2005 Fiscal Year Final Research Report Summary
Quoram sensing and pathogenic mechanism in Helicobacter pylori infection
| Project/Area Number |
16590371
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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) |
TAGUCHI Haruhiko Kyorin Univ.Sch.Med., Dept.Infect.Dis., Associate Professor, 医学部, 助教授 (20146541)
OSAKI Takako Kyorin Univ.Sch.Med., Dept.Infect.Dis., Research Associate, 医学部, 助手 (90255406)
HANAWA Tomoko Kyorin Univ.Sch.Med., Dept.Infect.Dis., Research Associate, 医学部, 助手 (80255405)
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| Project Period (FY) |
2004 – 2005
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| Keywords | H.pylori / Quorum sensing / autoinducer / motility / biofilm |
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| Research Abstract |
Quorum sensing (QS) is a phenomenon of regulating bacterial genes through produced autoinducer (AI) according to cell density. Helicobacter pylori produces AI-2 which is encoded by lux S gene. In the present study, the pathological significance of QS in H.pylori was examined by using luxS-null mutant.
There was no significant difference in generation time between luxS-null mutant HPKY08 strain and its parental TK1402 strain. Although there was no significant difference in cell number in late-logarithmic and stationary phase between both strains, proliferation rate of HPKY08 strain tended to be slightly lower than that of TK1402 strain. Motility of HPKY08 strain was shown to be significantly lower than that of TK1402 strain in soft agar migration test and velocity measurement assay. In addition, in the presence of glucose (0.13-2.0%), the motility of HPKY08 strain was remarkably decreased. The motility of luxS-complemented strain HPKY21 recovered to the level of the parental TK1402 strain.
Colonization of HPKY08 strain was significantly inhibited in gastric mucosa of Mongolian gerbil compared to TK1402 strain, and gastric inflammation in HPKY08 strain infected gerbil was significantly milder than that in TK1402 infected gerbil. Electronmicroscopical examination indicated that complete flagella formed in both TK1402 and HPKY08 strains.
Decreased colonization by luxS-null mutant is implicated to be due to the decreased motility, but decreased growth rate and suppressed utilizing ability of glucose in luxS-null mutant might be involved in this phenomenon. These results obtained in our research indicate for the first time that luxS gene of H.pylori might be closely associated with motility and its colonization and that regulating of QS in H.pylori might be helpful for eradication therapy.
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Research Products
(14 results)
