소화효소가 Helicobater pylori의 증식과 공포화독소 생성에 미치는 영향 = Effect of Digestive Enzymes on The Growth And Vacuolating Toxin Titer of Helicobater pylori

다국어 초록 (Multilingual Abstract)

Background Global high prevalence rate of Helicobacter pylori infection is well-known fact. However, a large discrepancies exist between the diagnostic data obtained by the PCR and culture method, because the coccoid form of H. pylori which represent the majority form in the biological samples are not viable in the standard BHI broth with 5% horse serum. The component parts of saliva and gastric juice acted as neither stimulator nor inhibitor to the growth of H. pylori remain unclear. Objective The purpose of this study was to evaluate the influence of amylase. pepsin, mucin, and lysozyme on the growth and vacuolating toxin production and titer of H. pylori in vitro.
Materials and Methods H pylori 13, 39, 46, 59, 72, 94, 98, and 125 strains were isolated from patients with gastric diseases. The digestive enzymes were inoculated in the 5% horse serum-BHI broth following final concentration of amylase (A: 0.25㎍/㎖), pepsin(P: 0.25㎍/㎖), mucin(M: 2.5㎍/㎖), and lysozyme(L: 1.5㎍/㎖). The vacuo-lating toxin titers of the culture supernatant were evaluated in the monolayer culture of RK-13 cells. Results The morphologic conversion from bacillary to horse-shoe to coccoid forms of H pylori was observed in the BHI broth containing 5% horse serum on day 5 culture. Half of H. pylori was evaluated from bacillary to coccoidal form on day 7 culture, most population of H. pylori was changed to coccoidal form on day 10 culture, and almost all H. pylori was changed to coccoidal form on day 14 culture. The growth of H. pylori 72, and 94 strains was increased in BHI broth containing each enzyme such as amylase, pepsin, mucin and mixture of two or three enzymes on day 5 and 7 culture. The growth of H. pylori 94 stains was increased in BHI broth containing each enzyme such as amylase, pepsin, mucin, and mixture of two or three enzymes on day 10 and 14 culture. The vacuolating toxin production of H. pylori strains was not influenced by the addition of amylase, pepsin, mucin and lysozyme or mixture of two or three enzymes. The neutralization of vacuolating toxin of H. pylori was not affected by the addition of amylase, pepsin mucin and lysozyme or mixture of two or three enzymes. Conclusion We found that coccoid forms of H. pylori were viable in the standard 5% horse serum BHI media in the presence of amylase, pepsin, mucin, and lysozyme. The present study demonstrates that gastric juice of the stomach supports the viability of H. pylori and that oral route of infection is a plausible hypothesis. This work also demonstrates that gastric environment may not provide a selective advantage for the toxigenic strains of H pylori.