Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: February 20, 2008
Publication Date: June 3, 2008
Citation: Uhlich, G.A., Bayles, D.O., Mosier, D.A. The CsgA and Lpp proteins affect motility and cell invasion in a strain of Escherichia coli O157:H7. Meeting Abstract. Technical Abstract: In Escherichia coli O157:H7 strain ATCC 43895, a guanine to thymine transversion in the csgD promoter created strain 43895OR. Strain 43895OR produces an abundant extracellular matrix rich in curli fibers, forms biofilm on solid surfaces, invades cultured epithelial cells, and is more virulent in a mouse model than strain 43895. We compared the formic acid-soluble proteins of strains 43895OR and 43895 by one dimensional SDS-PAGE. Proteins highly expressed in 43895OR, but not 43895, were identified by immunoblotting and mass spectrometry. A CsgA polyclonal antibody identified a 15-kDa protein as the curli subunit. A <10-kDa protein was identified from MALDI-TOF combined MS+MS/MS spectra as an Lpp homologue. Mutants of strain 43895OR with disruption of csgA, lpp, or both genes were created and tested for differences in motility and invasion of cultured HEp-2 cells. The results of this study show that Lpp affects swimming motility, CsgA affects swarming motility, and both are required for the invasion of cultured HEp-2 cells. However, CsgA but not Lpp expression is transcriptionally regulated under the conditions tested.