Comparison of invasive histological and molecular methods in the diagnosis of Helicobacter pylori from gastric biopsies of Sudanese patients: a cross-sectional study

A Review of Helicobacter pylori Diagnostics in Africa : From the Bedside to the Laboratory

Helicobacter pylori (H. pylori) is endemic in Africa with a prevalence estimate of 79.1%. In addition, there is a significant community burden of dyspepsia in Africa, similar to other western countries. However, the majority of infected persons do not manifest the disease. In Africa, for instance, peptic ulcer disease is prevalent, whereas gastric cancer has reportedly low incidence. Therefore, it is important that testing is focused, targeting individuals most likely to benefit from treatment. In Africa, there are currently no guidelines for H. pylori testing and treatment. Empirical treatment is common due to variable access to diagnostics and health care. To assess the spectrum of H. pylori testing in Africa, we performed a literature search in PubMed over the past 10 years, 2013 to 2023. Histology was the most widely used modality in 16 out of 18 countries. Capacity for culture was shown in 11 studies, importantly across regions of Africa. H. pylori serology was demonstrated in 8 countries, although it has limited sensitivity in identifying active infection. H. pylori test-and-treat strategy has been shown to be cost-effective. Particularly in a region with high antibiotic resistance, adopting this strategy ensures that only confirmed positive patients are treated. Furthermore, test-of-cure ought to be mandatory to guide future therapies. Health authorities can leverage polymerase chain reaction facilities, left behind by the coronavirus disease 2019 pandemic, to make molecular susceptibility testing available in the near future. A systematic approach to testing incorporating indication for endoscopy and medication use is recommended.

Usefulness of Molecular Methods for Helicobacter pylori Detection in Pediatric Patients and Their Correlation with Histopathological Sydney Classification

Helicobacter pylori infections, as one of the most prevalent among humans, are generally acquired during childhood, and are one of the main causes of chronic gastritis and peptic ulcer disease. A bacterial culture from a gastric biopsy is the gold standard and is the only method that has 100% specificity. However, its sensitivity varies, depending on experience of the laboratory staff, applied culture media, specimen transport conditions, biopsy site, and quality of the sample. The same factors compromise all invasive methods and a culture-based H. pylori infection diagnostic, as well as a recent intake of antibiotics, bismuth-containing compounds, and proton pump inhibitors. Molecular methods have been used for clinical microbiology investigation since the beginning of the 21st century. However, their usefulness for H. pylori infections diagnosis remains unclear, especially in pediatric patients. The aim of the study was to assess the incidence of H. pylori infections in a group of 104 pediatric patients and to compare the results of the PCR test with the corresponding histopathological investigation effects. Among the biopsy samples collected from 104 children, 44 (42.3%) were positive in PCR, while 43 (41.3%) and 39 (37.5%) presented histologically-confirmed signs of inflammation and H. pylori colonization, respectively. Moreover, the mean grades of the parameters of the histopathological examination were higher in the group of PCR-positive samples. The compatibility of both research methods was confirmed, emphasizing the usefulness of molecular methods for detecting H. pylori infections in pediatric patients. Considering that the PCR-based method gives reliable results and is less time-consuming and costly, it is worth discussing this method as a new standard in the diagnosis of H. pylori infections, at least among pediatric patients, for which culture-based diagnostics is not sufficient or histopathological examination is negative, while inflammation signs are observed macroscopically.

Molecular detection of Helicobacter spp. and Fusobacterium gastrosuis in pigs and wild boars and its association with gastric histopathological alterations

Besides Helicobacter pylori, a Gram-negative bacterium that may cause gastric disorders in humans, non-Helicobacter pylori helicobacters (NHPH) may also colonize the stomach of humans and animals. In pigs, H. suis can induce gastritis and may play a role in gastric ulcer disease, possibly in association with Fusobacterium gastrosuis. In the present study, gastric samples from 71 slaughtered pigs and 14 hunted free range wild boars were tested for the presence of DNA of F. gastrosuis and gastric Helicobacter species associated with pigs, dogs cats and humans, using species-specific PCR assays, followed by sequencing of the amplicon. These gastric samples were also histopathologically evaluated. Almost all the pigs presented gastritis (95.8%). Helicobacter spp. were detected in 78.9% and F. gastrosuis in 35.2% of the animals. H. suis was the most frequently identified Helicobacter species (57.7% of the animals), followed by a H. pylori-like species (50.7%) and less often H. salomonis and H. felis (each in 2.8% of the animals). H. suis was most often detected in the glandular (distal) part of the stomach (pars oesophagea 9.9%, oxyntic mucosa 35.2%, antral mucosa 40.8%), while the H. pylori-like species was mainly found in the non-glandular (proximal) part of the stomach (pars oesophagea 39.4%, oxyntic mucosa 14.1%, antral mucosa 4.2%). The great majority of wild boars were also affected with gastritis (71.4%) and Helicobacter spp. and F. gastrosuis were detected in 64.3% and 42.9% of the animals, respectively. H. bizzozeronii and H. salomonis were the most frequently detected Helicobacter species, while a H. pylori-like species and H. suis were only occasionally identified. These findings suggest that these microorganisms can colonize the stomach of both porcine species and may be associated with gastric pathology. This should, however, be confirmed through bacterial isolation. This is the first description of the presence of F. gastrosuis DNA in the stomach of wild boars and a H. pylori-like species in the pars oesophagea of the porcine stomach.