Interaction of Bacteroides fragilis and Bacteroides thetaiotaomicron with the kallikrein–kinin system

• DOI: 10.1099/mic.0.046862-0
• Publication Date: 2011-04-29T03:23:39Z
• Authors: Elizabeth C. Murphy; Matthias Mörgelin; Jakki C. Cooney; Inga-Maria Frick
• Keywords: Bacteroides thetaiotaomicron; Bacteroides fragilis; Bacteroidaceae; Prekallikrein

Many bacterial pathogens interfere with the contact system (kallikrein-kinin system) in human plasma. Activation of this has two consequences: cleavage high-molecular-mass kininogen (HK) resulting release potent proinflammatory peptide bradykinin, and initiation intrinsic pathway coagulation. In study, species Gram-negative anaerobic commensal organism Bacteroides, namely Bacteroides fragilis thetaiotaomicron, were found to bind HK fibrinogen, major clotting protein, from plasma as shown by immunoelectron microscopy Western blot analysis. addition, these capable activating at its surface leading a significant prolongation coagulation time also bradykinin. Members genus have been known act opportunistic outside gut, B. being most common isolate clinical infections, such intra-abdominal abscesses bacteraemia. The present results thus provide more insight into how cause infection.