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.

幽门螺杆菌是革兰氏阴性螺旋状细菌病原体，是胃炎，消化性溃疡疾病的病原体，被归类为WHO WHO致癌物。尽管非洲的幽门螺杆菌感染率是世界上最高的，但胃癌的发生率却相对较低。关于与非洲幽门螺杆菌感染有关的其他症状以及与某些细菌毒力表型的关联知之甚少。我们在尼日利亚（NG）和南非（ZA）建立了研究地点网络，以概述流行病学情况。共分析了来自114名患者的220种分离株，并检查了118种不同的患者分离株中是否存在毒力因子cagA，vacA，dupA，它们的系统起源和对常用抗生素阿莫西林，克拉霉素，甲硝唑和四环素的抗性。我们报告说，来自尼日利亚和南非的幽门螺杆菌分离株在系统发育谱和毒力因子表达上有显着差异。VacA镶嵌非常密集，导致hpAfrica2菌株中出现m1-m2 vacA嵌合体以及频繁出现的s1m1和s1m2 vacA亚型。在尼日利亚患者中，与南非患者相比，胃病的诊断更为频繁，而且在两种国家中，对一种或多种抗生素具有抗药性的幽门螺杆菌分离株均屡见不鲜。