Immunoglobulin-mediated agglutination of and biofilm formation by Escherichia coli K-12 require the type 1 pilus fiber.

Journal Article

The binding of human secretory immunoglobulin A (SIgA), the primary immunoglobulin in the gut, to Escherichia coli is thought to be dependent on type 1 pili. Type 1 pili are filamentous bacterial surface attachment organelles comprised principally of a single protein, the product of the fimA gene. A minor component of the pilus fiber (the product of the fimH gene, termed the adhesin) mediates attachment to a variety of host cell molecules in a mannose inhibitable interaction that has been extensively described. We found that the aggregation of E. coli K-12 by human secretory IgA (SIgA) was dependent on the presence of the pilus fiber, even in the absence of the mannose specific adhesin or in the presence of 25 mM alpha-CH(3)Man. The presence of pilus without adhesin also facilitated SIgA-mediated biofilm formation on polystyrene, although biofilm formation was stronger in the presence of the adhesin. IgM also mediated aggregation and biofilm formation in a manner dependent on pili with or without adhesin. These findings indicate that the pilus fiber, even in the absence of the adhesin, may play a role in biologically important processes. Under conditions in which E. coli was agglutinated by SIgA, the binding of SIgA to E. coli was not increased by the presence of the pili, with or without adhesin. This observation suggests that the pili, with or without adhesin, affect factors such as cell surface rigidity or electrostatic repulsion, which can affect agglutination but which do not necessarily determine the level of bound immunoglobulin.

Full Text

Duke Authors

Cited Authors

  • Orndorff, PE; Devapali, A; Palestrant, S; Wyse, A; Everett, ML; Bollinger, RR; Parker, W

Published Date

  • April 2004

Published In

Volume / Issue

  • 72 / 4

Start / End Page

  • 1929 - 1938

PubMed ID

  • 15039312

International Standard Serial Number (ISSN)

  • 0019-9567

Language

  • eng

Conference Location

  • United States