Pseudomonas aeruginosa expresses a lethal virulence determinant, the PA-I lectin/adhesin, in the intestinal tract of a stressed host: the role of epithelia cell contact and molecules of the Quorum Sensing Signaling System

Ann Surg. 2003 Nov;238(5):754-64. doi: 10.1097/01.sla.0000094551.88143.f8.


Objective: We have previously demonstrated that P. aeruginosa can have profound effects on the intestinal epithelial barrier via one of its virulence factors, the PA-I lectin/adhesin. The aims of the present study were to further characterize the interaction of P. aeruginosa and the intestinal epithelium using both in vitro and in vivo approaches.

Methods: In vitro assays examining the effect of bacterial growth phase, epithelial cell contact, and butanoyl homoserine lactone (C4-HSL), a quorum sensing signaling molecule know to affect various extracellular virulence factors in P. aeruginosa, on PA-I expression in P. aeruginosa were performed. In vivo studies were carried out by modeling catabolic stress in mice using a 30% surgical hepatectomy and direct introduction of P. aeruginosa and various virulence components into the cecum. The effect of this model on PA-I expression in P. aeruginosa was determined.

Results: Results demonstrated that PA-I expression in P. aeruginosa is affected by its phase of growth, its contact to the intestinal epithelium, and its exposure to the quorum sensing molecule, C4-HSL. Furthermore, data from the present study suggest that the PA-I lectin/adhesin of P. aeruginosa may be increased in vivo by local factors within the cecum of mice in response to surgical stress.

Conclusions: These data indicate that multiple factors present in the intestinal microenvironment of a stressed host may induce certain opportunistic pathogens to express key virulence factors leading to a state of lethal gut-derived sepsis.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adhesins, Bacterial / analysis
  • Adhesins, Bacterial / genetics*
  • Animals
  • Caco-2 Cells
  • Cecum / microbiology
  • Critical Illness
  • Disease Models, Animal
  • Electric Impedance
  • Epithelial Cells / physiology
  • Gene Expression Regulation, Bacterial / physiology*
  • Hepatectomy
  • Humans
  • Intestinal Mucosa / microbiology*
  • Lectins / analysis
  • Lectins / genetics*
  • Mice
  • Mice, Inbred BALB C
  • Pseudomonas aeruginosa / genetics
  • Pseudomonas aeruginosa / pathogenicity*
  • Sepsis / genetics
  • Sepsis / microbiology
  • Stress, Physiological / microbiology*
  • Virulence


  • Adhesins, Bacterial
  • Lectins
  • adhesin, Pseudomonas