幽门螺杆菌空泡毒素基因分型

Gene typing of vacA for Helicobacter pylori

目的:探寻幽门螺杆菌(Hp)基因分型方法。方法:用自行设计的引物对16株临床分离Hp和2株标准菌 的空泡毒素基因vacA进行扩增,用7种限制性内切酶对基因扩增产物进行限制性片段长度多态性(RFLP)分析;对 18株HpVacA活性进行检测。结果:18株Hp的vacA扩增产物达2.7kb左右,但并不完全相同;HeaⅢ酶切电泳可将 18株Hp的vacA基因分为12种谱型。未发现与VacA表达相关的谱型。结论:vacA基因的PCR产物经HeaⅢ酶切 RFLP分型可作为Hp基因分型较理想的选择,但不能反映毒素活性的表达情况。

Aim: To supply a method of gene typing of vacA for Helicobacter pylori. Methods: vacA gene of 18 H.pylori strains were amplified by PCR. The amplifications were analyzed by restriction fragment length polymorphism(RFLP) with seven kinds of restriction endonucleases. VacA expression was determined using BHK cells cultured with H.pylori extract.Results:The vacA gene fragments amplified from 18 strains of H.pylori were different but all about 2.7 kb.The fragment digested with Hea Ⅲ could be classified into twelve patterns. The relationship between the PCR-RFLP pattern of vacA and VacA expressions was not found. Conclusion: It indicates that there is certain variability among vacA genes of H.pylori,and PCR-RFLP typing with Hea Ⅲ can be taken as an ideal index for gene typing of H.pylori.