Rudi J, Kolb C, Maiwald M, Kuck D, Sieg A, Galle P R, Stremmel W
Department of Medicine, University of Heidelberg, Germany.
J Clin Microbiol. 1998 Apr;36(4):944-8. doi: 10.1128/JCM.36.4.944-948.1998.
The vacuolating cytotoxin and the cytotoxin-associated protein, encoded by vacA and cagA, respectively, are important virulence determinants of Helicobacter pylori. Sixty-five H. pylori strains were isolated from dyspeptic patients (19 with peptic ulcer disease, 43 with chronic gastritis, and 3 with gastric cancer) and studied for differences in the vacA and cagA genes and their relationship to VacA and CagA expression, cytotoxin activity, and the clinical outcome of infection. By PCR, fifty-four (83.1%) of 65 strains had the vacA signal sequence genotype s1 and only 10 (15.4%) had the type s2. After primer modification, the vacA middle-region types m1 and m2 were detected in 24 (36.9%) and 41 (63.1%) strains, respectively. The combinations s1-m2 (31 [47.7%]) and s1-m1 (23 [35.4%]) occurred more frequently than s2-m2 (10 [15.4%]) (P = 0.01). No strain with the combination s2-m1 was found. All 19 patients with peptic ulcers harbored type s1 strains, in contrast to 32 (74.4%) of 43 patients with gastritis (P = 0.02). The vacA genotype s1 was associated with the presence of cagA (P < 0.0001), VacA expression (P < 0.0001), and cytotoxin activity (P = 0.003). The cagA gene was detectable in 48 (73.8%) of 65 isolates and present in 16 (84.2%) of 19 ulcer patients and 29 (67.4%) of 43 patients with gastritis (P = 0.17). The vacA genotypes of German H. pylori isolates are identical to those previously reported. H. pylori strains of vacA type s1 are associated with the occurrence of peptic ulceration and the presence of cagA, cytotoxin activity, and VacA expression.
分别由vacA和cagA编码的空泡毒素和细胞毒素相关蛋白是幽门螺杆菌重要的毒力决定因素。从消化不良患者中分离出65株幽门螺杆菌（19例患有消化性溃疡病，43例患有慢性胃炎，3例患有胃癌），研究vacA和cagA基因的差异及其与VacA和CagA表达、细胞毒素活性以及感染临床结果的关系。通过聚合酶链反应（PCR），65株菌株中有54株（83.1%）具有vacA信号序列基因型s1，只有10株（15.4%）具有s2型。引物修饰后，分别在24株（36.9%）和41株（63.1%）菌株中检测到vacA中间区域类型m1和m2。s1-m2（31株[47.7%]）和s1-m1（23株[35.4%]）的组合比s2-m2（10株[15.4%]）出现得更频繁（P = 0.01）。未发现s2-m1组合的菌株。所有19例消化性溃疡患者均携带s1型菌株，相比之下，43例胃炎患者中有32例（74.4%）携带该型菌株（P = 0.02）。vacA基因型s1与cagA的存在（P < 0.0001）、VacA表达（P < 0.0001）和细胞毒素活性（P = 0.003）相关。在65株分离株中有48株（73.8%）可检测到cagA基因，19例溃疡患者中有16例（84.2%）以及43例胃炎患者中有29例（67.4%）携带该基因（P = 0.17）。德国幽门螺杆菌分离株的vacA基因型与先前报道的相同。vacA s1型幽门螺杆菌菌株与消化性溃疡的发生以及cagA的存在、细胞毒素活性和VacA表达相关。
