幽门螺杆菌 CagA 和 vacA 等位基因组合与胃十二指肠疾病。

CagA and vacA allelic combination of Helicobacter pylori in gastroduodenal disorders.

机构信息

Infectious and Tropical Diseases Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran; Department of Microbiology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.

Infectious and Tropical Diseases Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.

出版信息

Microb Pathog. 2018 Sep;122:144-150. doi: 10.1016/j.micpath.2018.06.023. Epub 2018 Jun 20.

DOI:10.1016/j.micpath.2018.06.023

PMID:29908307

Abstract

BACKGROUND

Allelic variation of the virulence genes, vacA and cagA, as the most important virulence associated genes play an important role in the pathogenesis of severe gastrointestinal disease.

OBJECTIVE

The aim of the present study was to identify the diversity of the virulence genes in patients with Gastric Cancer (GC), who were referred to the gastro-endoscopy unit of Imam Khomeini Hospital, Ahvaz Jundishapur University of medical science, Ahvaz, Iran.

METHODS

Gastric biopsy specimens from 301 patients suspected to gastrointestinal disorders, were analyzed for H. pylori using molecular and phenotypical methods (culture, and biochemical test (catalase, oxidase and urease tests)).

RESULTS

Among 201 PCR positive for H. pylori, using histopathological methods, 22 (10.9%) patients had GC. Presence of vacA gene in our H. pylori strains was 100% (201/201), while the most virulent vacA s1 allele was detected in 82.6% isolates, and the mid region vacA m1 was found in 39.8% isolates. The vacA s1/m1 genotype was the most virulent allelic combination in GC and Peptic Ulcer Disease (PUD) in 68.2% and 50%, respectively. The cagA gene was detected in 66.7% isolates. Among the cagA positive isolates, EPIYA-ABC motif was the most common motif in the GC (66.7%), PUD (55.6%) and Erosive Gastroduodenitis (EG) samples (55.2%), while EPIYA-ABCC was the most common motif (58.7%) in the Non-Ulcer Dyspepsia (NUD) samples. The vacA s1m1/cagA combination was detected in GC (73.3%) and PUD (51.9%), while vacA s1m2/cagA presented in the NUD and EG samples in 77.8% and 62.1%, respectively.

CONCLUSION

In this work, Western type (EPIYA-ABC and ABCC motifs) cagA, vacA s1m1 combinations have been demonstrated as the dominant genotype in the tested Ahvazian H. Pylori strains. Also the participation of cagA gene and vacA s1m1 genotype in development and severity of gastric disorder was well evident. Therefore, infection with H. pylori strain containing the cagA gene or the vacA s1m1 genotypes could be associated with increased risk of GC. This is the first study in our area that reports the high incidence and diversity of allelic combination of cagA and vacA genes in gastroduodenitis patients.

摘要

背景

毒力基因 vacA 和 cagA 的等位基因变异作为最重要的与毒力相关基因，在严重胃肠道疾病的发病机制中发挥着重要作用。

目的

本研究旨在鉴定伊朗阿瓦兹市库姆阿訇医科大学伊玛目礼萨医院胃肠内镜科就诊的胃癌（GC）患者中与毒力相关基因的多样性。

方法

采用分子和表型方法（培养和生化试验（过氧化氢酶、氧化酶和脲酶试验））分析了 301 例疑似胃肠道疾病患者的胃活检标本中幽门螺杆菌（H. pylori）的存在情况。

结果

在 201 例 PCR 阳性的 H. pylori 中，通过组织病理学方法，22 例（10.9%）患者患有 GC。我们的 H. pylori 菌株中 vacA 基因的存在率为 100%（201/201），而最具毒力的 vacA s1 等位基因在 82.6%的分离株中被检测到，而中间区域 vacA m1 在 39.8%的分离株中被检测到。在 GC 和消化性溃疡病（PUD）中，vacA s1/m1 基因型是最具毒力的等位基因组合，分别为 68.2%和 50%。cagA 基因在 66.7%的分离株中被检测到。在 cagA 阳性分离株中，EPIYA-ABC 基序是 GC（66.7%）、PUD（55.6%）和糜烂性胃炎（EG）样本（55.2%）中最常见的基序，而 EPIYA-ABCC 是 NUD 样本（58.7%）中最常见的基序。在 GC（73.3%）和 PUD（51.9%）中检测到 vacA s1m1/cagA 组合，而在 NUD 和 EG 样本中检测到 vacA s1m2/cagA，分别为 77.8%和 62.1%。

结论

在这项工作中，西方型（EPIYA-ABC 和 ABCC 基序）cagA、vacA s1m1 组合被证明是在测试的阿瓦兹幽门螺杆菌菌株中的主要基因型。此外，cagA 基因和 vacA s1m1 基因型在胃紊乱的发生和严重程度中起着重要作用。因此，感染含有 cagA 基因或 vacA s1m1 基因型的幽门螺杆菌菌株可能与 GC 的风险增加有关。这是我们地区首次报道胃十二指肠炎患者中 cagA 和 vacA 基因等位基因组合的高发生率和多样性。