The potential role of the Arthus and Shwartzman reactions in the pathogenesis of pneumonic pasteurellosis

Pneumonic pasteurellosis (PP) is an economically important disease in cattl e, sheep, and goats. Pasteurella haemolytica is commonly isolated from the severe fibrinopurulent pneumonia that characterize this respiratory syndrom e. During infection, the bacteria produce leukotoxin (LKT) and lipopolysacc haride (LPS), both potent inducers of inflammation. Nonetheless, it has als o been demonstrated that an exacerbated host's inflammatory response is res ponsible for the severe lung damage. Despite research in this field, the pa thogenesis of PP is still incomplete. Two classical models of acute inflamm atory response induced in laboratory animals, the Arthus and Shwartzman rea ctions, could explain the pathogenesis of the severe lung lesions that char acterize PP.