连大卫+许艺飞+任文康+扶丽君+范平龙+操红缨+黄萍

[摘要]探讨广藿香醇对于幽门螺杆菌Helicobacter pylori脲酶活性的抑制及其相关基因的表达变化，为进一步研究廣藿香醇对幽门螺杆菌定植感染的影响奠定基础。培养幽门螺杆菌并采用革兰染色、快速尿素酶及PCR的方法鉴定后，在酸性条件（pH 5.3）和中性条件（pH 7.0）培养液中给予不同浓度的广藿香醇干预1 h，应用琼脂稀释法测定细菌的存活率；Berthelot显色法检测细菌的脲酶活性；RT-qPCR法检测细菌中ureA，ureB，ureE，ureH，ureI和nixA相关脲酶基因的表达变化。经过鉴定生长良好幽门螺杆菌在不同浓度的广藿香醇干预后， 细菌存活率没有明显变化；其脲酶活性出现了显著的下降；同时脲酶的相关基因ureA，ureB，ureE，ureH，ureI和nixA的表达均出现不同程度的降低。广藿香醇在酸性条件和中性条件下均可以抑制幽门螺杆菌脲酶的活性，可能与降低细菌脲酶相关的基因表达有关。

[关键词]幽门螺杆菌； 脲酶； 广藿香醇

[Abstract]To investigate the effect of patchouli alcohol on inhibiting Helicobater pylori urease activity， and its effect on expression levels of related genes， and lay the foundation for further research on the effect of patchouli alcohol on H. pylori colonization and infection. H. pyloriwas cultured and identified by gram staining， rapid urease test （RUT） and PCR method. Then agar dilution method was used to detect the bacterial survival after 1 h intervention by different concentrations of patchouli alcoholin the acidic （pH 5.3） and neutral （pH 7.0） conditions； berthelot method was used to detect urease activity and RT-qPCR method was used to detect the expression changes of ureA， ureB， ureE， ureH， ureI， and nixA related urease genes. The results showed that the survival rate of H. pyloriwas not significantly changed but the urease activity was obviously decreased after intervention by different concentrations of patchouli alcohol； meanwhile， the expression levels of ureA， ureB， ureE， ureH， ureI， and nixA were decreased to different degrees. Therefore， patchouli alcohol could inhibit H. pylori urease activity in both acidic and neutral conditions， and the mechanism may be related to down-regulation of urease gene expression.

[Key words]Helicobacter pylori； urease activity； patchouli alcohol

幽门螺杆菌（Helicobacter pylori）属于弯曲杆状的革兰阴性微需氧细菌，定植于宿主的胃部，是世界范围内最常见的传染性病原菌之一，全球有超过50%的人群感染。我国约有6亿以上人口感染，且有呈逐年上升的趋势^[1-2]。正常情况下人体的胃内的pH大约在1～2，因此极少有细菌能够在胃中存活下来，而H.pylori能够在此环境下生存主要是依靠其能够产生具有强大活性的脲酶^[3]，该种酶即使在胃液中也可以充分发挥分解胃液中少量的尿素而产生氨的作用，在幽门螺杆菌周围形成一片“氨云”，中和胃酸保护细菌不被胃酸杀灭^[4]。……