology scores revealed no differences in atrophy, activity, and helicobacter density between H. felis-positive and H. felis-negative volunteers. H. pylori substrains common to southern Africa showed no differences in inflammation or atrophy scores. The incidences of H. felis and coinfection with H. pylori in the African population are high. H. felis infection, however, does not influence specific gastric pathology in this population.