Correlation between virulence markers of Helicobacter pylori in the oral cavity and gastric biopsies

Helicobacter pylori in oral cavity: current knowledge

The oral cavity may play a role as a reservoir and in the transmission and colonization of Helicobacter pylori. The route of transmission for H. pylori is not fully understood. The prevalence of this pathogen varies globally, affecting half of the world's population, predominantly in developing countries. Here, we review the prevalence of H. pylori in the oral cavity, the characteristics that facilitate its colonization and dynamics in the oral microbiome, the heterogeneity and diversity of virulence of among strains, and noninvasive techniques for H. pylori detection in oral samples. The prevalence of H. pylori in the oral cavity varies greatly, being influenced by the characteristics of the population, regions where samples are collected in the oral cavity, and variations in detection methods. Although there is no direct association between the presence of H. pylori in oral samples and stomach infection, positive cases for gastric H. pylori frequently exhibit a higher prevalence of the bacterium in the oral cavity, suggesting that the stomach may not be the sole reservoir of H. pylori. In the oral cavity, H. pylori can cause microbiome imbalance and remodeling of the oral ecosystem. Detection of H. pylori in the oral cavity by a noninvasive method may provide a more accessible diagnostic tool as well as help prevent transmission and gastric re-colonization. Further research into this bacterium in the oral cavity will offer insights into the treatment of H. pylori infection, potentially developing new clinical approaches.

Helicobacter pylori infection: A balance between bacteria and host

In Argentina, despite the important studies conducted on the prevalence of infection and the antibiotic resistance of Helicobacter pylori, there are no reports simultaneously analyzing a profile of virulence factors of the bacterium and polymorphisms in cytokine genes in patients with different alterations in the gastric mucosa (including intestinal metaplasia, IM). Our aim was to evaluate H. pylori genotypes in 132 adult patients with chronic gastritis presenting three different histological findings (inactive chronic gastritis, active chronic gastritis IM- and active chronic gastritis IM+) along with SNP-174 G>C in the IL-6 gene. cagA, vacA and babA2 genes were analyzed by multiplex PCR. The -174 G>C SNP IL-6 gene was analyzed by PCR-RFLP. Patients with active chronic gastritis IM+ showed the highest proportion of the cagA(+)/IL-6GG, cagA(+)/vacAm1s1/IL-6GG and cagA(+)/vacAm1s1/babA2(+)/IL-6GG combinations (p<0.05). There was 4-5 times greater probability of finding patients presenting the GG genotype for SNP-174 G>C IL-6, which in turn were infected with the most virulent H. pylori genotypes -cagA(+), cagA(+)/vacAm1s1 and cagA(+)/vacAm1s1/babA2- in the ACGIM+ group in comparison to the ICG group. Our results provide regional data to the idea that the transition towards severe alterations in the gastric mucosa would be the result of a balance between specific factors of H. pylori and inherent host factors. This fact can be useful to identify patients at greater risk and to select those individuals requiring appropriate eradication treatment to prevent progression to gastric cancer.

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

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

Comparing the prevalence of Helicobacter pylori and virulence factors cagA, vacA, and dupA in supra-gingival dental plaques of children with and without dental caries: a case-control study

BACKGROUND

Helicobacter pylori infection is one of the most common infectious diseases in humans. Dental plaque is considered as a reservoir of this bacterium, which could play an important role in the development of gastrointestinal problems. Our aim was to investigate the prevalence of H. pylori and its virulence factors in dental plaques in children with and without dental caries.

METHODS

Among children aged 6 to 12 years, a total of 72 children were enrolled in the study, including 36 cases with total DMFT/dmft > 3 (case group) and 36 participants with total DMFT/dmft < 1 (control group). After removing supra-gingival plaques from the lower first permanent molar teeth, the samples were examined using PCR method for the presence of H. pylori and some of its virulence factors. Statistical analysis was performed using chi-square, Fisher' exact test, t-tests, and logistic regression.

RESULTS

Of 72 participants, 40 cases were male, and 32 cases were female. The minimum and maximum values of total DMFT/dmft indices were zero and ten, respectively, and the mean ± SD value of total DMFT/dmft was 2.78 ± 3.22. Except for vegetable consumption (p = 0.045), there was no significant difference between the two groups regarding gastrointestinal disorders, feeding methods in infancy (p = 0.058), frequency of daily brushing (p = 0.808), frequency of dental visits (p = 0.101), and history of dental scaling (p = 0.246) and professional topical fluoride therapy (p = 0.5). Out of 72 samples, 15 cases were positive for H. pylori DNA (20.8%), and there was no significant association between the presence of this bacterium in dental plaque and dental caries (p = 0.281). The frequency of virulence factors detected in 15 H. pylori cases was as follows: cagA in six cases (40.0%), vacAm1 in three cases (20.0%), and vacAs1 in one case (6.7%). There was no significant difference between the groups regarding the prevalence of virulence factors.

CONCLUSION

Our results indicate the presence of H. pylori along with some virulence factors in dental plaques as a reservoir of this bacterium in children in Iran. Although there was no significant association between this bacterium and the incidence of dental caries, dental health in children needs to be seriously taken into consideration.

Colonization of Helicobacter pylori in the oral cavity - an endless controversy?

Helicobacter pylori is associated with chronic gastritis, gastric or duodenal ulcers, and gastric cancer. Since the oral cavity is the entry port and the first component of the gastrointestinal system, the oral cavity has been discussed as a potential reservoir of H. pylori. Accordingly, a potential oral-oral transmission route of H. pylori raises the question concerning whether close contact such as kissing or sharing a meal can cause the transmission of H. pylori. Therefore, this topic has been investigated in many studies, applying different techniques for detection of H. pylori from oral samples, i.e. molecular techniques, immunological or biochemical methods and traditional culture techniques. While molecular, immunological or biochemical methods usually yield high detection rates, there is no definitive evidence that H. pylori has ever been isolated from the oral cavity. The specificity of those methods may be limited due to potential cross-reactivity, especially with H. pylori-like microorganisms such as Campylobacter spp. Furthermore, the influence of gastroesophageal reflux has not been investigated so far. This review aims to summarize and critically discuss previous studies investigating the potential colonization of H. pylori in the oral cavity and suggest novel research directions for targeting this critical research question.

Detection of Helicobacter pylori in oral yeasts from students of a Chilean university

INTRODUCTION

Nearly 73% of the Chilean population is infected with Helicobacter pylori (H. pylori), a factor predisposing for gastric cancer. Recent studies have demonstrated the presence of this pathogen within yeasts, suggesting that this fact can directly influence the failure of a treatment, transmission, and reinfection.

AIM

To detect the presence of H. pylori inside oral yeasts isolated from students of the University of Concepción (Chile).

METHODS

72 samples, obtained from the oral cavity using cotton swabs were incubated in YPD broth for 48h at 37°C and posteriorly seeded in Sabouraud Dextrose agar plus chloramphenicol at the same temperature and for the same time. Yeasts isolated were observed microscopically (wet mounting and Gram-stained) and identified using microbiological techniques. Intracellular H. pylori detection was performed by the amplification of 16S rDNA by PCR.

RESULTS

Oral yeasts were detected in 24 samples (33.3%), being C. albicans (79.2%) the most frequent species, followed by C. dubliniensis (12.4%), C. krusei (4.2%), and C. tropicalis (4.2%). When analyzed by PCR, 15 of the 24 oral yeasts 62.5 % were positive for H. pylori 16S rDNA. From the 15 individuals positive for yeast harboring H. pylori, 81% of them reported stomach discomfort, and the presence of the bacteria was diagnosed at some moment in 20% of them.

CONCLUSION

The intracellular presence of the H. pylori in oral yeasts suggests an endosymbiotic relationship of these microorganisms, which could favor H. pylori transmission and reinfection in the gastrointestinal tract.

Helicobacter pylori Related Diseases and Osteoporotic Fractures (Narrative Review)

Osteoporosis (OP) and osteoporotic fractures (OFs) are common multifactorial and heterogenic disorders of increasing incidence. Helicobacter pylori (H.p.) colonizes the stomach approximately in half of the world's population, causes gastroduodenal diseases and is prevalent in numerous extra-digestive diseases known to be associated with OP/OF. The studies regarding relationship between H.p. infection (HPI) and OP/OFs are inconsistent. The current review summarizes the relevant literature on the potential role of HPI in OP, falls and OFs and highlights the reasons for controversies in the publications. In the first section, after a brief overview of HPI biological features, we analyze the studies evaluating the association of HPI and bone status. The second part includes data on the prevalence of OP/OFs in HPI-induced gastroduodenal diseases (peptic ulcer, chronic/atrophic gastritis and cancer) and the effects of acid-suppressive drugs. In the next section, we discuss the possible contribution of HPI-associated extra-digestive diseases and medications to OP/OF, focusing on conditions affecting both bone homeostasis and predisposing to falls. In the last section, we describe clinical implications of accumulated data on HPI as a co-factor of OP/OF and present a feasible five-step algorithm for OP/OF risk assessment and management in regard to HPI, emphasizing the importance of an integrative (but differentiated) holistic approach. Increased awareness about the consequences of HPI linked to OP/OF can aid early detection and management. Further research on the HPI-OP/OF relationship is needed to close current knowledge gaps and improve clinical management of both OP/OF and HPI-related disorders.

Relationship between Helicobacter pylori and Periodontal Diseases: A Meta-Analysis Study and Systematic Review

Objective:

The present study aimed at the evaluation of the association between H. pylori and periodontal diseases by systematic review and meta-analysis study.

Materials and Methods:

We searched databases, including PubMed, SID, Magiran, Google Scholar, and Iranmedex using the following keywords in English: H. pylori, tooth decay, oral infection, dental infection, gingival infection and periodontal diseases. Data was analyzed using a meta-analysis and random effect model. Heterogeneity of studies was assessed using the I2 index, and data was finally analyzed with STATA (Version 11.2).

Results:

Among 10 articles reviewed that included 56,334 samples, results showed that association between H. pylori and periodontal diseases was significant with OR (odds ratio) = 1.13 (95% CI: 1.04 to 1.24).

Conclusion:

The results reveal that H. pylori can be one of the main causes of periodontal diseases. Thus, a novel way should be employed for the complete management of H. pylori infections.

Phylogenetic analysis of clinical strains of Helicobacter pylori isolated from patients with gastric diseases in Tibet

BACKGROUND

Helicobacter pylori (H. pylori) is a Gram-negative pathogenic bacterium that causes chronic gastritis and other gastric diseases in humans. In Tibet, China, the infection of H. pylori is an important risk factor that caused gastric cancer.

METHODS

To understand the characteristics of this pathogen in Tibet, five strains of H. pylori were isolated from three patients' oral cavity or stomach who had either a gastric ulcer or gastritis. We performed genome sequences of these five clinical strains on Illumina Hiseq, and 55,016-63666 SNVs/InDels were identified by comparing to the reference strain of H. pylori 26995.

RESULTS

The phylogenetic analysis with multi-locus sequence typing (MLST) showed that five Tibetan strains were defined as hpEurope population and their proteins encoded by the cagA gene also presented a western type. Also, the strains that were isolated from the same patients' oral cavity and stomach exhibited homology in molecular evolution.

CONCLUSIONS

This is the first study to investigate the phylogenetic population structure of the epidemic strains of H. pylori in Tibet, which may improve cognition of Tibetan strains and confirm the homology of the strains from oral cavity and stomach.

Prevalence of Helicobacter pylori cagA and iceA Genes and Their Association with Gastrointestinal Diseases

H. pylori infection causes peptic ulcer, chronic gastritis, mucosa-associated lymphoid tissue lymphoma, and gastric carcinoma. It has several virulence factors such as cytotoxin-associated gene A(cagA) and the induced by contact with epithelium antigen (iceA). We aimed to explore the relationship between cagA and iceA of H. pylori and gastrointestinal diseases. One hundred and eighteen patients who attended Gastrointestinal Endoscopy Unit at Zagazig University Hospitals, Egypt, were included in this study. Two gastric biopsies were collected and evaluated by rapid urease test (RUT) and PCR. cagA and iceA genes were amplified by PCR. We found that 54 patients (45.76%) were positive by both RUT and PCR. cagA and iceA genes were present in 57.4% and 46.29% of the studied patients, respectively. cagA was the most prevalent gene in gastritis (33.3%) and peptic ulcer (68.7%). iceA1/iceA2 positive genes were the most prevalent in gastric cancer (75%). iceA1 gene was present in 38.7% of cagA positive cases, but iceA2 gene was present in 45.2% of cagA positive cases. iceA1/iceA2 positive genes were present in 29% of cagA positive cases. In conclusion, cagA and iceA genes could be used as markers for severe gastrointestinal diseases. iceA gene was strongly related to cagA gene.