Hua J, Ng H C, Yeoh K G, Ho B
Department of Microbiology, National University of Singapore, Republic of Singapore.
Helicobacter. 1999 Mar;4(1):28-32. doi: 10.1046/j.1523-5378.1999.09043.x.
Diversity of DNA among H. pylori strains isolated from different patients can serve as a useful marker for differentiating strains. DNA profiles of H. pylori obtained from sequential gastric biopsies were identical in most patients indicating that a given strain can persist from months to years. Patients colonized with more than two strains isolated mainly from different anatomical sites have been reported. This work examined whether the gastric antrum of patients with dyspepsia is colonized by single or multiple strains of H. pylori as well as the in vitro competition of different strains of H. pylori.
Two antral biopsy specimens from each of the 124 patients were cultured for H. pylori. DNA fingerprinting of H. pylori isolates was performed using random amplified polymorphic DNA (RAPD) analysis. To elucidate the possible interaction among H. pylori isolates, bacterial populations of two H. pylori strains cogrown in broth medium over 21 days were enumerated and DNA fingerprinting was compared.
A total of 58 patients showed the presence of H. pylori in both antral specimens, while five patients had H. pylori in only one of the two samples. These 58 patients were shown to harbor a single strain of H. pylori as analyzed by RAPD fingerprinting. In vitro studies of bacterial interaction of two different strains of H. pylori showed growth competition resulting in the predominance of a single strain.
The results support the concept that a single strain predominates in the gastric antrum site of patients studied.
从不同患者分离出的幽门螺杆菌菌株之间的DNA多样性可作为区分菌株的有用标记。在大多数患者中，从连续胃活检获得的幽门螺杆菌DNA图谱是相同的，这表明特定菌株可以持续存在数月至数年。已有报道称患者感染了主要从不同解剖部位分离出的两种以上菌株。这项研究检查了消化不良患者的胃窦是否被单一或多种幽门螺杆菌菌株定植，以及不同幽门螺杆菌菌株的体外竞争情况。
对124例患者中的每例患者采集两份胃窦活检标本进行幽门螺杆菌培养。使用随机扩增多态性DNA（RAPD）分析对幽门螺杆菌分离株进行DNA指纹分析。为了阐明幽门螺杆菌分离株之间可能的相互作用，对在肉汤培养基中共培养21天的两种幽门螺杆菌菌株的细菌群体进行计数，并比较DNA指纹。
共有58例患者的两份胃窦标本中均检测到幽门螺杆菌，而5例患者仅在两份样本中的一份检测到幽门螺杆菌。通过RAPD指纹分析显示，这58例患者感染的是单一菌株的幽门螺杆菌。对两种不同幽门螺杆菌菌株的细菌相互作用进行的体外研究表明，存在生长竞争，导致单一菌株占优势。
结果支持这样的观点，即在本研究的患者胃窦部位，单一菌株占主导地位。
