目的探讨表达幽门螺杆菌（Hp）过氧化氢酶（KatA）的减毒鼠伤寒沙门氏菌疫苗株在防御Hp感染中的作用。方法构建表达KatA的重组质粒。用IPIG进行诱导表达，再将其转入减毒鼠伤寒沙门氏菌SL3261株中构建成口服活疫苗株，经口服免疫C57BL/6小鼠，并以Hp悉尼株进行攻击，用快速尿素酶试验和Hp定量培养粘膜中的Hp进行检测。结果SDS-PAGE的凝胶电泳上显示一条相对分子质量约79000的新生蛋白带，占细菌总蛋白的19%，并能与抗谷胱甘肽一转移酶（GST）抗体发生特异反应：动物实验结果显示：免疫小鼠能有效防御Hp的感染。结论表达KatA的减毒沙门氏菌疫苗株能诱导抗Hp保护免疫反应，有望在 Hp感染及其相关性疾病的防治中发挥积极作用。

目的建立适合不同研究需要的Hp动物模型。方法二级Wistar大鼠、二级C57BL、6小鼠及三级BALB/e小鼠40只，每种动物随机分为实验组（20只）及对照组（20只）。实验组动物接种Hp（Sydney strainl, SSI）菌液，小鼠0.4ml/只，大鼠1.5ml/只（约109/ml），连续5次，1周完成，而对照组则不作相应处理。距最后一次接种Hp的4、8、12及24周（BAIB/c16周）分别处死实验组及对照组动物各5只。取胃粘膜组织评价SSI在不同品系动物的定植及病理组织学改变。结果4周时所有实验组动物胃窦、胃体Hp检查均阳性，SSI主要定植于胃窦的胃小凹及腺腔，胃体较少；SSI定植量随感染时间的延长有增加的趋势，至24周时仍有明显定植；3种动物的Hp定植量比较，C57BL/6小鼠高于BALB/c小鼠和Wistar大鼠，对照组动物未有Hp定植。病理组织学检查：8周和24周Wistar大鼠、BALB/e和C57BL/6小鼠的胃窦及胃体出现经至中度慢性活动性胃炎改变，Wistar大鼠炎症细胞浸润的程度较BALB/e及C57BL/6小鼠重。对照组动物未见有炎症反应。结论 SSI Hp可长期定植于BALB/e、C57BL/6小鼠和Wistar大鼠腺胃，引起慢性活动性胃炎改变，上述模型的建立于Hp药物筛选、Hp疫苗的研究及Hp致病性的阐明具有重要的应用价值。

In previous studies we found that immunizing mice with a somicate of Helicobacter felis and adjuvant cholera toxin (CT; 10 ug) protected the animals against challenge with viable H. felis. The aim of this study was to determine whether a low dose of CT or its nontoxic B subunit (CTB) was effective as an adjuvant in Helicobacter oral vaceines. Significant protection against viable H. felis challenge was achieved in the amimals immunized with H. felis antigen plus the combination fo 0.5ug fo CT and 10ug fo CTB (96%), with H. felis antigen plus 0.5ug of CT (95)%, and with H. felis antigen plus 10 ug of CTB (83%), No protective effect was found in the mice immunized with either H. fells antigen alone or adjuvant CTB and CT alone. Twenty-six percent fo mice immunized with Helicobacter pylori antigen plus CT (10ug) were protected against H. fells challenge, comfimning the value of the model in predicting effects of immunization im humans. The observation that immunity can be induced with a montoxic adjuvant CTB opens the wsy for human studies with H. pylori waceines and is a further step along the road to effective strategies of prevention fo gastroduodenat diseases of major wirld signififcaace.