Adhesion of type 1-fimbriated Escherichia coli to abiotic surfaces leads to altered composition of outer membrane proteins

Otto, J Norbeck, J Larsson, T Karlsson, KA Hermansson, M

J. Otto et al., Adhesion of type 1-fimbriated Escherichia coli to abiotic surfaces leads to altered composition of outer membrane proteins, J BACT, 183(8), 2001, pp. 2445-2453

55

INGLESE

Article

Microbiology

JOURNAL OF BACTERIOLOGY

0021-9193 → ACNP

183

8

2001

2445 - 2453

ISI

0021-9193(200104)183:8<2445:AOT1EC>2.0.ZU;2-5

Phenotypic differences between planktonic bacteria and those attached to ab iotic surfaces exist, but the mechanisms involved in the adhesion response of bacteria are not well understood. By the use of two-dimensional (2D) pol yacrylamide gel electrophoresis, we have demonstrated that attachment of Es cherichia coli to abiotic surfaces leads to alteration in the composition o f outer membrane proteins. A major decrease in the abundance of resolved pr oteins was observed during adhesion of type l-fimbriated E. coli strains, w hich was at least partly caused by proteolysis. Moreover, a study of fimbri ated and nonfimbriated mutants revealed that these changes were due mainly to type 1 fimbria-mediated surface contact and that only a few changes occu rred in the outer membranes of nonfimbriated mutant strains. Protein synthe sis and proteolytic degradation were involved to different extents in adhes ion of fimbriated and nonfimbriated cells. While protein synthesis appeared to affect adhesion of only the nonfimbriated strain, proteolytic activity mostly seemed to contribute to adhesion of the fimbriated strain. Using mat rix-assisted laser desorption ionization-time of flight mass spectrometry, six of the proteins resolved by 2D analysis were identified as BtuB, EF-Tu, OmpA, OmpX, Sip, and TolC. While the first two proteins were unaffected by adhesion, the levels of the last four were moderately to strongly reduced. Based on the present results, it may be suggested that physical interactio ns between type 1 fimbriae and the surface are part of a surface-sensing me chanism in which protein turnover may contribute to the observed change in composition of outer membrane proteins. This change alters the surface char acteristics of the cell envelope and may thus influence adhesion.