| Research Abstract |
We have detected three types of cholesteryl glucosides (CGs) in H.pylofl (HP) cultured in a serum-supplemented medium. The structures of the CGs were cholesteryl glucoside (CGL), acylated CGL (CAG), and phosphatidyl CGL (CPG).
Firstly, we investigated bacterial growth in a serum-supplemented medium with shaking under microaerophlic conditIon using with a chamber (Concept plus, Ruskinn tech., UK). Under this condition, subculture and culture of HP can be done without exposing usual air.
We investigated the lipid, especially CGs, compositions of HP in each bacterial growth phase under the condition mentioned above. In CGs, CGL and CAG were detected at all growth phases. However, little of CPG was detected at exponential phase. CPG was detected In spiral form bacteria of stationary phase, and its content dramatically increased at declining phase (phase of coccoid formation), whereas the content of phosphatidyl ethanolarnine, main phosphoilpid of HP, was dramatically decreased at declining phase. The metabolism of phosphate was appeared to be dramaticaliy changed after stationary phase in HP.
We investigated the uptakes of sterols and those related compounds, and the synthesis of glucosides from those in a serum-free medium under the same condition mentIoned above. HP accumulated free cholesterol, ergosterol, stigmasterol, beta-sitosterol, and synthesize glucosides from those. However, HP did not accumulate cholesterol ester. Therefore, the structure of 3 beta-ol could be important for the accumulation of sterol. HP accumulated vitamin D3, cholecalciferol, but did not synthesize glucoside from it. For the synthesis of glucosides after the accumulation, the base structure of sterol would be important. Furthermore, vitamin D3 inhibited the growth of HP, and its MIC against HP In a serum-free medium was 12.5 mug/ml. The hydrophobic substances which are accumulated but not synthesized to glucosides such as vitamin D3 may inhibited the growth in HP.
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