[Effect of equal concentration of Helicobacter pylori suspension on gastric mucosa in mice by different gavage methods]

To investigate the effects of equal concentration of Helicobacter pylori suspension on gastric mucosal infection in mice by different gavage methods. Methods: Six-week-old male C57BL/6 mice were infected by a suspension of Brucella broth containing the same amount of NCTC11637 Helicobacter pylori suspension by A, B, C, and D methods. For method A, the mice were intragastrically administered with Helicobacter pylori suspension (0.2 mL per mouse), once two day for 5 times; for method B, the mice were intragastrically administered with Helicobacter pylori (0.2 mL per mouse) once a day for 5 times; for method C, the mice were perfused with 0.4 mL per mouse of Helicobacter pylori suspension on the first day, then once a day and 0.2 mL per mouse for 3 times; for method D, the mice were administrated with 0.4 mL per mouse Helicobacter pylori suspension on the first day, 0.2 mL per mouse every other day for 3 times. For method E, the mice received equal amounts of normal saline. The mice were killed at 2, 4, and 6 weeks after gavage. The gastric mucosa was detected by rapid urease test for Helicobacter pylori infection, and gastric mucosa was taken for HE staining to observe the degree of infection. Results: After 2 weeks of gavage, the infection rates of the mice in A, B, C, and D group were 33.3%, 50.0%, 66.7%, and 33.3%, respectively. The degree of inflammation infection was as following order: C groupB groupD groupA groupE group. The infection rates of mice after 4 weeks of gavage in the A, B, C, and D groups were 50.0%, 83.3%, 83.3%, and 66.7%, respectively. The degree of inflammation infection was as following order: C groupB groupD groupA groupE group. After 6 weeks of gavage, the infection rate in A, B, C, and D groups was 100%, while the degree of inflammation infection was as following order: C groupD groupB groupA groupE group. Conclusion: At the acute stage of Helicobacter pylori infection, different gavage methods show different infection rates in mice, and the degree of inflammation is different. At the chronic stage, different gavage methods display the same infection rate in mice with different degree. The gavage method that 0.4 mL Helicobacter pylori suspension on the first day, then once a day and 0.2 mL for 3 times is most conducive to Helicobacter pylori colonization in the gastric mucosa of mice. This method can induce the the most seriou inflammatory infection and is beneficial to the successful establishment of the Helicobacter pylori infection model.目的：探讨等量幽门螺杆菌不同灌胃方法对小鼠幽门螺杆菌的感染率及小鼠胃黏膜感染幽门螺杆菌程度的影响。方法： 将含等量NCTC11637幽门螺杆菌的布氏肉汤混悬液通过A，B，C，D 4种方法感染6周龄的雄性 C57BL/6小鼠。A方法用幽门螺杆菌悬液0.2 mL/只灌胃小鼠，隔天1次，共5次。B方法用幽门螺杆菌悬液0.2 mL/只灌胃小鼠，每天1次，连续5次。C方法第1天用幽门螺杆菌悬液灌胃小鼠0.4 mL/只，以后连续3 d每天灌胃1次，每次0.2 mL/只。D方法第1天用幽门螺杆菌悬液灌胃小鼠0.4 mL/只，以后隔天灌胃1次，每次0.2 mL/只，共3次。E方法用等量生理盐水灌胃小鼠。灌胃后第2，4，6周处死小鼠，其胃黏膜组织用快速尿素酶检测是否有幽门螺杆菌感染，并取胃黏膜组织进行HE染色，观察胃黏膜组织的感染程度。结果：2周后A，B，C，D组小鼠的感染率分别为33.3%， 50.0%，66.7%，33.3%；炎症的感染程度C方法B方法D方法A方法E方法。4周后A，B，C，D组小鼠的感染率分别为50.0%，83.3%，83.3%，66.7%；炎症的感染程度C方法B方法D方法A方法E方法。6周后A，B，C，D组小鼠的感染率均为100%；炎症的感染程度C方法D方法B方法A方法E方法。结论：在幽门螺杆菌急性感染期，灌胃方法不同小鼠的感染率不同，炎症程度不同；在幽门螺杆菌的慢性感染期，灌胃方法不同小鼠的感染率相同，感染的炎症程度不同。采用第1天灌0.4 mL，以后连续3 d每天1次，0.2 mL/次的灌胃方法最有利于幽门螺杆菌在小鼠胃黏膜定植，感染炎症程度最严重，有利于幽门螺杆菌感染模型的成功建立。.