Surviving stomach bugs in UK ethnic groups: a qualitative study.

BACKGROUND: The exposure patterns across ethnic groups are unclear for stomach bugs that cause self-limiting symptoms, significantly burdening UK health-care services and the economy. This study seeks to fill this gap by exploring how inequalities arise in managing stomach bugs in UK ethnic groups. METHODS: A qualitative study using semi-structured interviews was undertaken. Ethics approval was given by the University of Liverpool, and data were collected by IZ over 11 months from July 26, 2022, and May 26, 2023. Purposive sampling was used to recruit a general UK population sample (excluding health-care professionals) who were adults, partners, and parents, from an ethnic minority group, with recent diarrhoea, vomiting, or a stomach bug over the past 6 months. Recruitment was conducted through community gatekeepers using flyers. Participants were interviewed in person or virtually and gave written informed consent. An incentive of an Amazon voucher of £10 was imbursed to participants for their time. Interviews were audio-recorded using a password-protected digital recorder, transcribed verbatim, and analysed using reflexive thematic analysis. FINDINGS: 36 interviews (median age 31·5 years) were conducted with 11 women of Pakistani (n=6), Bangladeshi (n=2), Indian (n=2) and Arab ethnicity (n=1), and 25 men of Black (n=22), Pakistani (n=2), and Indian (n=1) ethnicity. This sample enabled an exploration of within-ethnic group experiences of stomach bugs in participants who self-defined their age, sex, and ethnicity. Themes such as managing food preparation (n=16), travel abroad (n=17), and personal cleanliness (n=3) were consistently reported across transcripts. The findings corroborate existing literature that there are more similarities than divergences in the management of stomach bugs across ethnic groups, such as the burden of care disproportionately affecting women and using over-the-counter medication to manage symptoms. INTERPRETATION: We do not know if the impact of these experiences across ethnic groups is entirely representative of the broader ethnic categories (ie, Asian vs Indian, Pakistani, and Bangladeshi) they belong to or if there are inequalities in their impact on ethnic groups living in different circumstances (ie, UK born vs migrant). FUNDING: National Institute for Health and Care Research (NIHR).

Helicobacter pylori and Epstein-Barr Virus Co-Infection in Gastric Disease: What Is the Correlation with p53 Mutation, Genes Methylation and Microsatellite Instability in a Cohort of Sicilian Population?

Genetic predisposition, environmental factors, and infectious agents interact in the development of gastric diseases. Helicobacter pylori (Hp) and Epstein-Barr virus (EBV) infection has recently been shown to be correlated with these diseases. A cross-sectional study was performed on 100 hospitalized Italian patients with and without gastric diseases. The patients were stratified into four groups. Significant methylation status differences among CDH1, DAPK, COX2, hMLH1 and CDKN2A were observed for coinfected (Hp-EBV group) patients; particularly, a significant presence of COX2 (p = 0.0179) was observed. For microsatellite instability, minor stability was described in the Hp-HBV group (69.23%, p = 0.0456). Finally, for p53 mutation in the EBV group, exon 6 was, significantly, most frequent in comparison to others (p = 0.0124), and in the Hp-EBV group exon 8 was, significantly, most frequent in comparison to others (p < 0.0001). A significant positive relationship was found between patients with infection (Hp, EBV or both) and p53 mutation (rho = 0.383, p = 0.0001), methylation status (rho = 0.432, p < 0.0001) and microsatellite instability (rho = 0.285, p = 0.004). Finally, we observed among infection and methylation status, microsatellite instability, and p53 mutation a significant positive relationship only between infection and methylation status (OR = 3.78, p = 0.0075) and infection and p53 mutation (OR = 6.21, p = 0.0082). According to our analysis, gastric disease in the Sicilian population has different pathways depending on the presence of various factors, including infectious agents such as Hp and EBV and genetic factors of the subject.

Mitochondrial DNA Haplogroup Related to the Prevalence of Helicobacter pylori.

Mitochondria are essential organelles that are not only responsible for energy production but are also involved in cell metabolism, calcium homeostasis, and apoptosis. Targeting mitochondria is a key strategy for bacteria to subvert host cells' physiology and promote infection. Helicobacter (H.) pylori targets mitochondria directly. However, mitochondrial genome (mtDNA) polymorphism (haplogroup) is not yet considered an important factor for H. pylori infection. Here, we clarified the association of mitochondrial haplogroups with H. pylori prevalence and the ability to perform damage. Seven mtDNA haplogroups were identified among 28 H. pylori-positive subjects. Haplogroup B was present at a higher frequency and haplotype D at a lower one in the H. pylori population than in that of the H. pylori-negative one. The fibroblasts carrying high-frequency haplogroup displayed a higher apoptotic rate and diminished mitochondrial respiration following H. pylori infection. mtDNA mutations were accumulated more in the H. pylori-positive population than in that of the H. pylori-negative one in old age. Among the mutations, 57% were located in RNA genes or nonsynonymous protein-coding regions in the H. pylori-positive population, while 35% were in the H. pylori-negative one. We concluded that gastric disease caused by Helicobacter virulence could be associated with haplogroups and mtDNA mutations.

Investigating Helicobacter pylori-related pyloric hypomotility: functional, histological, and molecular alterations.

Multiple theories have been proposed describing the pathogenic mechanisms of Helicobacter pylori (H. pylori)-associated gastric motility disorders. We assessed ex vivo pyloric activity in H. pylori-infected rats, and tried to explore the associated ghrelin hormone alteration and pyloric fibrogenesis. In addition, miR-1 was assessed in pyloric tissue samples, being recently accused of having a role in smooth muscle dysfunction. Ninety adult male Wistar albino rats were assigned into nine groups: 1) control group, 2) sterile broth (vehicle group), 3) amoxicillin control, 4) omeperazole control, 5) clarithromycin control, 6) triple therapy control, 7) H. pylori- group, 8) H. pylori-clarithromycin group, and 9) H. pylori-triple therapy group. Urease enzyme activity was applied as an indicator of H. pylori infection. Ex vivo pyloric contractility was evaluated. Serum ghrelin was assessed, and histological tissue evaluation was performed. Besides, pyloric muscle miR-1 expression was measured. The immunological epithelial to mesenchymal transition (EMT) markers; transforming growth factor ß (TGFß), α-smooth muscle actin (α-SMA), and E-cadherin-3 were also evaluated. By H. pylori infection, a significant (P < 0.001) reduced pyloric contractility index was recorded. The miR-1 expression was decreased (P < 0.001) in the H. pylori-infected group, associated with reduced serum ghrelin, elevated TGFß, and α-SMA levels and reduced E-cadherin levels. Decreased miR-1 and disturbed molecular pattern were improved by treatment. In conclusion, H. pylori infection was associated with reduced miR-1, epithelial to mesenchymal transition, and pyloric hypomotility. The miR-1 may be a target for further studies to assess its possible involvement in H. pylori-associated pyloric dysfunction, which might help in the management of human H. pylori manifestations and complications.NEW & NOTEWORTHY This work is investigating functional, histopathological, and molecular changes underlying Helicobacter pylori hypomotility and is correlating these with miR-1, whose disturbance is supposed to be involved in smooth muscle dysfunction and cell proliferation according to literature. Epithelial to mesenchymal transition and reduced ghrelin hormone may contribute to H. pylori infection-associated hypomotility. H. pylori infection was associated with reduced pyloric miR-1 expression. Targeting miR-1 could be valuable in the clinical management of pyloric hypofunction.

Analysis of long-term results of pathogenetic treatment of Helicobacter pylori-associated gastroduodenopathies induced by nonsteroidal anti-inflammatory drugs in patients with osteoarthritis.

The study of the pathogenetic treatment and prevention of Helicobacter pylori (Hp)-associated gastroduodenopathies (GDP) induced by nonsteroidal anti-inflammatory drugs (NSAIDs) in patients with osteoarthritis (OA) is one of the most serious problems in modern clinical medicine. Sixty patients with OA and concomitant Hp-associated GDP induced by NSAIDs were examined. The levels of epidermal growth factor (EDF), sAPO-1/Fas and tumor necrosis factor-α (TNF-α) were determined. Group I included 30 patients who received triple anti-Helicobacter (AHT) therapy, and group II included 30 patients who received rebamipide. Long-term effects were assessed 6 months and 1 year after treatment. All subjects showed a significant increase in TNF-α (4.7 times), EDF (2.2 times) and a decrease in sAPO-1/Fas (3.6 times) levels compared to healthy individuals. After 1 month of treatment, a significantly more significant decrease in TNF-α and an increase in sAPO-1/Fas and EDF was found in group II. In the long-term treatment, a further decrease in TNF-α and an increase in the content of sAPO-1/Fas levels were observed in all groups. However, these changes were significantly more significant in group I compared to group I. The long-term follow-up showed a declining trend of EDF in all groups. The data obtained indicate the effectiveness of rebamipide in the complex pathogenetic treatment and prevention of Hp-associated GDP induced by NSAIDs in patients with OA.

Mucosal microbial microenvironment in early gastric neoplasia and non-neoplastic gastric disease.

BACKGROUND AND AIM: The biological characterization of microbial environment in early gastric cancer (EGC), other than Helicobacter pylori, is limited. This study aimed to explore the microbial microenvironment in chronic gastritis (CG), fundic gland polyps (FGPs), low-grade intraepithelial neoplasia (LGIN), and EGC. METHODS: 16S-rRNA gene sequencing and bioinformatic analysis were performed on 63 individuals with 252 mucosal biopsies or endoscopic submucosal dissection margin samples from endoscopy. RESULTS: The microbiota in gastric LGIN functions analogously to EGC in terms of functional prediction. Neoplastic lesions showed a significant difference to CG or FGPs in beta diversity of the microbiota. Bacteria genera including Paracoccus, Blautia, Barnesiella, Lactobacillus, Thauera, Collinsella were significantly enriched in gastric neoplastic mucosa (LGIN and EGC) compared with non-neoplastic tissues (CG and FGPs). While Pseudomonas and Kingella were depleted in neoplastic tissues. FGPs showed a distinctive microbial network system that negatively interacted with Helicobacter. CONCLUSIONS: In terms of the mucosal microbial microenvironment, gastric LGIN and EGC showed no significant difference as early neoplastic lesions. We observed a coordinated microbial microenvironment that correlated negatively with Helicobacter.

Helicobacter pylori Outer Membrane Vesicles and Extracellular Vesicles from Helicobacter pylori-Infected Cells in Gastric Disease Development.

Extracellular vesicles (EVs) are cell-derived vesicles important in intercellular communication that play an essential role in host-pathogen interactions, spreading pathogen-derived as well as host-derived molecules during infection. Pathogens can induce changes in the composition of EVs derived from the infected cells and use them to manipulate their microenvironment and, for instance, modulate innate and adaptive inflammatory immune responses, both in a stimulatory or suppressive manner. Gastric cancer is one of the leading causes of cancer-related deaths worldwide and infection with Helicobacter pylori (H. pylori) is considered the main risk factor for developing this disease, which is characterized by a strong inflammatory component. EVs released by host cells infected with H. pylori contribute significantly to inflammation, and in doing so promote the development of disease. Additionally, H. pylori liberates vesicles, called outer membrane vesicles (H. pylori-OMVs), which contribute to atrophia and cell transformation in the gastric epithelium. In this review, the participation of both EVs from cells infected with H. pylori and H. pylori-OMVs associated with the development of gastric cancer will be discussed. By deciphering which functions of these external vesicles during H. pylori infection benefit the host or the pathogen, novel treatment strategies may become available to prevent disease.

Isolation and characterization of Helicobacter suis from human stomach.

Helicobacter suis, a bacterial species naturally hosted by pigs, can colonize the human stomach in the context of gastric diseases such as gastric mucosa-associated lymphoid tissue (MALT) lymphoma. Because H. suis has been successfully isolated from pigs, but not from humans, evidence linking human H. suis infection to gastric diseases has remained incomplete. In this study, we successfully in vitro cultured H. suis directly from human stomachs. Unlike Helicobacter pylori, the viability of H. suis decreases significantly on neutral pH; therefore, we achieved this using a low-pH medium for transport of gastric biopsies. Ultimately, we isolated H. suis from three patients with gastric diseases, including gastric MALT lymphoma. Successful eradication of H. suis yielded significant improvements in endoscopic and histopathological findings. Oral infection of mice with H. suis clinical isolates elicited gastric and systemic inflammatory responses; in addition, progression of gastric mucosal metaplasia was observed 4 mo postinfection. Because H. suis could be isolated from the stomachs of infected mice, our findings satisfied Koch's postulates. Although further prospective clinical studies are needed, H. suis, like H. pylori, is likely a gastric pathogen in humans. Furthermore, comparative genomic analysis of H. suis using complete genomes of clinical isolates revealed that the genome of each H. suis isolate contained highly plastic genomic regions encoding putative strain-specific virulence factors, including type IV secretion system-associated genes, and that H. suis isolates from humans and pigs were genetically very similar, suggesting possible pig-to-human transmission.

Increased Risk of Severe Gastric Symptoms by Virulence Factors vacAs1c, alpA, babA2, and hopZ in Helicobacter pylori Infection.

Two virulence factors of Helicobacter pylori, cagA and vacA, have been known to play a role in the development of severe gastric symptoms. However, they are not always associated with peptic ulcer or gastric cancer. To predict the disease outcome more accurately, it is necessary to understand the risk of severe symptoms linked to other virulence factors. Several other virulence factors of H. pylori have also been reported to be associated with disease outcomes, although there are many controversial descriptions. H. pylori isolates from Koreans may be useful in evaluating the relevance of other virulence factors to clinical symptoms of gastric diseases because the majority of Koreans are infected by toxigenic strains of H. pylori bearing cagA and vacA. In this study, a total of 116 H. pylori strains from Korean patients with chronic gastritis, peptic ulcers, and gastric cancers were genotyped. The presence of virulence factors vacAs1c, alpA, babA2, hopZ, and the extremely strong vacuolating toxin was found to contribute significantly to the development of severe gastric symptoms. The genotype combination vacAs1c/alpA/babA2 was the most predictable determinant for the development of severe symptoms, and the presence of babA2 was found to be the most critical factor. This study provides important information on the virulence factors that contribute to the development of severe gastric symptoms and will assist in predicting clinical disease outcomes due to H. pylori infection.

Helicobacter pylori, clinical, laboratory, and noninvasive biomarkers suggestive of gastric damage in healthy school-aged children: A case-control study.

BACKGROUND: Helicobacter pylori is acquired largely in early childhood, but its association with symptoms and indirect biomarkers of gastric damage in apparently healthy children remains controversial. We aimed to relate persistent H. pylori infection in apparently healthy school-aged children with clinical, laboratory, and noninvasive biomarkers suggestive of gastric damage using a case-control design. MATERIALS AND METHODS: We followed up 83 children aged 4-5 years with persistent H. pylori infection determined by stool antigen detection and/or a urea breath test and 80 noninfected matched controls from a low-income to middle-income, periurban city in Chile for at least 3 years. Monitoring included clinical visits every 4 months and annual assessment by a pediatric gastroenterologist. A blood sample was obtained to determine laboratory parameters potentially associated with gastric damage (hemogram and serum iron and ferritin levels), biomarkers of inflammation (cytokines, pepsinogens I and II, and tissue inhibitor metalloproteinase 1), and expression of cancer-related genes KLK1, BTG3, and SLC5A8. RESULTS: Persistently infected children had higher frequency of epigastric pain on physical examination (40% versus 16%; P = 0.001), especially from 8 to 10 years of age. No differences in anthropometric measurements or iron-deficiency parameters were found. Persistent infection was associated with higher levels of pepsinogen II (median 12.7 ng/mL versus 9.0 ng/mL; P < 0.001); no difference was observed in other biomarkers or gene expression profiles. CONCLUSIONS: H. pylori infection in apparently asymptomatic school-aged children is associated with an increase in clinical symptoms and in the level of one significant biomarker, pepsinogen II, suggesting early gastric involvement.

Helicobacter pylori diversification during chronic infection within a single host generates sub-populations with distinct phenotypes.

Helicobacter pylori chronically infects the stomach of approximately half of the world's population. Manifestation of clinical diseases associated with H. pylori infection, including cancer, is driven by strain properties and host responses; and as chronic infection persists, both are subject to change. Previous studies have documented frequent and extensive within-host bacterial genetic variation. To define how within-host diversity contributes to phenotypes related to H. pylori pathogenesis, this project leverages a collection of 39 clinical isolates acquired prospectively from a single subject at two time points and from multiple gastric sites. During the six years separating collection of these isolates, this individual, initially harboring a duodenal ulcer, progressed to gastric atrophy and concomitant loss of acid secretion. Whole genome sequence analysis identified 1,767 unique single nucleotide polymorphisms (SNPs) across isolates and a nucleotide substitution rate of 1.3x10-4 substitutions/site/year. Gene ontology analysis identified cell envelope genes among the genes with excess accumulation of nonsynonymous SNPs (nSNPs). A maximum likelihood tree based on genetic similarity clusters isolates from each time point separately. Within time points, there is segregation of subgroups with phenotypic differences in bacterial morphology, ability to induce inflammatory cytokines, and mouse colonization. Higher inflammatory cytokine induction in recent isolates maps to shared polymorphisms in the Cag PAI protein, CagY, while rod morphology in a subgroup of recent isolates mapped to eight mutations in three distinct helical cell shape determining (csd) genes. The presence of subgroups with unique genetic and phenotypic properties suggest complex selective forces and multiple niches within the stomach during chronic infection.

Helicobacter delphinicola sp. nov., isolated from common bottlenose dolphins Tursiops truncatus with gastric diseases.

Gastritis and gastric ulcers are well-recognized symptoms in cetaceans, and the genus Helicobacter is considered as the main cause. In this study, we examined the gastric fluid of captive common bottlenose dolphins Tursiops truncatus with gastric diseases in order to isolate the organisms responsible for diagnosis and treatment. Four Gram-negative, rod-shaped isolates (TSBT, TSH1, TSZ, and TSH3) with tightly coiled spirals with 2-4 turns and 2-6 bipolar, sheathed flagella, were obtained from gastric fluids of common bottlenose dolphins with gastric diseases. Phylogenetic analysis, based on 16S rRNA, atpA, and 60 kDa heat-shock protein (hsp60) genes, demonstrated that these isolates form a novel lineage within the genus Helicobacter. Analyses of 16S rRNA, atpA, and hsp60 gene sequences showed that isolate TSBT was most closely related to H. cetorum MIT99-5656T (98.5% similarity), H. pylori ATCC 43504T (76.7% similarity), and H. pylori ATCC 43504T (78.0% similarity), respectively. Type strains of Helicobacter showing resistance to 2% NaCl have not been reported previously; however, these novel isolates were resistant to 2% NaCl. Culture supernatant of some isolates induced intracellular vacuolization in mammalian cultured cells. These data, together with the different morphological and biochemical characteristics of the isolates, reveal that these isolates represent a novel species for which we propose the name Helicobacter delphinicola sp. nov. with type strain TSBT (= JCM 32789T = TSD-183T). Future studies will confirm whether H. delphinicola plays a role in lesion etiopathogenesis in cetaceans.

Gastrointestinal Disorders and Risk of First-Ever Ischemic Stroke.

BACKGROUND AND PURPOSE: Recent studies suggest that alteration of the normal gut microbiome contributes to atherosclerotic burden and cardiovascular disease. While many gastrointestinal diseases are known to cause disruption of the normal gut microbiome in humans, the clinical impact of gastrointestinal diseases on subsequent cerebrovascular disease remains unknown. We conducted an exploratory analysis evaluating the relationship between gastrointestinal diseases and ischemic stroke. METHODS: We performed a retrospective cohort study using claims between 2008 and 2015 from a nationally representative 5% sample of Medicare beneficiaries. We included only beneficiaries ≥66 years of age. We used previously validated diagnosis codes to ascertain our primary outcome of ischemic stroke. In an exploratory manner, we categorized gastrointestinal disorders by anatomic location, disease chronicity, and disease mechanism. We used Cox proportional hazards models to examine associations of gastrointestinal disorder categories and ischemic stroke with adjustment for demographics and established vascular risk factors. RESULTS: Among a mean of 1 725 246 beneficiaries in each analysis, several categories of gastrointestinal disorders were associated with an increased risk of ischemic stroke after adjustment for established stroke risk factors. The most notable positive associations included disorders of the stomach (hazard ratio, 1.17 [95% CI, 1.15-1.19]) and functional (1.16 [95% CI, 1.15-1.17]), inflammatory (1.13 [95% CI, 1.12-1.15]), and infectious gastrointestinal disorders (1.13 [95% CI, 1.12-1.15]). In contrast, we found no associations with stroke for diseases of the anus and rectum (0.97 [95% CI, 0.94-1.00]) or neoplastic gastrointestinal disorders (0.97 [95% CI, 0.94-1.00]). CONCLUSIONS: In exploratory analyses, several categories of gastrointestinal disorders were associated with an increased risk of future ischemic stroke after adjustment for demographics and established stroke risk factors.

Toll-like Receptor 5 Activation by the CagY Repeat Domains of Helicobacter pylori.

Helicobacter pylori (Hp) is an important human pathogen associated with gastric inflammation and neoplasia. It is commonly believed that this bacterium avoids major immune recognition by Toll-like receptors (TLRs) because of low intrinsic activity of its flagellin and lipopolysaccharides (LPS). In particular, TLR5 specifically detects flagellins in various bacterial pathogens, while Hp evolved mutations in flagellin to evade detection through TLR5. Cancerogenic Hp strains encode a type IV secretion system (T4SS). The T4SS core component and pilus-associated protein CagY, a large VirB10 ortholog, drives effector molecule translocation. Here, we identify CagY as a flagellin-independent TLR5 agonist. We detect five TLR5 interaction sites, promoting binding of CagY-positive Hp to TLR5-expressing cells, TLR5 stimulation, and intracellular signal transduction. Consequently, CagY constitutes a remarkable VirB10 member detected by TLR5, driving crucial innate immune responses by this human pathogen.

Association of toll-like receptors 2, 4, 9 and 10 genes polymorphisms and Helicobacter pylori-related gastric diseases in Saudi patients.

Purpose: Helicobacter pylori is one of the most prevalent human pathogens worldwide. However, the outcomes of H. pylori infection are markedly variable from asymptomatic mild lesion to malignant transformation. Many factors are suggested to influence these infection outcomes, including host immunity and genetic susceptibility. Toll-like receptors (TLRs) can recognise different microbial components and play an essential role in the mucosal immune response against H. pylori infection. Materials and Methods: The association between the common single nucleotide polymorphisms (SNPs) in the genes of TLR2, 4, 9 and 10 and H. pylori-related gastric diseases were investigated by molecular methods after the confirmation of H. pylori infection. The study included 210 patients in three groups; chronic gastritis (n = 90), peptic ulcer disease (PUD) (n = 75) and gastric carcinoma (n = 45). Results: The results showed a significant association between TLR4 SNPs (rs 4986790 and rs 4986791) and the presence of H. pylori infection, especially in chronic gastritis patient group. Furthermore, TLR9-rs352140 TT genotype was more prevalent among chronic gastritis patient group. TLR10-rs 10004195 TT genotype was found to be less prevalent among H. pylori-related chronic gastritis and PUD and was suspected to have a protective effect. TLR2 SNPs (rs3804099 and rs3804100) showed no significant statistical difference between H. pylori-infected patients and the controls. Conclusion: TLR genes polymorphisms may play a role in H. pylori infection susceptibility and may influence its outcomes; however, the ethnic and other factors may modify this effect.

Management of antibiotic-resistant Helicobacter pylori infection: current perspective in Iran.

Helicobacter pylori is a common gastric bacterial pathogen implicated in the pathogenesis of many digestive tract disorders. H. pylori infection prevalence has been reported alarmingly in Iran. A plethora of studies have been conducted to evaluate the efficiency of first-line and second-line eradication attempts in patients diagnosed with H. pylori infections in Iran. The present study, was evaluated the efficacy of first-line and second-line therapy in H. pylori infections in Iran. We aimed to consider the literature review of the various library and electronic databases (Science Direct, PubMed, and Google Scholar) until 2020. The frequency of bacterial resistance to tetracycline, ampicillin, trimethoprim, erythromycin, ofloxacin, and metronidazolewas found to be high in Iran, while the most effective antibiotics were clarithromycin, rifampin, rifampicin, tetracycline, amoxicillin, ciprofloxacin, levofloxacin, moxifloxacin, and azithromycin. The therapeutic choice for H. pylori eradication in Iran could be quadruple therapy using two antibiotics amoxicillin and metronidazole/clarithromycin for the first-line regimen, and a combination of furazolidone plus tetracycline/amoxicillin and bismuth plus proton pump inhibitor for the second-line regimen. Due to increased antibiotic resistance in our region, empirical therapy must be replaced by more targeted treatment based on antimicrobial drug resistance profiles obtained from patients. Although we limited our investigation on the H. pylori eradication regimens in Iran, the results can be generalized to any region as long as the patterns of resistance are the same.

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

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.