|Gentry-Weeks, C - CO STATE U., FT. COLLINS|
|Magyar, Tibor - VET. RES., BUDAPEST, HU|
Submitted to: Pig Veterinary Society International Congress Proceedings
Publication Type: Proceedings
Publication Acceptance Date: January 15, 1996
Publication Date: N/A
Technical Abstract: Bordetella bronchiseptica is associated with pneumonia and atrophic rhinitis in swine. An experimental model of B. bronchiseptica infection was developed in seven-day old colostrum-deprived, cesarean-derived pigs inoculated intranasally with either strain 4609 or B133. In the first experiment, five pigs/group were used; 6/group were used in the second. The pigs were housed in separate rooms and necropsied at 11 and 15 days post-inoculation (PI). Parameters included lethality; numbers of bacteria in nasal washings (3 and 15 days PI); numbers of bacteria/gram of turbinate, tonsil, trachea, and lung; degree of turbinate atrophy; gross and histologic lesions; and immunocytochemistry. Both strains of B. bronchiseptica colonized by 3 days PI according to nasal washings. One pig given 4609 died in the first experiment prior to day 11, and two died in the second. Two pigs given B133 died in the first experiment and none in the second. In general, trachea, lung, and turbinate had high numbers of bacteria (ranging from 10**4-10**6 cfu/g). Both strains caused only minimal to moderate turbinate atrophy but mild to marked pneumonia. By 15 days PI, there was moderate to marked peribronchial fibrosis, loss of cilia, and few adherent bacteria. This work characterizes a model of B. bronchiseptica infection and demonstrates that 4609 and B133 colonize the respiratory tract and induce pneumonia. The model is useful for comparison of virulence between strains of B. bronchiseptica.