The burden of Helicobacter pylori-induced gastric cancer varies based on predominant H. pylori population in various geographical regions. Vietnam is a high H. pylori burden country with the highest age-standardized incidence rate of gastric cancer (16.3 cases/100,000 for both sexes) in Southeast Asia, despite this data on the H. pylori population is scanty. We examined the global context of the endemic H. pylori population in Vietnam and present a contextual and comparative genomics analysis of 83 H. pylori isolates from patients in Vietnam. There are at least two major H. pylori populations are circulating in symptomatic Vietnamese patients. The majority of the isolates (~ 80%, 66/83) belong to the hspEastAsia and the remaining belong to hpEurope population (~ 20%, 17/83). In total, 66 isolates (66/83) were cagA positive, 64 were hspEastAsia isolates and two were hpEurope isolates. Examination of the second repeat region revealed that most of the cagA genes were ABD type (63/66; 61 were hspEastAsia isolates and two were hpEurope isolates). The remaining three isolates (all from hspEastAsia isolates) were ABC or ABCC types. We also detected that 4.5% (3/66) cagA gene from hspEastAsia isolates contained EPIYA-like sequences, ESIYA at EPIYA-B segments. Analysis of the vacA allelic type revealed 98.8% (82/83) and 41% (34/83) of the strains harboured the s1 and m1 allelic variant, respectively; 34/83 carried both s1m1 alleles. The most frequent genotypes among the cagA positive isolates were vacA s1m1/cagA + and vacA s1m2/cagA + , accounting for 51.5% (34/66) and 48.5% (32/66) of the isolates, respectively. There are two predominant lineages of H. pylori circulating in Vietnam; most of the isolates belong to the hspEastAsia population. The hpEurope population is further divided into two smaller clusters.

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越南南部的地方性幽门螺杆菌群有东南亚和欧洲的起源

由幽门螺杆菌引起的胃癌的负担因不同地理区域的主要幽门螺杆菌人群而异。尽管有关 H. pylori 人口的数据很少，但越南是东南亚 H. pylori 负担高的国家，胃癌的年龄标准化发病率最高（男女均为 16.3 例/100,000）。我们研究了越南地方性幽门螺杆菌人群的全球背景，并对来自越南患者的 83 株幽门螺杆菌分离株进行了背景和比较基因组学分析。至少有两个主要的幽门螺杆菌群体在有症状的越南患者中传播。大多数分离株（~80%，66/83）属于 hspEastAsia，其余属于 hpEurope 种群（~20%，17/83）。总共有 66 个分离株 (66/83) 为 cagA 阳性，64 个是 hspEastAsia 分离株，2 个是 hpEurope 分离株。对第二个重复区域的检查表明，大多数 cagA 基因是 ABD 型（63/66；61 个是 hspEastAsia 分离株，两个是 hpEurope 分离株）。其余三个分离株（均来自 hspEastAsia 分离株）是 ABC 或 ABCC 型。我们还检测到来自 hspEastAsia 分离株的 4.5% (3/66) cagA 基因含有 EPIYA 样序列，在 EPIYA-B 片段处为 ESIYA。vacA 等位基因类型的分析显示，98.8% (82/83) 和 41% (34/83) 的菌株分别含有 s1 和 m1 等位基因变体；34/83 携带两个 s1m1 等位基因。cagA 阳性分离株中最常见的基因型为 vacA s1m1/cagA + 和 vacA s1m2/cagA + ，分别占分离株的 51.5% (34/66) 和 48.5% (32/66)。H 有两个主要谱系。在越南传播的幽门螺杆菌；大多数分离株属于 hspEastAsia 种群。hpEurope 人口进一步分为两个较小的集群。