Effect of equal concentration of Helicobacter pylori suspension on gastric mucosa in mice by different gavage methods / 中南大学学报(医学版)

ABSTRACT

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 group>B group>D group>A group>E 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 group>B group>D group>A group>E 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 group>D group>B group>A group>E 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.