| Project/Area Number |
14570244
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Bacteriology (including Mycology)
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| Research Institution | KYORIN UNIVERSITY |
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Principal Investigator |
KAMIYA Shigeru Kyorin Univ. Sch. Med., Dept. Infect. Dis., Professor, 医学部, 教授 (10177587)
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| Co-Investigator(Kenkyū-buntansha) |
HANAWA Tomoko Kyorin Univ. Sch. Med., Dept. Infect. Dis., Research Associate, 医学部, 助手 (80255405)
OSAKI Takako Kyorin Univ. Sch. Med., Dept. Infect. Dis., Research Associate, 医学部, 助手 (90255406)
TAGUCHI Haruhiko Kyorin Univ. Sch. Med., Dept. Infect. Dis., Associate Professor, 医学部, 助教授 (20146541)
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| Project Period (FY) |
2002 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2003: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 2002: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | H. pylori / Quorum sensing / mutant / autoinducer / pathogenecity / ヘリコバクター・ピロリ / luxS / 病原因子 |
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| Research Abstract |
The luxS mutant (HP06) was generated by natural transformation of PCR-amplified luxS::cat gene from TN2 DNA fragment (kind gift from Drs Ogura & Berg) into H. pylori TK1402 strain. The production of AI-2 was evaluated by luminescence bioassay using Vibrio harveyi BB170 strain (kind gift from Dr Bassler). luxS gene of H. pylori could be expressed in E. coli, and genome sequence of the luxS from TK1402 strain was shown to have 96.1% and 96.2% homology to that of luxS of two reported strains 26695 and J99 strains, respectively.
Microbiological characteristics of 1uxS mutant HP06 strain was analyzed. The production of AI-2 by HP06 mutant was nearly one-hundredth of that by TK1402 parent strain. Although there was no significant difference in acid-resistance and adhesion activity to gastric epithelial cells between HP06 and TK1402 strains, the motility of HP06 was significantly weaker than that of TK1402. Approximately, 10^9CFU of H. pylori were orally inoculated into Mongolian gerbil (MGS/Sea, male, 8wk) twice with 24 hr-interval. H. pylori was detected by RT-PCR in 1 out of 5 HP06-infected gerbils at 1 month after infection. In contrast, H. pylori was detected by RT-PCR in all the TK1402-infected gerbils (n=5). Severe inflammation in gastric mucosa was observed only in TK1402-infected gerbil.
These results indicate that quorum sensing in H. pylori is important for colonization of H. pylori in gastric mucosa of Mongolian gerbil. The decrease of infectivity by luxS mutant was implied to be associated with the decreased motility.
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