Yakoob J, Fan X G, Peng X N, Hu G L, Zhang Z
Department of Infectious Diseases, Xiangya Hospital, Central South University, Changsha, Hunan, P. R. China.
Br J Biomed Sci. 2002;59(3):150-3. doi: 10.1080/09674845.2002.11783652.
Cytotoxin-associated protein (cagA) and the vacuolating cytotoxin (vacA) encoded by cagA and vacA genes are virulence determinants of Helicobacter pylori. In earlier studies among Chinese patients, all H. pylori strains were cagA-positive and vacAs1a/m2 type. Here, we determine the cagA, vacA and allele status of H. pylori strains isolated from patients with upper gastrointestinal symptoms in Changsha, China. Forty strains of H. pylori isolated from patients with peptic ulcer disease between March 1997 and August 1999 were recovered from storage at -80 degrees C and studied by the polymerase chain reaction (PCR) for cagA and vacA genotypes. cagA was positive in 75% of H. pylori isolates. Patients with peptic ulcer demonstrated cagA in 83% (15/18), compared with 68% (15/22) patients with superficial gastritis. vacAs1 allele was carried in 82.5% (33/40) isolates, of which 52.5% (21/40) were subtype vacAs1a/m2 and 17.5% (7/40) were subtype vacAs1b/m2.
细胞毒素相关蛋白（cagA）以及由cagA和vacA基因编码的空泡毒素（vacA）是幽门螺杆菌的毒力决定因素。在早期针对中国患者的研究中，所有幽门螺杆菌菌株均为cagA阳性且为vacAs1a/m2型。在此，我们确定了从中国长沙有上消化道症状的患者中分离出的幽门螺杆菌菌株的cagA、vacA及等位基因状态。1997年3月至1999年8月期间从消化性溃疡病患者中分离出的40株幽门螺杆菌菌株从-80℃保存状态复苏，并通过聚合酶链反应（PCR）研究其cagA和vacA基因型。75%的幽门螺杆菌分离株cagA呈阳性。消化性溃疡患者中83%（15/18）的幽门螺杆菌菌株cagA呈阳性，而浅表性胃炎患者中这一比例为68%（15/22）。82.5%（33/40）的分离株携带vacAs1等位基因，其中52.5%（21/40）为vacAs1a/m2亚型，17.5%（7/40）为vacAs1b/m2亚型。
