LEADER 00000nam  2200313   4500 
001    AAI3184729 
005    20061206115449.5 
008    061206s2005                        eng d 
020    9780542263118 
035    (UnM)AAI3184729 
040    UnM|cUnM 
100 1  Ledeboer, Nathan Allen 
245 10 Sticking around:  The role of fimbriae, cellulose, and 
       colanic acid in biofilm formation by Salmonella enterica 
       serovar Typhimurium on epithelial cell surfaces 
300    186 p 
500    Source: Dissertation Abstracts International, Volume: 66-
       08, Section: B, page: 4076 
500    Supervisor:  Bradley D. Jones 
502    Thesis (Ph.D.)--The University of Iowa, 2005 
520    Salmonella enterica serovar Typhimurium is a Gram-negative
       human pathogen that colonizes and invades the intestinal 
       mucosa. We and others have demonstrated that S. 
       Typhimurium attaches to and forms biofilm on eukaryotic 
       cell surfaces in a type 1 fimbriae-dependent manner. To 
       investigate the effect of biofilm on gene expression, we 
       compared gene expression between planktonic and biofilm 
       growth. Microarray results indicated that genes encoding 
       products involved in antibiotic resistance, central 
       metabolism, conjugation, intracellular survival, membrane 
       transport, and fimbrial biosynthesis are significantly 
       altered by growth in a biofilm. The identification of five
       fimbrial gene clusters was of particular interest because 
       their roles in adherence and intercellular adherence. 
       Mutations in the bovine colonization factor ( bcf), long 
       polar (lpf), plasmid encoded ( pef), thin aggregative 
       (csg), and Sth ( sth) fimbriae were constructed in S. 
       Typhimurium and the mutants were found to have various 
       biofilm phenotypes on plastic, HEp-2 cells and chicken 
       intestinal tissue. The pef and  csg mutants were defective
       for biofilm formation on each of the surfaces tested, 
       while the lpf mutant exhibited a complete loss in ability 
       to form biofilm on chicken intestinal tissue but only an 
       intermediate loss of biofilm formation on HEp-2 cells and 
       plastic. The bcf mutant formed increased biofilm on both 
       HEp-2 cells and chicken intestinal epithelium while the 
       sth mutant had no detectable biofilm defects 
520    In addition, previous work on Salmonella exopolysaccharide
       in biofilm indicated that the EPS composition can vary 
       based upon the substratum on which the bacterial biofilm 
       forms. We have investigated the role of genes important in
       the production of colanic acid and cellulose, common 
       components of EPS. A mutation in the colanic acid 
       biosynthetic gene, wcaM, disrupted biofilm formation on 
       HEp-2 cells and chicken intestinal tissue, although 
       biofilm formation on plastic was unaffected. A mutation in
       the cellulose biosynthetic gene, yhjN, disrupted biofilm 
       formation on HEp-2 cells, chicken intestinal epithelium, 
       and on plastic. Our data indicate that  Salmonella 
       attachment to, and growth on, eukaryotic cells represent 
       complex interactions that are facilitated by species of 
       EPS and fimbriae. Understanding these interactions is 
       likely to provide new insights for intervention strategies
       for Salmonella colonization and infection 
590    School code: 0096 
590    DDC 
650  4 Biology, Microbiology 
690    0410 
710 20 The University of Iowa 
773 0  |tDissertation Abstracts International|g66-08B 
856 40 |uhttp://pqdd.sinica.edu.tw/twdaoapp/servlet/