| Project/Area Number |
17591098
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Pediatrics
|
|---|
| Research Institution | Kagoshima University |
|---|
Principal Investigator |
NISHI Junichirou Kagoshima University, Medical and Dental Hospital, Senior Assistant Professor (40295241)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
NOMURA Yuichi Kagoshima University, Graduate School of Medical and Dental Sciences, Associate Professor (90237884)
前野 伸昭 鹿児島大学, 大学院・医歯学総合研究科, 助手 (20305113)
|
|---|
| Project Period (FY) |
2005 – 2007
|
| Project Status |
Completed (Fiscal Year 2007)
|
| Budget Amount *help |
¥3,900,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥300,000)
Fiscal Year 2007: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2006: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2005: ¥1,500,000 (Direct Cost: ¥1,500,000)
|
|---|
| Keywords | prolonged infection / biofilm / Enteroaggregative E. coli / AatA / TolC / H. influenzae / MRSA / agr / 遺伝子ノックアウト / shf / 転写因子 / EAEC / dispersin / 付着因子 / H.influenzae |
|---|
| Research Abstract |
Biofilm formation and related pathogenic genes of clinical isolates from children with prolonged infections were investigated. Enteroaggregative Escherichia coli (EAEC) is an emerging enteric pathogen in both developing and industrialized countries. AatA, an outer-membrane protein that is a homolog of E. call To1C, facilitates the export of the dispersin protein Aap. The structure-function analysis of AatA demonstrated that three nonpolar amino acids at positions 381-383 (Phe-Leu-Leu) were required for the activity. We investigated the role of To1C in the virulence of EAEC, and showed that To1C promotes aggregation and adhesion of EAEC by secreting an assumed humoral factor. In addition, we demonstrated that the shf gene on the pathogenic plasmid is required for the firm biofilm formation of EAEC. Adhesins such as HifA, HMW1/2, Ilia, Hap of nontypable Haemophilus influenzae were investigated in clinical isolates from children. We concluded that HifA and'Hia are associated with bioflm formation, and that biofilm formation plays an important role in recurrent respiratory infections. Biofilm formation and the accessory gene regulator (agr) typing of MRSA strains were investigated. The biofilm index and the incidence of agr-2 in the infection group were significantly higher than those in the carrier group, suggesting that biofilm formation and agr type are associated with nosocomial MRSA infections. These results are considered to be significant for further studies to develop the new therapy for prolonged infections associated with biofilm in children.
|
