Department of Microbiology, ShahreKord Branch, Islamic Azad University, Shahre Kord 166, Iran.
World J Gastroenterol. 2012 May 7;18(17):2105-11. doi: 10.3748/wjg.v18.i17.2105.
To compare genotype of Helicobacter pylori (H. pylori) isolated from saliva, dental plaques, gastric biopsy, and stool of each patient in order to evaluate the mode of transmission of H. pylori infection.
This cross-sectional descriptive study was performed on 300 antral gastric biopsy, saliva, dental plaque and stool samples which were obtained from patients undergoing upper gastrointestinal tract endoscopy referred to endoscopy centre of Hajar hospital of Shahrekord, Iran from March 2010 to February 2011. Initially, H. pylori strains were identified by rapid urease test (RUT) and polymerase chain reaction (PCR) were applied to determine the presence of H. pylori (ureC) and for genotyping of voculating cytotoxin gene A (vacA) and cytotoxin associated gene A (cagA) genes in each specimen. Finally the data were analyzed by using statistical formulas such as Chi-square and Fisher's exact tests to find any significant relationship between these genes and patient's diseases. P < 0.05 was considered statistically significant.
Of 300 gastric biopsy samples, 77.66% were confirmed to be H. pylori positive by PCR assay while this bacterium were detected in 10.72% of saliva, 71.67% of stool samples. We were not able to find it in dental plaque specimens. The prevalence of H. pylori was 90.47% among patients with peptic ulcer disease (PUD), 80% among patients with gastric cancer, and 74.13% among patients with none ulcer dyspepsia (NUD) by PCR assay. The evaluation of vacA and cagA genes showed 6 differences between gastric biopsy and saliva specimens and 11 differences between gastric and stool specimens. 94.42% of H. pylori positive specimens were cagA positive and all samples had amplified band both for vacA s and m regions. There was significant relationship between vacA s1a/m1a and PUD diseases (P = 0.04), s2/m2 genotype and NUD diseases (P = 0.05). No statically significant relationship was found between cagA status with clinical outcomes and vacA genotypes (P = 0.65). The evaluation of vacA and cagA genes showed 6 differences between gastric biopsy and saliva specimens and 11 differences between gastric and stool specimens.
Regard to high similarity in genotype of H. pylori isolates from saliva, stomach and stool, this study support the idea which fecal- oral is the main route of H. pylori transmission and oral cavity may serve as a reservoir for H. pylori, however, remarkable genotype diversity among stomach, saliva and stool samples showed that more than one H. pylori genotype may exist in a same patient.
比较每位患者唾液、牙菌斑、胃活检和粪便中分离的幽门螺杆菌（H. pylori）的基因型，以评估 H. pylori 感染的传播方式。
本横断面描述性研究于 2010 年 3 月至 2011 年 2 月期间对伊朗沙赫雷科尔德哈杰尔医院内镜中心就诊的 300 例接受上消化道内镜检查的患者的 300 例胃窦活检、唾液、牙菌斑和粪便样本进行了检测。最初，通过快速尿素酶试验（RUT）和聚合酶链反应（PCR）鉴定 H. pylori 菌株，以确定存在 H. pylori（ureC），并在每个标本中检测细胞毒素相关基因 A（cagA）和细胞毒素相关基因 A（cagA）基因的 vacA 基因分型。最后，使用卡方检验和 Fisher 确切检验等统计公式分析数据，以发现这些基因与患者疾病之间的任何显著关系。P<0.05 被认为具有统计学意义。
300 例胃活检样本中，77.66%经 PCR 检测证实为 H. pylori 阳性，而唾液中检出该菌 10.72%，粪便样本中检出 71.67%。我们未能在牙菌斑标本中发现它。通过 PCR 检测，消化性溃疡病（PUD）患者中 H. pylori 的患病率为 90.47%，胃癌患者为 80%，非溃疡性消化不良（NUD）患者为 74.13%。对 vacA 和 cagA 基因的评估显示，胃活检和唾液标本之间有 6 个差异，胃和粪便标本之间有 11 个差异。94.42%的 H. pylori 阳性标本 cagA 阳性，所有标本均扩增了 vacA s 和 m 区的扩增带。vacA s1a/m1a 与 PUD 疾病之间存在显著关系（P=0.04），s2/m2 基因型与 NUD 疾病之间存在显著关系（P=0.05）。cagA 状态与临床结果和 vacA 基因型之间无统计学显著关系（P=0.65）。对 vacA 和 cagA 基因的评估显示，胃活检和唾液标本之间有 6 个差异，胃和粪便标本之间有 11 个差异。
鉴于唾液、胃和粪便中分离的 H. pylori 基因型高度相似，本研究支持粪便-口腔是 H. pylori 传播的主要途径的观点，口腔可能是 H. pylori 的储库，但胃、唾液和粪便样本之间存在显著的基因型多样性表明，同一患者可能存在不止一种 H. pylori 基因型。
