Covacci A, Falkow S, Berg D E, Rappuoli R
Dept of Molecular Biology, Immunobiological Research Institute of Siena (IRIS), Italy.
Trends Microbiol. 1997 May;5(5):205-8. doi: 10.1016/S0966-842X(97)01035-4.
Strains of Helicobacter pylori from patients with peptic ulcer disease and gastric cancer contain a 40-kb fragment of DNA that is not present in isolates from carriers with asymptomatic infections. The discovery of the cag pathogenicity island suggests that virulence has evolved by quantum leaps through the inheritance of one or more DNA insertions.
来自消化性溃疡病患者和胃癌患者的幽门螺杆菌菌株含有一段40千碱基对的DNA片段，而无症状感染携带者的分离菌株中不存在该片段。细胞毒素相关基因（cag）致病岛的发现表明，毒力是通过一个或多个DNA插入片段的遗传实现了跨越式进化。
