Novel roles for the AIDA adhesin from diarrheagenic Escherichia coli: cell aggregation and biofilm formation.
Diarrhea-causing Escherichia coli strains are responsible for numerous cases of gastrointestinal disease and constitute a serious health problem throughout the world. The ability to recognize and attach to host intestinal surfaces is an essential step in the pathogenesis of such strains. AIDA is a potent bacterial adhesin associated with some diarrheagenic E. coli strains. AIDA mediates bacterial attachment to a broad variety of human and other mammalian cells. It is a surface-displayed autotransporter protein and belongs to the selected group of bacterial glycoproteins; only the glycosylated form binds to mammalian cells. Here, we show that AIDA possesses self-association characteristics and can mediate autoaggregation of E. coli cells. We demonstrate that intercellular AIDA-AIDA interaction is responsible for bacterial autoaggregation. Interestingly, AIDA-expressing cells can interact with antigen 43 (Ag43)-expressing cells, which is indicative of an intercellular AIDA-Ag43 interaction. Additionally, AIDA expression dramatically enhances biofilm formation by E. coli on abiotic surfaces in flow chambers.
Sherlock
Orla
O
Centre for Biomedical Microbiology, BioCentrum-DTU, Technical University of Denmark, DK-2800 Lyngby, Denmark.
Schembri
Mark A
MA
Reisner
Andreas
A
Klemm
Per
P
D018830:Adhesins, Escherichia coli / Q000502:physiology*; D018441:Biofilms; D003001:Cloning, Molecular; D003967:Diarrhea / Q000382:microbiology*; D004926:Escherichia coli / Q000502:physiology*; D010861:Fimbriae, Bacterial / Q000502:physiology
D018830:Adhesins, Escherichia coli