Future Nanotechnology-Based Strategies for Improved Management of Helicobacter pylori Infection.

Helicobacter pylori (H. pylori) is a recalcitrant pathogen, which can cause gastric disorders. During the past decades, polypharmacy-based regimens, such as triple and quadruple therapies have been widely used against H. pylori. However, polyantibiotic therapies can disturb the host gastric/gut microbiota and lead to antibiotic resistance. Thus, simpler but more effective approaches should be developed. Here, some recent advances in nanostructured drug delivery systems to treat H. pylori infection are summarized. Also, for the first time, a drug release paradigm is proposed to prevent H. pylori antibiotic resistance along with an IVIVC model in order to connect the drug release profile with a reduction in bacterial colony counts. Then, local delivery systems including mucoadhesive, mucopenetrating, and cytoadhesive nanobiomaterials are discussed in the battle against H. pylori infection. Afterward, engineered delivery platforms including polymer-coated nanoemulsions and polymer-coated nanoliposomes are poposed. These bioinspired platforms can contain an antimicrobial agent enclosed within smart multifunctional nanoformulations. These bioplatforms can prevent the development of antibiotic resistance, as well as specifically killing H. pylori with no or only slight negative effects on the host gastrointestinal microbiota. Finally, the essential checkpoints that should be passed to confirm the potential effectiveness of anti-H. pylori nanosystems are discussed.

Gastric bacteria as potential biomarkers for the diagnosis of atrophic gastritis.

BACKGROUND: Identification of the risk factors for atrophic gastritis (AG) and prevention of further deterioration of the gastritis are effective approaches to reduce the incidence of gastric cancer. Previous studies found that dysbiosis has been implicated in a wide range of diseases, while the role of gastric bacteria as a biomarker for AG has not been explored. METHODS AND RESULTS: Gastric juices from cases with non-atrophic gastritis (NAG) and AG were collected for investigation of bacterial composition and function. The ß-diversity of microbiota exhibited a significant reduction in AG samples compared with that in NAG samples. Differential abundance analysis revealed that a total of 23 predicted species changed their distributions; meanwhile, all obligate anaerobic bacteria with a relatively high abundance lowered their contents in AG samples. Additionally, the correlation analysis indicated a clear shift in bacterial correlation pattern between the two groups. Functional interrogation of the gastric microbiota showed that bacterial metabolisms associated with enzyme families, digestive system, and endocrine system were downregulated in AG samples. The compositional dissection of "core microbiota" exhibited that oral pathogens, including Porphyromonas gingivalis, Campylobacter gracilis, and Granulicatella elegans, were magnified in AG samples, suggesting that oral diseases may be a trigger factor for early exacerbation of gastritis. Then, the differentially expressed bacteria were used as diagnostic biomarkers for the random forest classifier model for group prediction. CONCLUSIONS: The results showed that bacterial biomarkers could distinguish AG patients from NAG cases with an accuracy of 90% at the genus level.

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.

Helicobacter pylori infection is correlated with the incidence of erosive oral lichen planus and the alteration of the oral microbiome composition.

BACKGROUND: Oral lichen planus (OLP), a common clinical oral disease, is associated with an increased risk of malignant transformation. The mechanism underlying the pathogenesis of OLP is unknown. Oral dysbacteriosis is reported to be one of the aetiological factors of OLP. Although Helicobacter pylori infection is associated with various oral diseases, the correlation between H. pylori infection and OLP is unclear. This study aimed to investigate the effect of H. pylori infection on OLP pathogenesis and oral microbiome composition in the Chinese population, which has a high incidence of H. pylori infection. RESULT: In this study, saliva samples of 30 patients with OLP (OLP group) and 21 negative controls (NC group) were collected. H. pylori infection was detected using the carbon-13-labeled urea breath test (UBT). The saliva samples were divided into the following four groups based on the H. pylori status: H. pylori-positive OLP (OLP+), H. pylori-positive NC (NC+), H. pylori-negative OLP (OLP-), and H. pylori-negative NC (NC-). Oral microbiome compositions were significantly different between the OLP and NC groups and between the OLP- and OLP+ groups. Compared with those in the OLP- group, those in the OLP+ group had a higher incidence of erosive OLP and higher levels of salivary cytokines. In contrast, the oral microbiome composition and cytokine levels were not significantly different between the NC- and NC+ groups. CONCLUSIONS: This is the first report to demonstrate that H. pylori infection is significantly correlated with the pathogenesis of erosive OLP.

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.

The relationship between the simultaneity present of cagA and hopQI genes in Helicobacter pylori and the risk of gastric cancer.

Helicobacter pylori is a bacterium that causes infections in the gastrointestinal tract. This type of bacterium is very common and contagious at the same time. H. pylori enters the mouth and continues its course along the gastrointestinal tract. H. pylori infection induces an inflammatory response that leads to the activity of neutrophils, lymphocytes, plasma cells, and macrophages. In addition to the bacterial role in gastric mucosa, the host's inflammatory response may also play a role in disease outcome. In inflammation, the risk of carcinogenesis increases due to DNA damage increased proliferation and the creation of an environment rich in cytokines and growth factors. Genetic methods and diagnosis of H. pylori genes are used to identify healthy and healthy gastric cancer patients infected with H. pylori. In relation to the genes associated with H. pylori pathogenesis, the presence of genes such as cagA, hopQI, hopQII and so on is used, and PCR of a part of these genes amplified fragments of different lengths. One of the less-studied cases is the association of two or more pathogenic genes simultaneously with H. pylori. In this research, the frequency of disease and healthy individuals who are infected with H. pylori and have two genotypes cagA and hopQI at the same time, was examined. In order to diagnose H. pylori-infected individuals in healthy and gastric cancer patients, after PCR of glmM gene, PCR product electrophoresis on agarose gel was used. For this purpose, gastric tissue biopsy was used in patients and saliva was used in healthy individuals. For this purpose, 100 gastric biopsy samples were collected from patients with gastric cancer and 100 saliva samples from healthy individuals. According to the data, there is a significant relationship between the simultaneous presence of two genes cagA and hopQI and gastric cancer. In patients, 45.3% showed both genotypes, while in healthy individuals only 10.5% have this genotype and other healthy but infected with H. pylori (90.8%) do not have this genotype. To be. No report was observed on the simultaneous study of cagA and hopQI genes. No report was observed regarding the simultaneous study of cagA and hopQI genes.

Oral rinses in growth inhibition and treatment of Helicobacter pylori infection.

BACKGROUND: Helicobacter pylori (H. pylori) is well-known for its role in chronic gastritis and gastric cancer. Eradication of these carcinogenic bacteria from the gut is one of the challenges for clinicians. The complexity of treatment mainly owes to antibiotic resistance and relapse due to an additional reservoir in the oral cavity. Our study emphases the isolation of H. pylori from distinct habitats of the gut microenvironment (gastric biopsy and gastric juice) and its subsequent characterization. We have also evaluated the effect of various oral rinses on isolated H. pylori from different anatomical locations of included subjects. RESULTS: The possible strains isolated from two different habitats of the same subject shows a striking difference in their growth pattern. Promisingly, some of the included oral rinses are efficient in growth inhibition as per recommended 30 s treatment. The subsequent evaluation shows that oral rinse B (among A-E) is most effective and down-regulates the expression of one of the potent H. pylori gene, CagA, in the infected gastric adenocarcinoma (AGS) cells. CONCLUSION: Our study, for the first time, revealed that H. pylori, isolated from the different habitat of the same subject, show a different growth pattern. The expression of H. pylori pathogenic gene (CagA) was down-regulated by the use of oral rinses. Hence, oral rinses will reduce the H. pylori in the oral cavity and help to control its migration from oral to the gastric compartment and may be used as an adjuvant treatment option for its re-infection.

New Silver(I) Coordination Compound Loaded into Polymeric Nanoparticles as a Strategy to Improve In Vitro Anti-Helicobacter pylori Activity.

Helicobacter pylori inhabits the gastric epithelium and can promote the development of gastric disorders, such as peptic ulcers, acute and chronic gastritis, mucosal lymphoid tissue (MALT), and gastric adenocarcinomas. To use nanotechnology as a tool to increase the antibacterial activity of silver I [Ag(I)] compounds, this study suggests a new strategy for H. pylori infections, which have hitherto been difficult to control. [Ag (PhTSC·HCl)2] (NO3)·H2O (compound 1) was synthesized, characterized, and loaded into polymeric nanoparticles (PN1). PN1 had been developed by nanoprecipitation with poly(ε-caprolactone) polymer and poloxamer 407 surfactant. System characterization assays showed that the PNs had adequate particle sizes and ζ-potentials. Transmission electron microscopy confirmed the formation of polymeric nanoparticles (PNs). Compound 1 had a minimum inhibitory concentration for H. pylori of 3.90 µg/mL, which was potentiated to 0.781 µg/mL after loading. The minimum bactericidal concentration of 7.81 µg/mL was potentiated 5-fold to 1.56 µg/mL in PN. Compound 1 loaded in PN1 displayed better activity for H. pylori biofilm formation and mature biofilm. PN1 reduced the toxicity of compound 1 to MRC-5 cells. Loading compound 1 into PN1 inhibited the mutagenicity of the free compound. In vivo, the system allowed survival of Galleria mellonella larvae at a concentration of 200 µg/mL. This is the first demonstration of the antibacterial activity of a silver complex enclosed in polymeric nanoparticles against H. pylori.

Molecular epidemiologic and clinical analysis of Helicobacter cinaedi bacteremia in Japan.

BACKGROUND: Helicobacter cinaedi is an important pathogen that causes bloodstream infections. Owing to the challenges in its culture and identification, its clinical and bacterial characteristics remain unknown. Our study aimed to investigate the molecular epidemiology and antimicrobial susceptibility of H cinaedi. MATERIALS AND METHODS: From 2003 to 2016, we analyzed 16 non-repetitive H cinaedi strains, isolated from blood, at the medical hospital of Tokyo Medical and Dental University. Multilocus sequence typing was performed to analyze the genetic relationship across the different isolates. The minimum inhibitory concentrations (MIC) of antibiotics were determined by the agar dilution method. RESULTS: The median age of subjects in this study was 61 years (range, 18-84 years). The most common risk factors included the use of steroids (75.0%) and immunosuppressant drugs (37.5%). In addition, the most common symptoms of H cinaedi bacteremia included colitis (37.5%) and cellulitis (31.3%). The infection recurred in three of seven cases (42.8%) that underwent antibiotic therapy for <10 days. The strains were classified into five sequence types (ST), of which, ST 10 (43.8%) and ST 4 (31.3%) were predominant. The MIC90 values of amoxicillin, gentamycin, imipenem, ciprofloxacin, and clarithromycin were 4, 0.5, 0.25, 64, and 128 mg/L, respectively. CONCLUSIONS: Since there is no recommended guideline yet for the choice or duration of antibiotic therapy and antimicrobial break points, our results suggested, for the first time, that prolonged antibiotic therapy, except with ciprofloxacin and clarithromycin, would be required to ensure resolution of symptoms and prevention of recurrence.

Analysis of by high-throughput sequencing: Helicobacter pylori infection and salivary microbiome.

BACKGROUND: There have been reports of Helicobacter pylori (H. pylori) in the oral cavity and it has been suggested that the oral cavity may be a reservoir for H. pylori reflux from the stomach. High-throughput sequencing was used to assess the structure and composition of oral microbiota communities in individuals with or without confirmed H. pylori infection. METHODS: Saliva samples were obtained from 34 H. pylori infected and 24 H. pylori uninfected subjects. Bacterial genomic DNA was extracted and examined by sequencing by amplification of the 16S rDNA V3-V4 hypervariable regions followed by bioinformatics analysis. Saliva sampling was repeated from 22 of the 34 H. pylori infected subjects 2 months after H. pylori eradication. RESULTS: High-quality sequences (2,812,659) clustered into 95,812 operational taxonomic units (OTUs; 97% identity). H. pylori was detected in the oral cavity in infected (12/34), uninfected (11/24) and eradicated (15/22) subjects by technique of high-throughput sequencing, occupying 0.0139% of the total sequences. Alpha diversity of H. pylori infected subjects was similar to that of uninfected subjects (Shannon: 1417.58 vs. 1393.60, p > 0.05, ACE: 1491.22 vs. 1465.97, p > 0.05, Chao 1: 1417.58 vs. 1393.60, p > 0.05, t-test). Eradication treatment decreased salivary bacterial diversity (Shannon, p = 0.015, ACE, p = 0.003, Chao 1, p = 0.002, t-test). Beta diversity analysis based on unweighted UniFrac distances showed that the salivary microbial community structure differed between H. pylori infected and uninfected subjects (PERMANOVAR, pseudo-F: 1.49, p = 0.033), as well as before and after H. pylori eradication (PERMANOVAR, pseudo-F: 3.34, p = 0.001). Using LEfSe analysis, 16 differentially abundant genera were defined between infected and uninfected subjects, 12 of which had a further alteration after successful eradication. CONCLUSIONS: Our study using high-throughput sequencing showed that H. pylori was present commonly in the oral cavity with no clear relation to H. pylori infection of the stomach. Both H. pylori infection and eradication therapy caused alterations in community and structure of the oral microbiota. TRIAL REGISTRATION: clinicaltrials.gov, NCT03730766. Registered 2 Nov 2018 - Retrospectively registered, https://clinicaltrials.gov/ct2/show/ NCT03730766.

Halitosis: Helicobacter pylori or oral factors.

INTRODUCTION: Halitosis is a common complaint among people which has various socioeconomic effects. The prevalence of halitosis includes a variety of 22% up to 50% in different societies. According to studies, there have been reports of remarkable improvements in halitosis after Helicobacter pylori eradication treatment. In studies on the relationship between H. Pylori and halitosis, the role of oral factors as the most important cause of halitosis has been neglected. This study was conducted with the aim of investigating the effect of oral factors on halitosis in patients with H. Pylori. MATERIALS AND METHODS: A total of 100 dyspeptic patients who had H. pylori-positive serologic test were examined by an organoleptic method for the presence of halitosis. DMFT index was used in order to record the dental status. Oral hygiene was evaluated using the simplified oral hygiene index (OHI-S). RESULTS: The mean DMFT index was 9.09 ± 3.97. The score of simplified oral hygiene index was 1.79 ± 0.949. There was a direct and significant relationship between halitosis with DMFT, OHI-S (P < 0.01). There was no significant relationship between halitosis and coated tongue (P > 0.01). CONCLUSIONS: According to the results of this study, there is a relation between oral factors and halitosis in patients with positive H. pylori test. Due to the lower level of all these indices in patients with halitosis, we cannot attribute halitosis in patients with H. pylori infection to the presence of this microorganism with certainty.

Bismuth, rabeprazole, amoxicillin, and doxycycline as first-line Helicobacter pylori therapy in clinical practice: A pilot study.

BACKGROUND: Bismuth-containing quadruple therapy (BQT) is a recommended alternative first-line therapy for Helicobacter pylori (H. pylori) infection. We aim to evaluate the efficacy and safety of a new BQT with amoxicillin and doxycycline as a first-line treatment for H. pylori infection in clinical practice. METHODS: An open, prospective pilot clinical study including H. pylori-positive outpatients who had never received eradication treatment was carried out. An RADB regimen (10 mg rabeprazole, 1000 mg amoxicillin, 100 mg doxycycline, and 220 mg colloidal bismuth tartrate, all given bid for 14 days) was prescribed by gastroenterologists. H. pylori eradication was confirmed by a 13 C-urea breath test performed at least 6 weeks after the end of treatment. Regimen efficacy was evaluated by per-protocol (PP) and intention-to-treat (ITT) analyses. RESULTS: One hundred eighteen patients were included in the study. The eradication rate of RADB was 93.8% (105/112; 95% CI 89.2%-98.3%) in PP analysis and 89.8% (106/118; 95% CI 84.3%-95.4%) in ITT analysis. The patient compliance rate was 97.5% (115/118). The adverse event rate was 6.8% (8/118). Adverse events included asthenia, loss of appetite, dry mouth, heartburn, diarrhea, and abdominal pain. All adverse events disappeared after completion of therapy. CONCLUSION: Our results suggest that 14-day BQT with amoxicillin and doxycycline can be an effective and safe eradication regimen for first-line therapy against H. pylori infection in clinical practice.

The active bacterial assemblages of the upper GI tract in individuals with and without Helicobacter infection.

OBJECTIVE: Patients infected with Helicobacter pylori develop chronic gastritis with a subgroup progressing to further complications. The role of microbiota from the oral cavity swallowed with saliva and either transiting the stomach or persisting in the gastric mucosa is uncertain. It is also not known whether the bacterial community differs in luminal and mucosal niches. A key question is whether H. pylori influences the bacterial communities of gastroduodenal niches. DESIGN: Saliva, gastric and duodenal aspirates as well as gastric and duodenal biopsies were collected during oesophagogastroduodenoscopy from 24 patients (m:9, f:15, mean age 52.2±SD 14.5 years). RNA was extracted and the V1-V2 region of the retrotranscribed bacterial 16S rRNA amplified and sequenced on the Illumina MiSeq platform. RESULTS: Overall, 687 bacterial phylotypes that belonged to 95 genera and 11 phyla were observed. Each individual comprised a unique microbiota composition that was consistent across the different niches. However, the stomach fluid enriched for specific microbiota components. Helicobacter spp were shown to dominate the mucosa-associated community in the stomach, and to significantly influence duodenal and oral communities. CONCLUSIONS: The detailed analysis of the active global bacterial communities from the five distinct sites of the upper GI tract allowed for the first time the differentiation between host effects and the influence of sampling region on the bacterial community. The influence of Helicobacter spp on the global community structures is striking.

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

BACKGROUND: Two-thirds of the world's population is thought to be infected by Helicobacter pylori. Although most people infected with H. pylori are asymptomatic, this pathogen is associated with several gastric pathologies including cancer. The risk factors for colonization are still unclear and the genetic diversity within individual hosts has never been clearly investigated. RESULT: This study determined the prevalence of, and explored risk factors for, H. pylori infection directly from paired saliva (n = 110) and stool (n = 110) samples from asymptomatic persons in Northeast Thailand. Samples were subjected to indirect immunofluorescence assay (IFA), 16S rRNA-based real-time PCR and vacA-based semi-nested PCR. Partial vacA gene sequences of H. pylori were compared between saliva and stool samples. The overall prevalence of H. pylori infection in our asymptomatic study population was 64%. Age, gender, occupation and frequency of brushing teeth were not found to be associated with H. pylori colonization. The vacA gene was successfully sequenced from both saliva and stool samples of 12 individuals. For seven of these individuals, saliva and stool sequences fell into different clusters on a phylogenetic tree, indicating intra-host genetic variation of H. pylori. CONCLUSION: This study reports a high prevalence of H. pylori infection in asymptomatic persons in this region of Thailand and demonstrates that genotypes (vacA gene sequences) of H. pylori may differ between the oral cavity and intestinal tract.

Impact of the Microbiota and Gastric Disease Development by Helicobacter pylori.

Microorganisms in humans form complex communities with important functions and differences in each part of the body. The stomach was considered to be a sterile organ until the discovery of Helicobacter pylori, but nowadays, it is possible to demonstrate that other microorganisms beyond H. pylori can colonize the gastric mucosa and that the diverse microbiota ecosystem of the stomach is different from the mouth and the esophagus, and also from the small intestine and large intestine. H. pylori seems to be the most important member of the gastric microbiota with the highest relative abundance when present, but when it is absent, the stomach has a diverse microbiota. Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes, and Fusobacteria are the most abundant phyla in both H. pylori-positive and H. pylori-negative patients. The gastric commensal flora may play some role in the H. pylori-associated carcinogenicity, and differences in the gastric microbiota composition of patients with gastric cancer, intestinal metaplasia, and chronic gastritis are described. The gastric microbiota changed gradually from non-atrophic gastritis to intestinal metaplasia, and to gastric cancer (type intestinal).

Promoting Immune Efficacy of the Oral Helicobacter pylori Vaccine by HP55/PBCA Nanoparticles against the Gastrointestinal Environment.

The immunogenicity of oral subunit vaccines is poor partly as a result of the harsh milieu of the gastrointestinal (GI) tract. For some pathogens that restrictedly inhabit the GI tract, a vaccine that works in situ may provide more potent protection than vaccines that operate parenterally. Yet, no appropriate delivery system is available for oral subunit vaccines. In this study, we designed HP55/poly( n-butylcyanoacrylate) (PBCA) nanoparticles (NPs) to carry Helicobacter pylori ( H. pylori) subunit vaccine CCF for oral administration in a prophylactic mice model. These NPs, which are synthesized using an interfacial polymerization method, protected the CCF antigen not only from the acidic pH in simulated gastric fluid (SGF, pH 1.2) but also from the proteolysis in simulated intestinal fluid (SIF, pH 7.4). Oral vaccination of mice with HP55/PBCA-CCF NPs promoted the production of serum antigen-specific antibodies, mucosal secretory IgA, and proinflammatory cytokines. Moreover, a Th1/Th17 response and augmented lymphocytes were found in the gastric tissue of HP55/PBCA-CCF NP-immunized mice, which might eventually limit H. pylori colonization. Collectively, these results indicate that HP55/PBCA NPs are promising carriers against the severe situation of the GI tract and thereby may be further utilized for other orally administrated vaccines or drugs.

Molecular and clinical analyses of Helicobacter pylori colonization in inflamed dental pulp.

BACKGROUND: Recently, dental pulp has been considered a possible source of infection of Helicobacter pylori (H. pylori) in children. We previously developed a novel PCR system for H. pylori detection with high specificity and sensitivity using primer sets constructed based on the complete genome information for 48 H. pylori strains. This PCR system showed high sensitivity with a detection limit of 1-10 cells when serial dilutions of H. pylori genomic DNA were used as templates. However, the detection limit was lower (102-103 cells) when H. pylori bacterial DNA was detected from inflamed pulp specimens. Thus, we further refined the system using a nested PCR method, which was much more sensitive than the previous single PCR method. In addition, we examined the distribution and virulence of H. pylori in inflamed pulp tissue. METHODS: Nested PCR system was constructed using primer sets designed from the complete genome information of 48 H. pylori strains. The detection limit of the nested PCR system was 1-10 cells using both H. pylori genomic DNA and bacterial DNA isolated from inflamed pulp specimens. Next, distribution of H. pylori was examined using 131 inflamed pulp specimens with the nested PCR system. In addition, association between the detection of H. pylori and clinical information regarding endodontic-infected teeth were investigated. Furthermore, adhesion property of H. pylori strains to human dental fibroblast cells was examined. RESULTS: H. pylori was present in 38.9% of inflamed pulp specimens using the nested PCR system. H. pylori was shown to be predominantly detected in primary teeth rather than permanent teeth. In addition, samplings of the inflamed pulp were performed twice from the same teeth at 1- or 2-week intervals, which revealed that H. pylori was detected in most specimens in both samplings. Furthermore, H. pylori strains showed adhesion property to human dental fibroblast cells. CONCLUSION: Our results suggest that H. pylori colonizes inflamed pulp in approximately 40% of all cases through adhesion to human dental fibroblast cells.

Helicobacter pylori in periodontal pockets and saliva: a possible role in gastric infection relapses.

It has been a long time since the scientific community started to speculate upon the presence of Helicobacter pylori (HP) in periodontal pockets as an extra-gastric reservoir responsible for gastric relapses after eradication therapy. The aim of this study is to evaluate the presence of oral HP in a group of patients who underwent examination for gastric infection. Sixty patients were enrolled in the current study, subdivided into two groups: 30 patients with a positive result for HP gastric infection with C-Breath Test Urea examination, and 30 patients with a negative result for HP gastric infection. Crevicular fluid and salivary samples were collected in a sterile tube and then sent to the laboratory for evaluation. Specimens were processed to quantify the levels of HP and bacterial load by real time PCR technique. Even though there was no statistically significant difference among the two groups (A vs B) with regard to the total amount of HP in saliva or in periodontal tissues, this study demonstrates that the oral cavity is an extra-gastric reservoir of HP when it is affected by periodontal disease, and that periodontal disease is correlated to gastric HP infection.

An evaluation of the usefulness of invasive and non-invasive methods used to diagnose Helicobacter spp. infections in dogs.

The aim of this study was to assess the suitability of invasive and non-invasive methods used to diagnose Helicobacter spp. in the stomachs of dogs. The study was carried out on 30 dogs of both sexes and different breeds, between one and 15 years old. A histopathologic examination, a microbiological culture, a rapid urease test, a direct bacteriological preparation and a nested PCR assay were carried out. Gastric Helicobacter spp. was identified in gastric biopsy specimens from 16 (53.3%) dogs using direct bacteriological preparation, in four (13.3%) dogs based on a culture, in 23 (76.6%) dogs using the rapid urease test and in 21 (70,0%) dogs based on a histopathological assessment of the biopsy specimens. The nested PCR of the gastric biopsy specimens revealed gastric Helicobacter spp. in all the dogs (100%). A saliva PCR assay revealed gastric Helicobacter spp. in 23 (76.6%) dogs, while stool PCR revealed the bacterium in seven (23.3%) dogs. We found that invasive methods were more accurate than non-invasive methods in detecting a Helicobacter spp. infection in dogs. In addition, the nested PCR method used to evaluate the gastric mucosal biopsy specimens was the most accurate test for detecting Helicobacter spp. It was further found that the PCR-based saliva assay was the best non-invasive method for detecting Helicobacter spp. However, taking into consideration that most of the diagnostic methods used to detect this bacterium have drawbacks, at least two diagnostic methods should be used to detect Helicobacter spp. as is done in human medicine.