Prevalence of Oral Helicobacter pylori Infection in an Indigenous Community in Southwest Mexico.

Purpose: Epidemiological studies have been conducted to improve the health and economic quality of life of indigenous communities in Mexico. These studies have found that infections cause frequent health problems. Helicobacter pylori are responsible for conditions ranging from gastritis to stomach cancer. This study determined the prevalence of H. pylori in families from Siltepec, Chiapas, Mexico. Patient and Methods: Ninety-nine dental plaque samples from 36 families were studied. Real-time PCR was performed to detect H. pylori using previously reported primers. The Mann-Whitney U-test was used for the statistical analysis. According to the family role of H. pylori-positive individuals, the VacA s1/m1 genotype and CagA gene correlated. Results: The mother had the highest expression of VacA s1/m1-/cagA- with 19% (8/42), followed by the first child with 14.3% (6/42). The major roles for the vacA s1/m1+/cagA- were the mother and first child with 9.5% (4/42), followed by the remaining children with 4.8% (2/42). The vacA s1/m1-/cagA+ genotype was 7.1% (3/42) for the mother and 4.8% (2/42) for the father. Finally, the vacA s1/m1+/cagA+ genotype only appeared in the mother, son I, and son III with 2.4% (1/42). Conclusion: The vacA s1/m1/cagA genotypes predominated in the mother, suggesting potential transmission between the mother and child during the first years of life.

Cytotoxicity of Peruvian propolis and Psidium guajava on human gingival fibroblasts, PBMCs and HeLa cells.

It is indisputable that every day it is demonstrated that natural products present diverse therapeutic benefits, which has boosted their incorporation within various products for clinical use. However, this must be accompanied by knowledge of their effect on cell lines to ensure their use is safe. The objective of this study was to evaluate the cytotoxic effect of two ethanolic extracts based on Peruvian natural products, on three human cell lines. Cervical cancer cell lines (HeLa), human gingival fibroblasts (HGF-1 - ATCC CRL-2014) (HGF-1) and peripheral blood mononuclear cells (PBMCs) were cultured and subsequently treated with preparations of ethanolic extracts of propolis (EEP) and Psidium guajava (EEG) from a concentration of 50 mg/mL to 0.024 mg/mL, by the 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazole bromide reduction assay. At a concentration of 0.24 mg/mL EEG, viability of 99.7±1.24%, 99.8±2.2% and 99.7±2.7% was observed in HeLa, HGF-1 and PBMCs, respectively; >90% cell viability values were observed with EPP at 0.024 mg/mL, with HGF-1 showing the highest viability (96.9±1.15%). A dose-dependent effect was observed for both extracts with a decrease in cell viability as concentrations increased (up to 50 mg/mL). EEP and EEG extracts at low concentrations do not show cytotoxicity in human cell lines, these findings are an advance in the preclinical evaluation on their safety and open a continuity to further studies for their potential applications in dentistry and medicine.

SSEA-4 positive dental pulp stem cells from deciduous teeth and their induction to neural precursor cells.

BACKGROUND: Stage-specific embryonic antigen-4 (SSEA-4) is a marker for the identification of multipotent embryonic cells. It is also positive in neuroepithelial cells, precursor neural cells (NPC), and human dental pulp cells. The aim of this study was to evaluate the potential morphodifferentiation and histodifferentiation to NPC of SSEA-4 positive stem cells from human exfoliated deciduous teeth (SHED). METHODS: A SHED population in culture, positive to SSEA-4, was obtained by magnetic cell separation. The cells were characterized by immunohistochemistry and flow cytometry. Subsequently, a neurosphere assay was performed in a medium supplemented with basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF); afterward, cells were neurodifferenciated with a neurobasal medium. Finally, indirect immunohistochemistry was performed to identify neuronal markers. RESULTS: The morphological and histological changes in the SSEA-4 positive SHEDs were observed after induction with epidermal and fibroblast growth factors in neurobasal culture medium. At the end of induction, the markers Nestin, TuJ-1, and GFAP were identified. CONCLUSIONS: The findings show that SSEA-4 positive SHEDs have a behavior similar to neuronal precursor cells. Our findings indicate that the dental pulp of deciduous teeth is a promising source for regeneration therapies associated with neurodegenerative diseases or peripheral nerve alterations.

Antibacterial efficacy of a pH-neutral electrolyzed super-oxidized solution for nonsurgical periodontal treatment.

Objective: Mouthwash is effective in maintaining oral hygiene in patients; however, there is concern that it may adversely affect human oral mucosa. We evaluated a pH-neutral electrolyzed super-oxidized solution (ESS, tradename OxOral®) combined with dental scaling in periodontitis patients. This longitudinal study was conducted with 34 patients divided into three groups. The control group treated with scaling plus saline, the second with scaling plus ESS mouthwash, and another with scaling plus ESS mouthwash and gel. The plaque index (PI), gingival index (GI), and probing depth (PD) were determined before and after periodontal treatment. Results: The final PI and GI decreased compared with the initial measurements in the three treatment groups (p < 0.05). Scaling plus ESS mouthwash and gel significantly reduced the final PI, GI, and DP compared to the control group (p < 0.05). Conclusion: Our study shows the antiseptic properties of ESS with mouthwash and gel. Further studies are needed to verify the results.

Antimicrobial Effect of Calcium Hydroxide Combined with Electrolyzed Superoxidized Solution at Neutral pH on Enterococcus faecalis Growth.

OBJECTIVE: To evaluate the effect of the combination of calcium hydroxide (Ca(OH)2) and a novel electrolyzed superoxidized solution at neutral pH, known as OxOral® on Enterococcus faecalis growth in root canals. METHODS: Sixty human teeth were used, from which root canals were infected and randomly divided into the following treatment groups: saline solution, saline solution plus Ca(OH)2, OxOral®, and OxOral® plus Ca(OH)2. RESULTS: A permanent reduction in bacterial growth was observed at days 1, 6, 12, and 18 after OxOral® plus Ca(OH)2 treatment from 4.4 ± 0.074 log10 CFU/mL to 0.0 ± 0.001 log10 CFU/mL. In addition, alkaline conditions maintenance was observed from application time (pH = 12.2 ± 0.033) to 18 d posttreatment (pH = 12.6 ± 0.083). CONCLUSION: The combination of OxOral® and Ca(OH)2 provides an alkaline pH and inhibits E. faecalis growth into the root canals. Our study opens the possibility for further research on the use of OxOral® in endodontic therapy.

Prevalence of human papillomavirus in the oral cavity of an indigenous community from Southwest México.

Human papilloma virus (HPV) is a DNA virus associated with the development of cervical, penile, anal, vulvar, and oral cancers. In recent years, there has been an increase in oral cancer, which could be due to changes in sexual behavior in the general population. In México, there is scarce information on this regard, which prompted us to study HPV infection prevalence in the oral cavity of an indigenous community from the municipality of Siltepec, Chiapas, Mexico. Oral samples from 198 individuals were obtained with cytobrush for virus detection by nested PCR, using MY09/MY11 and GP5+/GP6+ primers, and positive samples were sequenced for HPV genotyping. We observed 12.1% HPV infection prevalence, which depended on gender, number of sexual partners, lack of using condoms, and oral sex practices. In contrast, no significant association between HPV infection and tobacco or alcohol consumption was detected. Furthermore, sequencing analyzes were performed where HPV-13 (21/24), -16 (2/24), -32 (1/24), -81 (1/24), and -83 (1/24) were evidenced and HPV-16 European/Asian and Asian/American E6 variants identified. These results demonstrated an important prevalence of HPV infection in the oral cavity of a Mexican indigenous community, where the predominant genotypes were associated with benign pathologies, and showed that high-risk genotype variants derived from different lineages.

Molecular detection of Helicobacter pylori based on the presence of cagA and vacA virulence genes in dental plaque from patients with periodontitis.

BACKGROUND/PURPOSE: Helicobacter pylori (H. pylori) infection is the most common in the world and is associated with various gastrointestinal pathologies, including chronic gastritis, peptic ulcers, and gastric cancer. The prevalence is associated with socioeconomic conditions, with this infection being more common in developing countries than in developed countries. The presence and permanence of H. pylori in the oral cavity has been reported, but its role is controversial. The aim of this study was to determine the prevalence of H. pylori in dental plaque of patients with periodontitis. MATERIALS AND METHODS: A cross-sectional study was carried out and Periodontal Screening and Recording (PSR) index was determined. 38 dental plaque samples were taken and total DNA was extracted and qPCR was performed. RESULTS: 60.5% of the samples (n = 23) were positive for the presence of H. pylori by the amplification of the 16S rRNA and vacA genes. In addition, cagA gene was detected in 21.7% (n = 5) of H. pylori-positive. A significant relationship between periodontal status and H. pylori oral infection was found (P ≤ 0.05); patients with initial and moderate periodontitis were the most affected with 39.1% and 30.4%, respectively. CONCLUSION: Our results suggest that the prevalence of H. pylori in the oral cavity could be related to the progression of periodontal disease. Therefore, oral hygiene and treatment for the elimination of oral H. pylori could stop the progression of periodontal disease.

Immunoinformatics Approach to Design a Novel Epitope-Based Oral Vaccine Against Helicobacter pylori.

Helicobacter pylori is an infectious agent that colonizes the gastric mucosa of half of the population worldwide. This bacterium has been recognized as belonging to group 1 carcinogen by the World Health Organization for the role in development of gastritis, peptic ulcers, and cancer. Due to the increase in resistance to antibiotics used in the anti-H. pylori therapy, the development of an effective vaccine is an alternative of great interest, which remains a challenge. Therefore, a rational, strategic, and efficient vaccine design against H. pylori is necessary where the use of the most current bioinformatics tools could help achieve it. In this study, immunoinformatics approach was used to design a novel multiepitope oral vaccine against H. pylori. Our multiepitope vaccine is composed of cholera toxin subunit B (CTB) that is used as a mucosal adjuvant to enhance vaccine immunogenicity for oral immunization. CTB fused to 11 epitopes predicted of pathogenic (UreB170-189, VacA459-478, CagA1103-1122, GGT106-126, NapA30-44, and OipA211-230) and colonization (HpaA33-52, FlaA487-506, FecA437-456, BabA129-149, and SabA540-559) proteins from H. pylori. CKS9 peptide (CKSTHPLSC) targets epithelial microfold cells to enhance vaccine uptake from the gut barrier. All sequences were joined to each other by proper linkers. The vaccine was modeled and validated to achieve a high-quality three-dimensional structure. The vaccine design was evaluated as nonallergenic, antigenic, soluble, and with an appropriate molecular weight and isoelectric point. Our results suggest that our newly designed vaccine could serve as a promising anti-H. pylori vaccine candidate.

Antimicrobial and Anti-Biofilm Effect of an Electrolyzed Superoxidized Solution at Neutral-pH against Helicobacter pylori.

The presence of Helicobacter pylori in the oral cavity has been associated to the failure of antimicrobial therapy in patients with gastrointestinal infection and the development of oral diseases. However, it has been reported that the maintenance of good oral hygiene can improve the therapeutic success rates, where the use of mouthwashes with anti-Helicobacter activity would help to achieve it. The aim was to evaluate the antimicrobial activity of OxOral® mouthwash against H. pylori and its effect on biofilm formation. The minimum inhibitory concentration (MIC) of OxOral® (pH = 6.4-7.5, ORP = 650-900 mV) against H. pylori was calculated testing serial dilutions 0.117-15 ppm against 1 × 108 CFU/mL of H. pylori (ATCC® 700824™) by broth microdilution method using 96-well plates. The H. pylori biofilm formation was determined by the optical density measurement at 600 nm from coverslips stained with 0.1% crystal violet. The gene expression of ureA, luxS, flaA, omp18, and lpxD were analyzed by RT-qPCR. OxOral® cytotoxicity was evaluated in a human gingival fibroblast cell line by MTT assay. MIC was of 3.75 ppm, with 99.7 ± 7.7% bacterial growth inhibition. In the negative control, the biofilm formation was observed, whereas when bacteria were treated with OxOral® at 0.234, 0.469, and 0.938 ppm, an inhibition of 35.5 ± 0.9%, 89.1 ± 1.2%, and 99.9 ± 5.5% were obtained, respectively. The gene expression analysis showed that flaA, omp18, and lpxD genes were down-regulated with OxOral® compared with control (p < 0.05). Low cytotoxicity of 16.5 ± 7.6% was observed at the highest dose (15 ppm); no significant differences were observed from 15 to 0.469 ppm compared to the control of untreated cells (p > 0.05). Our results reveal an important anti-Helicobacter activity of OxOral® and open the possibility of its therapeutic use new studies, which would increase the success rate of conventional therapies against H. pylori.

In Vitro Antimicrobial Activity and Downregulation of Virulence Gene Expression on Helicobacter pylori by Reuterin.

Helicobacter pylori is an infectious agent commonly associated with gastrointestinal diseases. The use of probiotics to treat this infection has been documented, however, their potential antimicrobial metabolites have not yet been investigated. In the present study, the effect of reuterin produced by Lactobacillus reuteri on H. pylori growth and virulence gene expression was evaluated. It was observed that reuterin caused significant (P < 0.05) H. pylori growth inhibition at concentrations from 0.08 to 20.48 mM, with minimal inhibitory concentrations (MICs) of 20.48 mM for H. pylori ATCC700824 and 10.24 mM for H. pylori ATCC43504. In a reuterin bacterial killing assay, it was observed that half of the MIC value for H. pylori (ATCC700824) significantly (P < 0.01) reduced colony numbers from 5.65 ± 0.35 to 3.78 ± 0.35 Log10 CFU/mL after 12 h of treatment and then increased them to 5.25 ± 0.23 Log10 CFU/mL at 24 h; at its MIC value (20.48 mM), reuterin abrogated (P < 0.01) H. pylori (ATCC700824) growth after 20 h of culture. In addition, reuterin significantly (P < 0.01) reduced H. pylori (ATCC 43504) colony numbers from 5.65 ± 0.35 to 4.1 ± 0.12 Log10 CFU/mL from 12 to 24 h of treatment and abrogated its growth at its MIC value (10.24 mM), after 20 h of treatment. Reuterin did not alter normal human gastric Hs738.St/Int cell viability at the concentrations tested for H. pylori strains. Furthermore, 10 µM reuterin was shown to significantly (P < 0.01) reduce mRNA relative expression levels of H. pylori virulence genes vacA and flaA at 3 h post-treatment, whose effect was higher at 6 h post-treatment, as measured by RT-qPCR. The observed direct antimicrobial effect and the downregulation of expression of virulence genes on H. pylori by reuterin may contribute to the understanding of the mechanisms of action of probiotics against H. pylori.

Prevalence of Helicobacter pylori vacA Genotypes and cagA Gene in Dental Plaque of Asymptomatic Mexican Children.

The variability in Helicobacter pylori vacA and cagA genes has been related to the progression of the gastrointestinal disease; also the presence of H. pylori in the oral cavity has been associated with periodontal disease in adults, but, in children without dyspeptic symptoms, little is known about this. We evaluated the prevalence of H. pylori and the presence of vacA/cagA genotypes in the oral cavity of Mexican children without dyspeptic symptoms. The gingival status was measured, and dental plaque samples (n = 100) were taken. 38% of children were positive for H. pylori 16S rRNA gene by qPCR. A significant association between H. pylori oral infection and gingival status was observed (P < 0.001). In 34.6% (9/26) of mild gingivitis cases, s1m2 genotype was found, while s1m1 was typed in 50% (3/6) of moderate gingivitis. The cagA prevalence among H. pylori-positive children was 80.8% (21/26), 83.3% (5/6), and 16.7% (1/6) of cases of mild gingivitis, moderate gingivitis, and nongingivitis, respectively (P < 0.001). The s1m1/cagA+ combinational genotype was the most detected in children with gingivitis. Our results suggest that the prevalence of H. pylori and detection of vacA/cagA genotypes-associated gastrointestinal disease in the oral cavity could be related to the progression of gingivitis in asymptomatic children.