Mechanisms of bacterial pathogenesis in respiratory processes: pasteurellosis

Abstract

Pasteurella multocida is a multispecies pathogen that causes serious diseases in wild and laboratory animals and in human beings. This bacteria is the etiologic agent of diseases such as fowl cholera in chicken and turkey, hemorrhagic septicemia in cattle, athrofic rhinitis in swine and infections in humans by cat and dog bites. This agent is responsible for annual losses of hundreds of millions of dollars in animal production, only in United States. In the rabbit P. multocida can be a virulent fatal pathogen inducing septicemia, pneumonia, chronic rhinitis, otitis as well as abscesses. In this species a respiratory syn-drome appears in which frequently Bortetella bronchi-septica is also isolated. However the role of each of these bacteria or some of their virulence factors, like LPS, in the induction of the disease has not been determined. P. multocida is a Gram negative cocobacilo with several identified virulence factors, like capsule, sialidasa, fila-mentous hemagglutinin, flagelum, neuraminidasa, some porins, dermonecrotic toxin, termolabil toxin (PMT), outer membrane proteins (OMP) and LPS. The lack of effective prevention and control of this type of diseases makes a research of the pathogenesis of the bacteria and its interactions with the host necessary.