Bordetella bronchiseptica Infections in Germ-Free Swine: An Experimental Pneumonia

Five-day-old germ-free piglets were challenged intranasally with Bordetella bronchiseptica. Infection with this agent consistently resulted in an acute bronchopneumonia characterized by broncholitis, hemorrhage, edema, necrosis, and epithelialization. In the absence of predisposing factors such as the additive or synergistic activity of a virus or mycoplasma, it was concluded that strains of B. bronchiseptica can initiate respiratory tract infections and in susceptible young swine can be a primary cause of pneumonia.