Major virulence factors, VacA and CagA, are commonly positive in Helicobacter pylori isolates in Japan
Major virulence factors, VacA and CagA, are commonly positive in Helicobacter pylori isolates in Japan
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DOI：
10.1136/gut.42.3.338
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发表时间：
1998-03-01
期刊：
影响因子：
24.5
通讯作者：
Omata, M
中科院分区：
文献类型：
--
作者：
Maeda, S;Ogura, K;Omata, M
背景-VacA和CagA蛋白是幽门螺杆菌的主要毒力因子。目的：检测日本分离的幽门螺杆菌（H pylori）菌株VacA和CagA蛋白的表达情况。方法：用抗重组VacA和CagA蛋白的特异性抗体，检测日本分离的68株H pylori菌株VacA和CagA蛋白的表达;在评价中还使用了空泡形成测定和vacA基因的基因分型。结果VacA和CagA蛋白分别在59/68株（87%）和61/68株（90%）中表达。空泡试验阳性57/68（84%）的菌株，表明大多数免疫VacA阳性菌株产生活性细胞毒素。表达CagA和空泡活性阳性（I型）的菌株感染的患病率是非常高的，54/68（79%），无论胃十二指肠状态的host. Conclusion-大多数幽门螺杆菌菌株在日本是空泡细胞毒素和CagA阳性，因此这些毒力因子不能被用作标记，以辨别发展严重的胃十二指肠病变的风险在主机。然而，空泡细胞毒素和CagA阳性菌株感染的高患病率可能有助于日本幽门螺杆菌感染的特点。
Background-VacA and CagA proteins have been reported to be major virulence factors of Helicobacter pylori. However, antibodies against these proteins are frequently found in the sera of Japanese patients regardless of their gastroduodenal status.Aim-To evaluate the expression of VacA and CagA proteins by H pylori strains isolated in Japan.Methods-By using specific antibodies raised against recombinant VacA and CagA proteins, the expression of VacA and CagA was evaluated in 68 H pylori strains isolated from Japanese patients; a vacuolating assay and genotyping of the vacA gene were also used in the evaluation. The results were analysed in relation to the gastroduodenal diseases of the hosts.Results-VacA and CagA proteins were Expressed in 59/68 (87%) and in 61/68 (90%) isolates respectively. The vacuolating assay was positive in 57/68 (84%) isolates, indicating that most immunologically VacA positive strains produced active cytotoxin. The prevalence of infection with strains expressing CagA and positive for vacuolating activity (Type I) was very high, 54/68 (79%), irrespective of the gastroduodenal status of the host.Conclusion-Most H Pylori isolates in Japan are positive for vacuolating cytotoxin and CagA, and thus these virulence factors cannot be used as markers to discern the risk of developing serious gastroduodenal pathologies in the hosts. However, the high prevalence of infection with strains positive for vacuolating cytotoxin and CagA may contribute to the characteristics of H pylori infection in Japan.