Abstract

Fibrinogen is an important molecule in homeostasis and coagulation, besides its interaction with different host cells and participation in inflammatory process. Bacteria possessing fibrinogen-binding proteins can evade the immune host response by covering those molecules. Fibrinogen degradation can induce intravascular coagulation and depletion of fibrinogen produces bleeding in the affected host. Actinobacillus pleuropneumoniae is the causal agent of the porcine contagious pleuropneumonia, a respiratory disease of swine, characterized by fibrinohemorrhagic lung lesions. In this work, the identification of a 60 kDa secreted protein which is able to bind porcine fibrinogen, and the fibrinogen proteolytic cleavage by a secreted aminopeptidase are described. Fibrinogen binding proteins and fibrinogen proteolytic cleavage are important in the pathogenesis of Actinobacillus pleuropneumoniae.

Key words: Actinobacillus pleuropneumoniae, fibrinogen, protease, pathogenicity.