Irish gerontological society

Evaluation of a novel heminested PCR assay based on the phosphoglucosamine mutase gene for detection of Helicobacter pylori in saliva and dental plaque

A novel heminested PCR protocol was developed for the specific detection of Helicobacter pylori at low copy numbers. A set of primers specific for the phosphoglucosamine mutase gene (glmM) of H. pylori produced a 765-bp fragment that was used as template for the heminested primer pair delineating a 496-bp fragment. By using agarose gel electrophoresis for detection of the heminested PCR-amplified products, amplification of H. pylori genomic DNA was achieved at concentrations as low as 0.1 pg, equivalent to 5 x 10(2) bacteria. A study was subsequently undertaken to evaluate the heminested PCR for detection of H. pylori in dental plaque and saliva. Specimens collected from 58 individuals were cultured, and PCR was subsequently performed on the oral cultures. Identification of H. pylori in the same series of saliva and dental plaque specimens was carried out with PCR using a primer pair specific for the H. pylori urease B gene and by the heminested PCR assay. The identity of the amplified products was confirmed by DNA sequencing. Our results demonstrate that the heminested PCR assay was specific for detection of H. pylori, yielding no false-positive results, and that H. pylori had a low prevalence (approximately 3%) in specimens obtained from the oral cavity.

Oral carriage of Helicobacter pylori: a review

Helicobacter pylori is a microaerophilic, motile bacterium, especially adapted to life in the human stomach. The presence of H. pylori in the stomach is strongly associated with chronic gastritis and ulcer disease and is a risk factor for gastric cancers. The microorganism may be transmitted orally and has been detected in dental plaque, saliva, and feces, but the hypothesis that oral microflora may be a permanent reservoir of H. pylori is still controversial. A review of the literature suggests that the recovery of H. pylori in the mouth is probably intermittent, associated with gastroesophageal reflux but not with specific oral disease. Nonetheless, the PCR identification of oral H. pylori may become helpful, particularly in cases of gastritis or ulcer relapse after antimicrobial therapy. Eradication of oral H. pylori by local medication or periodontal procedures would rely on the precise identification of its ecological niche. Within family groups, prophylactic methods should be practiced to avoid oral carriage of H. pylori. The risk of iatrogenic transmission during dental care, however, is already circumscribed by standard professional hygiene procedures.

Role of dental plaque in the transmission of Helicobacter pylori infection

With regard to the role of dental plaque in the transmission of Helicobacter pylori infection, data from the literature vary greatly, owing to differences in sample collection and H. pylori-detecting techniques. Using the polymerase chain reaction (PCR), we have determined the incidence of H. pylori colonization in the dental plaque of 31 consecutive patients who underwent gastroscopy. The patients were divided into two groups on the basis of H. pylori infection, determined by Giemsa stain and the rapid urease test: group A made up of 21 H. pylori-positive patients and group B with 10 H. pylori-negative patients. Our PCR assay of dental plaque samples proved negative in all group A subjects but was positive in only one patient in group B. In our study, we found that H. pylori had a low prevalence (3.2%) in the oral cavity, with no significant relationship between gastric mucosa and dental plaque colonization. More comprehensive studies are needed to determine whether dental plaque is an important reservoir in the epidemiology of H. pylori-induced gastric disease.

Prevention of duodenal ulcer relapse with omeprazole 20 mg daily: a randomized double-blind, placebo-controlled study

We report the first double-blind, placebo-controlled study that assesses the efficacy and safety of omeprazole 20 mg daily in the maintenance treatment of duodenal ulcer. For the healing phase, 128 patients with endoscopically proven active duodenal ulcer and a history of three or more relapses during the 2 years prior to the study were treated until healing with omeprazole 40 mg daily for 2 and up to 8 weeks. One hundred and twenty-three patients whose ulcers were healed were randomized to receive omeprazole 20 mg daily (n = 60) or placebo (n = 63) for 12 months as maintenance treatment. Patients were interviewed at 3, 6, 9 and 12 months, and endoscopy was performed at 3, 6 and 12 months and whenever symptoms recurred. The healing rates of the 124 patients completing the healing phase were 84, 98 and 100% at 2, 4 and 8 weeks, respectively. During the maintenance phase, eight and four patients discontinued treatment from the omeprazole and placebo groups, respectively. The proportion of patients in remission in the omeprazole group and placebo group after 12 months were 94 and 9% respectively (life table estimates, P < 0.0001). No significant clinical or laboratory changes were observed in patients on therapy with omeprazole. Patients with a history of frequent relapses thus continued to have a very high relapse rate without prophylactic treatment. Omeprazole 20 mg daily was effective and safe in maintaining such patients in remission.

Helicobacter pylori prevalence in endoscopy and medical staff

The epidemiology and mode of transmission of Helicobacter pylori is currently unclear; it is postulated that the human stomach is the natural reservoir and that spread occurs by faecal-oral or oral-oral transmission. The aim of this study was to assess the prevalence of H. pylori in gastroenterologists and gastroenterology nurses compared with internists, general nurses and the normal population. An enzyme-linked immunosorbent assay technique (sensitivity 96%, specificity 88%) was used to detect circulating H. pylori immunoglobulin G antibodies in 39 gastroenterologists, 107 gastroenterology nurses, 25 internists and 42 general nurses. These subjects were compared to an age- and sex-matched Caucasian population obtained by random sampling of an urban population area. The overall prevalence of H. pylori in gastroenterologists was 69% compared to 40% of internists (P < 0.01), 17% of gastroenterology nurses (P < 0.001), 19% of general nurses (P < 0.01) and 32% of controls (P < 0.01). There was no significant difference in H. pylori prevalence between the gastroenterology nurses and controls, general nurses and controls. The prevalence in gastroenterologists increased with years of practice to levels greater than age-matched controls. The prevalence in gastroenterology nurses increased with age and years of working and was similar to age-matched control subjects. These findings of an increased prevalence of H. pylori infection in gastroenterologists performing endoscopy support human-to-human transmission possibly from patients to medical staff.