2003 Fiscal Year Final Research Report Summary
Studies on bioflim formation and survival mechanisms of Campylobacter species in foods
| Project/Area Number |
14560268
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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 |
Applied veterinary science
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| Research Institution | University of Miyazaki |
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Principal Investigator |
MISAWA Naoaki University of Miyazaki, Faculty of Agriculture, Associate Professor, 農学部, 助教授 (20229678)
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| Project Period (FY) |
2002 – 2003
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| Keywords | Campylobacter / Food / Biofilm / Survival / Gene |
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| Research Abstract |
We observed that Campylobacter jejuni strain 81-176, a strong slime producer, showed spreading and highly mucoid colonies on blood agar plates, and formed biofilm on the bottom of a glass flask after stationary cultivation in Brucella broth. The present study was performed to examine the mode of C. jejuni adherence to a smooth surface. When bacterial suspensions in Brucella broth were incubated in a microplate well, microcolonies were formed on the coverslip by 2 h after incubation. The microcolonies gradually grew and formed a biofilm of net-like connections by 6 h. Transmission electron microscopy indicated that massive amounts of extracellular material were masking the cell surface and bound ruthenium red, suggesting the presence of a poiysaccharide moiety. Scanning electron microscopy indicated that the flagella acted as bridges, forming a net-like connection between the organisms. To determine the genes associated with biofilm formation, several mutants were constructed from strain 81-176 by natural transformation-madiated allelic exchange. As aflagellate (flaAB and flbA) and flagellate but nonmotile (pflA and motA) mutants did not form a biofilm exhibited by the wild type strain even though capsular-like polysaccharide was expressed on the cell surface. In contrast, kpsM and peb1 mutants which lack capsular-like polysaccharide and a outer membrane protein, respectively, retained the ability of biofilm formation. These findings suggest that flagella-mediated motility but not capsular-like polysaccharide and PEB 1 protein is needed for biofilm formation in vitro.
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Research Products
(10 results)
