Non-urease producing Helicobacter pylori in chronic gastritis

Altered cytokine expression in Helicobacter pylori infected patients with bleeding duodenal ulcer

Objective

Peptic ulcer disease is a condition in which an important role has infection with H. pylori. The most common complication of peptic ulcer is bleeding. The presence of H. pylori triggers local and systemic cytokine signaling which may affect processes such as healing, gastric or duodenal rupture, and carcinogenesis. In this study, we examined the concentrations of IL-1β, IL-6, IL-10, TNF, TGF-β and IL-17A in serum by enzyme immunoassay and their mRNA expressions in periulcer biopsies obtained from patients with bleeding peptic ulcer by means of real-time-PCR.

Results

We have shown that pro-inflammatory IL-6 and TNF concentrations in serum were significantly higher in patients who were infected with H. pylori, while the concentrations of TGF-β and IL-17A were significantly lower compared to non-infected subjects. IL-17A expression in periulcer mucosa was significantly higher in patients who were infected with H. pylori, while the expression of other cytokines, there was no significant difference compared to non-infected controls. Considering higher serum concentrations in non-infected subjects and higher IL-17A expression in mucosal tissue of infected patients, our data support the studies that found IL-17A has protective role in eradication of H. pylori infection in infected patients.

Electronic supplementary material

The online version of this article (10.1186/s13104-019-4310-4) contains supplementary material, which is available to authorized users.

Molecular evidence of Helicobacter cinaedi organisms in human gastric biopsy specimens

One hundred twenty-six urease-negative gastric biopsy specimens were evaluated for the presence of Helicobacter genus-specific 16S ribosomal DNA (rDNA) and H. pylori-specific glmM DNA sequences by PCR. The species specificity of the glmM PCR assay was demonstrated, as H. pylori was the only Helicobacter species that yielded the expected glmM amplicon. Most urease-negative specimens (118 of 126 specimens) lacked Helicobacter DNA. However, 8 of 126 urease-negative specimens contained Helicobacter 16S rDNA. In order to identify the Helicobacter species present in urease-negative gastric biopsy specimens, 16S rDNA amplicons were cloned and sequenced. Sequence comparisons were performed by analyses of the sequences in public sequence databases. Two samples contained 16S rDNA that was identified as H. cinaedi with 100% identity and that spanned approximately 400 bp (398 and 398 bp, respectively). In contrast, multiple differences (97% identity; 390 of 398 bp) were observed with H. pylori 16S rDNA in this region. This finding was verified by sequencing an overlapping 537-bp fragment within the 5' portion of 16S rDNA. Although the clinical findings were consistent with H. pylori infection (e.g., duodenal ulcer disease), rapid urease testing and DNA sequence analyses suggested the presence of H. cinaedi organisms and the absence of H. pylori in two human antral biopsy specimens. This study represents the first report of an enteric urease-negative helicobacter in the human stomach. Although these organisms were previously associated with extragastric infections, the roles of these organisms in the pathogenesis of chronic gastritis or peptic ulcer disease remain unclear.

Is there another chapter in the Helicobacter pylori/peptic ulcer disease story?

The role of Helicobacter pylori in the production of mucosal damage has largely been considered within a simple infection paradigm, because to date eradication has appeared to be a predictable outcome of antibiotic therapy. Changes in the epidemiology and management of peptic ulcer disease, however, require a more comprehensive framework to understand these shifting clinical patterns. The present review examines mucosal damage as an outcome of a complicated host-parasite relationship, with alterations in both parasite physiology and host defence mechanisms being keys to understanding disease patterns.