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.

Duodenal ulcer promoting gene (DupA), plasticity region genes and sigma factors in H. pyloristrains from Nigeria.

INTRODUCTION: Helicobacter pylori is a principal cause of gastric cancer. The aim of this study was to determine the prevalence and contribution of duodenal ulcer promoting gene A (dupA), the plasticity region genes and sigma factors in relation to their pathological expression of H. pylori infections in the Nigerian population. METHODOLOGY: Polymerase Chain Reaction was used to analyze a total of forty-nine H. pylori strains isolated from patients attending various endoscopic units in tertiary hospitals in Nigeria for complete dupA (G27 variant), jhp0917, jhp0918, other plasticity region genes jhp 914/917, jhp0914, jhp0940 and sigma factors. RESULTS: PCR results indicated that the prevalence of complete dupA (G27 variants), jhp0917, jhp0918 and other plasticity region genes jhp0914, jhp0914/0917 and jhp0940 in the H. pylori strains were 4%, 53%, 88%, 73%, 12% and 0% respectively. The prevalence values of the sigma factors were 96%, 92%, 80% for rpoN,  fliA and rpoD respectively. However, the endoscopic findings showed that erosion, normal mucosal, ulcer, hyperaemic stomach, mucosal atrophy and oedematous stomach in the patients where the H. pylori strains were isolated were 40.8%, 32.7%, 10.2%, 8.2%, 2.0% and 6.1% respectively. There was significant association between jhp0917, jhp914/917 and G27 variant and the endoscopic findings, while other plasticity genes showed no association with the endoscopic findings. CONCLUSION: These results suggest that the presence of jhp0917, jhp0914/917 and G27 variant could be used as marker to predict the pathological effect of severity in Nigeria patients with H. pylori infection.

Prevalence of Helicobacter pylori infection among dyspeptic patients with and without type 2 diabetes mellitus in Nigeria.

BACKGROUND: This multicenter study was undertaken to determine the prevalence of Helicobacter pylori (H. pylori) infection among dyspeptic patients with and without type 2 diabetes mellitus (T2DM). METHODS: Patients with dyspepsia were recruited from tertiary teaching hospitals, three in the South-West and one in the South-South regions of Nigeria, between November 2016 and August 2017. The participants had breath samples analyzed for H. pylori by the Urea Breath Test (UBT) following manufacturer's instructions. Dyspeptic patients who were diagnosed previously with T2DM were recorded. Crosstab using chi-square and correlation analyses were used to test (hypothesis) variables. RESULTS: The entire cohort included 471 dyspeptics, 19 (4%) of whom had T2DM. H. pylori infection was reported in 232/471 (49.3%) dyspeptics and 13/19 T2DM patients, without significant difference between diabetics and nondiabetics. The majority (84.6%) of those positive for UBT and T2DM were in the age group 52-71 years, while none was in the age group 72-91 years. There was no statistical significance (P>0.05) between the age group, UBT and T2DM positive. CONCLUSIONS: Our study showed that, in Nigeria, there is no difference in prevalence of H. pylori in dyspeptic patients with and without T2DM.

Clinical and Socio- Demographic Risk Factors for Acquisition of Helicobacter pylori Infection in Nigeria

Background: The aim of the study was to assess clinical and socio-demographic characteristics as well as prior drug usage as risk factors for Helicobacter pylori (H. pylori) infection in Nigeria. Methods: A total of 347 respondents were surveyed by assessing their clinical and socio-demographic characteristics in comparison with the non-invasive gold standard for H. pylori diagnosis, the urea breath test (UBT). Chi-square test and odds ratio analyses were conducted in order to assess if variables such as socio-demographic factors, drug intake, and history of ulcer/gastritis/ gastric cancer within the family significantly predicted test results. Results: A total of 130 (37.5%) respondents were positive for H. pylori by the UBT. Living with more than three people in an apartment and a history of ulcer/gastritis within the family were significantly associated with H. pylori (p ≤0.05), as well as current antibiotic intake (p ≤0.05). Nationality, stay outside Nigeria, level of education, main occupation, smoking and drinking habits, sources of drinking water, number of children and history of gastric cancer had no significant association with H. pylori infection (p ≥ 0.05). Conclusion: The results of the questionnaire revealed that most socio-demographic characteristics of the respondents had no significant association with H. pylori. Overcrowding, having siblings/parents with history of ulcer/gastritis as well as prior antibiotic usage had a significant association.