Activation of the contact-phase system on bacterial surfaces--a clue to serious complications in infectious diseases

Nat Med. 1998 Mar;4(3):298-302. doi: 10.1038/nm0398-298.


Fever, hypotension and bleeding disorders are common symptoms of sepsis and septic shock. The activation of the contact-phase system is thought to contribute to the development of these severe disease states by triggering proinflammatory and procoagulatory cascades; however, the underlying molecular mechanisms are obscure. Here we report that the components of the contact-phase system are assembled on the surface of Escherichia coli and Salmonella through their specific interactions with fibrous bacterial surface proteins, curli and fimbriae. As a consequence, the proinflammatory pathway is activated through the release of bradykinin, a potent inducer of fever, pain and hypotension. Absorption of contact-phase proteins and fibrinogen by bacterial surface proteins depletes relevant coagulation factors and causes a hypocoagulatory state. Thus, the complex interplay of microbe surface proteins and host contact-phase factors may contribute to the symptoms of sepsis and septic shock.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacterial Proteins / metabolism
  • Blood Coagulation Disorders / etiology
  • Bradykinin / metabolism*
  • Enterobacteriaceae Infections / physiopathology*
  • Escherichia coli Infections / physiopathology
  • Female
  • Fever / etiology
  • Hypotension / etiology
  • Inflammation / etiology
  • Mice
  • Salmonella Infections, Animal / physiopathology
  • Shock, Septic / etiology*


  • Bacterial Proteins
  • Bradykinin