The present study aimed to establish a genus-specific PCR-based assay to detect helicobacters using 16S rRNA gene as the target template. We designed the hemi-nested primers based on sequences of 16S rRNA gene of 34 types of Helicobacter species. The inclusivity, sensitivity, and specificity of the PCR assay using these primers were examined in three different models, comprising feces simulated samples, BLAB/c mice infection model and clinic patients samples. The detection sensitivity of Helicobacter pylori, Helicobacter hepaticus and Helicobacter bilis strains from feces simulated samples was all 102 CFU/ml. We successfully detected H. hepaticus and H. bilis in the liver, cecum and feces of experimentally infected mice. H. pylori was successfully detected in the feces samples from 3 patients infected with H. pylori while not in the feces samples from 3 healthy human. However, the C97/C05-C97/C98 PCR assay detected H. pylori in the 2 positive samples. Due to the PCR assay's excellent inclusivity, high sensitivity and specificity it may be used to detect the presence of Helicobacters.
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.