Author
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Register, Karen |
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Submitted to: International Pig Veterinary Society (IPVS)
Publication Type: Proceedings Publication Acceptance Date: 7/20/2000 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Bordetella bronchiseptica is a primary etiologic agent of atrophic rhinitis in swine and bronchopneumonia in young piglets. Numerous surveys demonstrate that it is also frequently found in nasal swabs and lung lesions of older pigs who may not necessarily exhibit overt clinical signs of respiratory disease. The impact of B. bronchiseptica under these circumstances depends upon specific environmental, management, and other factors unique to the operation in question. Other surveys reveal that pneumonia and atrophic rhinitis are the two most costly diseases for pork producers. Clinically apparent pneumonia in older swine often includes multiple infectious agents, with B. bronchiseptica playing a role as a predisposing or secondary pathogen. It may also contribute to Porcine Respiratory Disease Complex (PRDC), a more specifically defined condition that includes PRRSV, Mycoplasma hyopneumonia, and one or more additional bacterial or viral agents. Although whole-cell vaccines for B. bronchiseptica are widely used throughout the world, most veterinary specialists express dissatisfaction with the degree of protection they provide. One significant impediment to the development of improved vaccines has been a gap in our understanding of the identity and role of B. bronchiseptica virulence factors. The recent application of recombinant DNA techniques to previously unresolved questions concerning the pathogenesis of B. bronchiseptica in swine is beginning to provide a basis for the design of improved vaccines. Other recent studies are beginning to clarify the specific role of B. bronchiseptica in complicated respiratory disease, both as a predisposing factor and as a secondary pulmonary pathogen. |
