摘要
目的用三种幽门螺杆菌菌株感染 C57BL/C 小鼠,观察不同菌株在小鼠胃内集落形成能力及感染后对小鼠胃粘膜组织学影响。方法:野生型 CPY3401株(CagA^+)与野生型 CPY3401株同源并去掉 CagA 的突变株(CagA^-)以及悉尼株(CagA^+),分别以0.5ml,10~9CFU/ml 细菌悬液通过胃管注入鼠胃。用 ELISA 法检测感染前后血清 IgG抗体水平。8周后处死小鼠,留取胃标本行组织病理检查。结果:(1)悉尼株和野生型株在鼠胃粘膜集落形成良好,突变株较差;(2)感染野生型株和悉尼株鼠胃粘膜固有层可见中到重度炎细胞浸润;(3)血清 IgG 抗体在感染后2周开始升高,5周达到高峰,2周、5周 t 值分别为悉尼株组7.41和17.44,野生型株组5.41和7.90,与对照组比较有极显著差异(P<0.01)。结论 CagA^+的悉尼株和野生型株在 C57BL/C 小鼠胃内集落形成良好,并引起明显的炎细胞浸润及产生高水平血清 IgG 抗体,对理解 CagA^+菌株在人胃感染中的致病作用及临床治疗有指导意义。C57BL/C 小鼠模型可用于 H.pylori 感染及相关疾病的研究。
Objectives To observe the differences of colonization and histopathology between CagA^+ strains and lacking CagA by three different strains infecting C57BL mice.Methods CPY3401 wild type strain (CagA+),CPY3401 (the isogenic CagA knockout mutant CagA^-,Sydney strain (Ca- gA^+)were used.The mice were administered orally with 0.5ml,10~9CFU/ml of above three bacte- rial suspension,respectively.Serum IgG antibodies were measured by ELISA.All mice were sacrificed at 8 weeks after iuculation and their stomach were removed for histopatholo- gic assay.Results The colonization of the bacteria was well in Sydney strain and mild type strain, and with wild to moderate infiltration by neutrophils and monocytes histologically.Only small nu- mer of organisms could be observed in the CagA^- strain group.The levels of serum IgG antibod- ies were the highest in Sydney and wild strains group,two and five weeks were 14.52±3.93,50. 45±7.91 and 10.74±3.22,33.24±10.93 respectively,there was significantly higher than the control group (P<0.01),there was no significant between CagA^- group and the control group. Conclusion There was a strong correlation between the CagA^+ and the bacterial colonization,the gastric mucosa inflammation,the serum IgG antibodies.The results in C57BL mice experimental study were helpful to understand the pathogenicity with CagA^+ strains in human body.It can be used to study H.pylori infection and associated diseases.
