Prevalence and virulence factors of Helicobacter pylori isolated from oral cavity of non-disease, gastritis, and gastric cancer patients.

Background/purpose: The oral cavity is considered a reservoir of Helicobacter pylori associated with gastric infection. It aimed to examine the prevalence of H. pylori strains from the oral cavity and gastric tissue of patients with different stage of gastric-diseases. Strains were further characterized for virulence genes, adhesion ability, and inflammation responses. Materials and methods: 11 non-disease, 15 gastritis, and 15 gastric cancer participated in the study. After clinical examination, gastric biopsies, saliva and plaque samples were collected and H. pylori levels were examined by real-time PCR and cultivation. The cagA and vacA genes were investigated from the culture strains. Adhesion ability and pro-inflammatory responses were analyzed in comparison between the presence of virulent genes and disease status. Results: Relatively poor periodontal condition was found among gastric cancer patients. Prevalence of H. pylori-positive was 84.8% and 19.5% by real-time PCR and cultivation, respectively. The cagA and vacA gene-positive strains were 52.6% and 5.3%, respectively, which were found more in gastric cancer patients. The cagA gene-positive strains were found to be higher in gastric cancer patients, and strains had significantly higher adhesion ability and pro-inflammation expressions than the cagA gene-negative strains. Conclusion: Colonization by H. pylori in oral cavity was confirmed, and the cagA gene-positive strains play a crucial role in both adhesion and inflammatory responses. The presence of H. pylori and its virulence gene in oral cavity should be received attention. An eradication of such strains from oral cavity may help to prevent the transmission and recolonization to gastric organs.

Characterization of adhesion, anti-adhesion, co-aggregation, and hydrophobicity of Helicobacter pylori and probiotic strains.

Objectives: To characterize the adhesion ability of nine Helicobacter pylori strains and eight probiotics in human oral keratinocyte cells (H357 cells) in comparison to intestinal cells (Caco-2 and HIEC-6 cells). Subsequently, the anti-adhesion and co-aggregation abilities of the selected probiotic strains on H. pylori strains were investigated. Methods: Nine H. pylori strains, including H. pylori ATCC43504 (type strain), and 8 clinical strains, were isolated from oral samples of three patients (one non-disease, one gastritis patient, and one gastric cancer patient). Eight selected probiotic strains were used, as follows: Lacticaseibacillus paracasei SD1, Lacticaseibacillus rhamnosus SD4, L. rhamnosus SD11, Limosilactobacillus fermentum SD7, L. rhamnosus GG, Limosilactobacillus reuteri ATCC-PTA6475, Lacticaseibacillus casei Shirota, and L. paracasei CNCM I-1572. The adhesion and anti-adhesion abilities of H. pylori and the probiotic strains were investigated in H357, Caco-2, and HIEC-6 cells. Co-aggregation at various pHs, hydrophobicity, and surface receptors of the cell lines for H. pylori strains were examined. Results: All probiotic and H. pylori strains adhered to H357 significantly better than Caco-2, and HIEC-6 cells. Three probiotic strains (SD7, SD4, SD11) showed significantly higher adhesion than others. Of the clinical H. pylori strains, isolates from a gastric cancer patient had the highest adhesion ability to all of the cell lines tested. Probiotic strains that exhibited high adhesion ability provided high anti-adhesion and co-aggregation against H. pylori strains. Acidic conditions encouraged the co-aggregation of probiotics to H. pylori strains. Conclusion: This study provides information relating to the adhesion abilities of clinical H. pylori and probiotic strains to the oral mucosa when compared to the intestinal mucosa. Certain probiotic strains may be useful for the successful eradication of H. pylori infection via anti-adhesion and co-aggregation.

Virulence of Aggregatibacter actinomycetemcomitans serotypes and DGGE subtypes isolated from chronic adult periodontitis in Thailand.

A high proportion of non-serotypeable isolates of Aggregatibacter actinomycetemcomitans among Thai periodontitis cases has been previously reported. The aim of this study was to investigate the expression of leukotoxin and toxicity, cytolethal distending toxin (Cdts), and internalization and the killing effect on fibroblasts by A. actinomycetemcomitans subtypes from Thai chronic periodontitis cases. A total of 96 A. actinomycetemcomitans strains from 37 periodontitis cases, previously serotyped with PCR and subtyped with DGGE, were examined for the presence of the ltx gene and cdt genes (cdtBC), and tested for leukotoxin expression, leukotoxicity, internalization, and apoptosis of fibroblast cells. The ltx gene was present in all isolates, while 84.4% showed the cdtBC gene. Two strains with a JP2-like ltx gene with a deletion of 530 bp in the promoter region, serotyped as c, showed virulence of similar magnitude to the JP2 strain. Furthermore, a higher virulence was found in the two non-serotypeable DGGE subtypes, NS1 and NS2, compared with the serotypeable strains (serotype a-f, serotype b and d were absent). Generally, the virulence of strains obtained from deep periodontal pockets was higher than those isolated from shallow non-bleeding pockets. A. actinomycetemcomitans subtypes isolated from adult Thais with chronic periodontitis showed a highly variable virulence, leukotoxin expression, leukotoxicity, internalization and apoptosis of fibroblast, and are regulated both genetically and environmentally.

Aggregatibacter actinomycetemcomitans serotypes and DGGE subtypes in Thai adults with chronic periodontitis.

OBJECTIVE: To investigate the distribution of Aggregatibacter actinomycetemcomitans serotypes and DGGE subtypes among isolates from Thai chronic periodontitis patients. DESIGN: Forty-four adult Thai periodontitis patients were assessed by a full mouth recording for CAL, PPD, and BOP. Seventy-nine strains of A. actinomycetemcomitans were isolated from deep pockets on selective TSBV agar and 17 strains were isolated from shallow pockets. The strains were serotyped using PCR and subtyped using DGGE. RESULTS: The prevalence of A. actinomycetemcomitans was 84.1%. Non-serotypeable A. actinomycetemcomitans strains occurred equally frequent as serotypeable (54.5%); serotype a 18.2%, serotype c 15.9%, serotype e 9.1%, and serotype f 11.4%. Serotype b and d were not detected. A JP2 like strain but serotyped as c was isolated from two patients, and another two strains showed an 886bp insertion on the ltx promoter of their A. actinomycetemcomitans isolates. DGGE typing disclosed 16 different subtypes among the non-serotypeable strains. Two of them (NS1 and NS2) were more common (12.7 and 10.1%) among the strains than the other 14 subtypes (˂5.1%). Most patients showed only one subtype (32.4%) but 29.7% had 2 and 3 different subtypes while 8.1% revealed 4 subtypes in one and the same deep pocket. CONCLUSION: This study showed a greater subtype diversity of A. actinomycetemcomitans predominated by non-serotypeable strains than previously reported in an adult Thai population. It was also revealed for the first time that isolates with a 530bp deletion or 886bp insertion of the ltx promoter were serotyped as serotype c.

Sodium-phosphorylated chitosan/zinc oxide complexes and evaluation of their cytocompatibility: an approach for periodontal dressing.

The aim of this study was to evaluate the possibility of metal complex formation between sodium-phosphorylated chitosan (PCTS) and ZnO. The polymer-metal complex formation was investigated in terms of thermal degradation. The structure deduction of the PCTS/ZnO complex was investigated by means of Fourier transform infrared spectroscopy and X-ray diffraction (XRD). The PCTS/ZnO complexes were formed by the sharing of lone pairs of electrons from the N atoms in the amine groups and O atoms in the phosphate and hydroxyl groups of PCTS to the protonated hydroxyl species on the ZnO surface. Because complex formation occurred at the surface of ZnO particles, it did not change the ZnO crystalline structure. Cytotoxicity, evaluated by a direct contact test with primary human gingival fibroblast cells, revealed that PCTS was biocompatible and reduced the cytotoxicity of ZnO by complexation, making PCTS/ZnO complexes potentially biocompatible. Within the limits of these data, it appears that PCTS could be used as a reaction rate-modifying agent in periodontal dressings.