Rudi J, Rudy A, Maiwald M, Kuck D, Sieg A, Stremmel W
Department of Medicine, and Institute of Microbiology, University of Heidelberg, Germany.
Am J Gastroenterol. 1999 Jun;94(6):1525-31. doi: 10.1111/j.1572-0241.1999.1138_a.x.
Our aim was to detect Helicobacter pylori (H. pylori) from gastric biopsies of 248 patients using a novel, polymerase chain reaction (PCR)-based methodology, which simultaneously facilitates the determination of H. pylori vacA genotypes and cagA gene.
A simple methodology for sample preparation was established and PCR was performed with primer systems for the 16S rRNA, vacA, and cagA genes, thus circumventing the need to culture H. pylori and to extract DNA from biopsy samples.
Infection with H. pylori was detected in 147 (59.3%) of 248 patients. The vacA signal sequence genotype s1 was present in 104 (81.3%) of 128 H. pylori-positive patients, and 24 (18.8%) patients had the genotype s2. The vacA middle region types m1 and m2 were detected in 46 (35.9%) and 79 (61.7%) patients, respectively. The combinations s1/m2 (43%) and s1/m1 (35.9%) were found more frequently than s2/m2 (18.8%). The cagA gene was detected in 75 (72.1%) of 104 H. pylori-positive biopsies with the vacA genotype s1. All 24 biopsies with the type s2 were cagA negative. Strains of the type vacA s1 were found in 97% of H. pylori-positive patients with peptic ulcer disease and were associated with the presence of the cagA gene, whereas 96% of the strains of the type vacA s2 were detected in patients who only had nonulcer dyspepsia.
Using a novel PCR-based methodology, H. pylori 16S rRNA gene, vacA genotypes, and cagA gene can now be rapidly detected directly in gastric biopsies with high accuracy. These data demonstrate that infection with H. pylori strains of the vacA s1 genotype and the cagA gene are more likely to result in peptic ulcer disease. Determination of vacA genotypes and cagA gene may contribute to the potential clinical identification of patients at different levels of risk.
我们的目标是使用一种基于聚合酶链反应（PCR）的新方法，从248例患者的胃活检组织中检测幽门螺杆菌（H. pylori），该方法同时有助于确定H. pylori的vacA基因型和cagA基因。
建立了一种简单的样本制备方法，并用针对16S rRNA、vacA和cagA基因的引物系统进行PCR，从而无需培养H. pylori和从活检样本中提取DNA。
248例患者中有147例（59.3%）检测到H. pylori感染。128例H. pylori阳性患者中有104例（81.3%）存在vacA信号序列基因型s1，24例（18.8%）患者为基因型s2。分别在46例（35.9%）和79例（61.7%）患者中检测到vacA中间区域类型m1和m2。发现组合s1/m2（43%）和s1/m1（35.9%）比s2/m2（18.8%）更常见。在104例vacA基因型为s1的H. pylori阳性活检组织中有75例（72.1%）检测到cagA基因。所有24例s2型活检组织cagA均为阴性。vacA s1型菌株在97%的幽门螺杆菌阳性消化性溃疡疾病患者中被发现，并与cagA基因的存在相关，而96%的vacA s2型菌株在仅患有非溃疡性消化不良的患者中被检测到。
使用基于PCR的新方法，现在可以直接在胃活检组织中快速、准确地检测H. pylori 16S rRNA基因、vacA基因型和cagA基因。这些数据表明，vacA s1基因型和cagA基因的幽门螺杆菌感染更有可能导致消化性溃疡疾病。vacA基因型和cagA基因的测定可能有助于对不同风险水平的患者进行潜在的临床识别。
