Peptic ulcer disease

Clarithromycin resistance and efficacy of clarithromycin-containing triple eradication therapy for Helicobacter pylori infection in type 2 diabetes mellitus patients

BACKGROUND

Antimicrobial resistance in Helicobacter pylori infection is an important factor leading to failure of therapy. The aim of this study was to determine the eradication rate of H pylori in type 2 diabetes mellitus and to assess the effect of clarithromycin resistance on H pylori eradication.

METHOD

Fifty-six consecutive patients with type 2 diabetes mellitus and 58 age- and sex-matched control patients were included in the study. H pylori infection was assessed by a rapid urease test and histopathological examination of biopsy specimens. Biopsies were also taken for antibiotic susceptibility testing. All enrolled patients were treated with triple therapy consisting of clarithromycin, amoxicillin, and pantoprazole for 14 days. C-13 urea breath test was performed 6 weeks after completing the triple therapy to assess eradication and associated point mutations using real-time polymerase chain reaction (PCR).

RESULTS

H pylori was eradicated in 42.9% of diabetic patients and 79.3% of control patients, (P < 0.05). In type 2 diabetes mellitus patients, clarithromycin resistance was 64.3% (36/56), while in the control group, clarithromycin resistance was 35.7% (20/58) (P < 0.05). H pylori was eradicated in 14 (70%) of the 20 clarithromycin-susceptible diabetic patients and in only 10 (27.8%) of the 36 clarithromycin-resistant diabetic patients.

CONCLUSION

The H pylori eradication rate was significantly lower and clarithromycin resistance was significantly higher in type 2 diabetics. Alternative and new treatment protocols and antibiotic susceptibility testing are needed to achieve successful eradication rates.

Upregulation of a non-heme iron-containing ferritin with dual ferroxidase and DNA-binding activities in Helicobacter pylori under acid stress

Helicobacter pylori is a spiral Gram-negative microaerophilic bacterium. It is unique and distinctive among various bacterial pathogens for its ability to persist in the extreme acidic environment of human stomachs. To address and identify changes in the proteome of H. pylori in response to low pH, we have used a proteomic approach to study the protein expression of H. pylori under neutral (pH 7) and acidic (pH 5) conditions. Global protein-expression profiles of H. pylori under acid stress were analysed by two-dimensional polyacrylamide gel electrophoresis (2-DE) followed by liquid chromatography (LC)-nanoESI-mass spectrometry (MS)/MS and bioinformatics database analysis. Among the proteins differentially expressed under acidic condition, a non-heme iron-containing ferritin of H. pylori (HP-ferritin) was found to be consistently upregulated at pH 5 as compared to pH 7. It was also found that HP-ferritin can switch from an iron-storage protein with ferroxidase activity to a DNA-binding/protection function under in vitro conditions upon exposure to acidic environment. Prokaryotic ferritins, such as non-heme iron-binding HP-ferritin with dual functionality reported herein, may play a significant urease-independent role in the acid adaptation of H. pylori under physiological conditions in vivo.

The role of psychosocial factors in peptic ulcer disease: beyond Helicobacter pylori and NSAIDs

A variety of organic etiologies are associated with peptic ulcer disease, and the most relevant of these are infection with Helicobacter pylori and use of nonsteroidal anti-inflammatory drugs. Between 5% and 20% of patients with gastric or duodenal ulcer, however, lack an identifiable organic etiology. In these patients particularly and in all ulcer patients in general, psychosocial factors may play a significant role. At present, there is no definitive study proving a causal relationship between psychological stress and the development of ulcer disease. Studies to date suffer from significant methodological limitations and have not effectively addressed the poor correlation between ulcer craters and ulcer symptoms. A conservative application of available data would suggest that psychosocial factors play a significant role in symptom perception and reporting in patients with dyspeptic symptoms and may play a role in ulcer formation.