Séroprévalence de l’infection à Helicobacter Pylori dans une population mauritanienne asymptomatique

Histomolecular profile of Helicobacter pylori strains circulating in Brazzaville (Congo)

Background and Aim

Helicobacter pylori (Hp) infection is a real public health problem in the Congo. We aimed study the histomolecular profile of Hp strains circulating in Brazzaville, Congo, in order to contribute to the improvement of Hp-infected patients in the country.

Methods

This was an analytical-transversal study carried out from January to November 2020 (i.e. a study period of 11 months) in the endoscopy centers of Brazzaville as well as the molecular biology and anatomopathology laboratories of Pointe-Noire and Oyo. It involved 100 symptomatic patients over the age of 18 referred for upper GI endoscopy. These patients underwent gastric biopsies for histopathological analysis according to the Sydney classification and molecular analysis using the real-time polymerase chain reaction (PCR) technique. The frequency of Hp infection was determined using real-time PCR. PCR was also used to identify the Hp strains and assess their tropism in the gastric mucosa. Digestive symptoms, endoscopic lesions, and histopathological lesions associated with HP infection were studied.

Results

The incidence of Hp infection was 91%, with a female predominance of 52.75% and an average age of 46.32 years. Endoscopy revealed normal mucosa (56.14%), ulcerated lesions (12.28%), and gastritis (22.81%) in infected patients. Histopathologically, the lesions were chronic atrophic gastritis (91%), with inflammatory activity (16.46%), intestinal metaplasia (16.46%), and adenocarcinoma (3.3%). Cag A strains were present in 85.71% of cases and had no preferential tropism in the gastric mucosa. Strains carrying the Cag A gene were present in severe and serious endoscopic and histopathological lesions.

Conclusion

The prevalence of Hp infection is 91% in the Brazzaville population. Cag A strains circulate in high proportions and are implicated in the occurrence of severe lesions of the gastric mucosa.

Characteristics of Helicobacter pylori strains isolated from Mauritanian patients

BACKGROUND

Helicobacter pylori (H pylori) is responsible for various diseases including cancer It co-evolved with humans, and human migrations shaped the expansion and the diversity of strains around the world. The risk of developing a disease depends on virulence factors, mainly the cytotoxin-associated gene A protein (CagA). The aim of this study was to determine the cagA status in H pylori strains from Mauritanian patients and to search for a relationship with endoscopic and histologic findings.

MATERIAL AND METHODS

H pylori was searched in gastric biopsies taken during endoscopy in patients with gastro-duodenal symptoms. RT-PCR was used for the diagnosis and resistance to clarithromycin. The cagA status was determined with PCR and the EPIYA-cagA polymorphism with sequencing.

RESULTS

At all, 76/78 (97.4%) biopsies were positive. The rate of clarithromycin resistance was 4/76 (5.26%) due to the A2143G mutation, with a mixed population in 2 cases. The cagA gene was present in 23/76 (30.26%) biopsies, and the EPIYA motif was ABC in 21 (91.3%). High bacterial load and inflammation were significantly associated with cagA-positive status (P < .01). Phylogenetic analysis of the glmM and hspA genes highlighted a mixture of African and European genes in strains of H pylori isolated from patients of Moor origin.

CONCLUSION

We report a high prevalence of H pylori infection in Mauritanian patients, a low rate of clarithromycin resistance (5.26%) and high bacterial load and inflammation associated with cagA-positive status. The phylogenetic analysis highlights the mix of different populations leading to the Moor ethnicity.