Helicobacter pylori patient isolates from South Africa and Nigeria differ in virulence factor pathogenicity profile and associated gastric disease outcome

Abstract

Helicobacter pylori is a gram-negative, spiral-shaped bacterial pathogen and the causative agent for gastritis, peptic ulcer disease and classified as a WHO class I carcinogen. While the prevalence of H. pylori infections in Africa is among the highest in the world, the incidence of gastric cancer is comparably low. Little is known about other symptoms related to the H. pylori infection in Africa and the association with certain phenotypes of bacterial virulence. We established a network of study sites in Nigeria (NG) and South Africa (ZA) to gain an overview on the epidemiological situation. In total 220 isolates from 114 patients were analyzed and 118 different patient isolates examined for the presence of the virulence factors cagA, vacA, dupA , their phylogenetic origin and their resistance against the commonly used antibiotics amoxicillin, clarithromycin, metronidazole and tetracycline. We report that H. pylori isolates from Nigeria and South Africa differ significantly in their phylogenetic profiles and in their expression of virulence factors. VacA mosaicism is intensive, resulting in m1-m2 vacA chimeras and frequent s1m1 and s1m2 vacA subtypes in hpAfrica2 strains. Gastric lesions were diagnosed more frequent in Nigerian versus South African patients and H. pylori isolates that are resistant against one or multiple antibiotics occur frequently in both countries.

Curative effect of Omeprazole under different treatment courses in treatment of children with PU and HP infection and its influence on inflammatory factors

“…The occurrence factors of peptic ulcer are complex, including HP infection, excessive gastric acid secretion, infection, systemic diseases, poor diet and living habits, emotional stress, heredity, etc. [17][18][19] When the local inflammatory response of patients is prolonged, the inflammatory response of TNF-a will be enhanced, and even the local inflammatory response will be enhanced. Therefore, the serum levels of IL-6 and TNF-a are closely related to the changes of peptic ulcer.…”

Direct detection of Helicobacter pylori from biopsies of patients in Lagos, Nigeria using real-time PCR—a pilot study

“…Similarly, in one patient, H. pylori was detected in corpus biopsy but absent in the antrum. Palamides et al [ 15 ] reported similar findings in which H. pylori was detected in biopsies from either antrum or corpus of some patients using conventional PCR. This suggest that there are variations in the distribution of H. pylori in the gut of H. pylori infected patients.…”

Helicobacter pylori: an up-to-date overview on the virulence and pathogenesis mechanisms

“…The expression of a specific virulence factor facilitates the interplay between the host and the bacterium [ 39 ]. A recent study by Palamides et al [ 40 ] shows that H. pylori isolates differ in virulence factor and disease outcome. So far, the eradication of H. pylori has become increasingly challenging.…”