Author
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Register, Karen |
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Submitted to: Pig Progress
Publication Type: Trade Journal Publication Acceptance Date: 4/10/2000 Publication Date: 6/1/2000 Citation: N/A Interpretive Summary: Technical Abstract: Whole cell vaccines for Bordetella bronchiseptica have been licensed for use in various countries for nearly 30 years. Colostral protection afforded by vaccinated sows clearly reduces the economic impact of this organism in swine production. Yet B. bronchiseptica remains widespread and can lead to suboptimal performance in older pigs, particularly when environmental and management conditions are not ideal. In a recent study, 96% of U.S. swine veterinary specialists surveyed reported using B. bronchiseptica vaccines, but only 38% reported them to be highly effective. Eighty-two percent of specialists from other countries worldwide also reported using vaccines, with just 55% indicating high efficacy. 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. Recent studies have provided the first definitive evidence that the dermonecrotic toxin is required for turbinate atrophy, and also required for development of lung lesions. Progress is likewise being made in several laboratories on the specific roles of other toxins and adhesins. The recent development of ribotyping as an epidemiologic tool provides a means to define inter- and intra-species transmission patterns of B. bronchiseptica. Continued progress in our understanding of the development and spread of disease caused by this bacterium will provide a basis for the design of novel vaccines and therapeutic interventions. |
