Airborne-induced experimental Bordetella bronchiseptica pneumonia in Strain 13 guineapigs

Abstract

SummaryTo evaluate the efficacy of a commercial bacterial vaccine in protecting Strain 13 guineapigs against fatal Bordetella bronchiseptica pneumonia, it was necessary to establish the infectivity and disease pathogenesis induced by virulent organisms. When guineapigs were exposed to small-particle aerosols of varying concentrations of virulent B. bronchiseptica, a spectrum of disease was produced that ranged from inapparent illness to fulminant bronchopneumonia. Clinical signs began by day 4 after exposure, and were evidenced by anorexia, weight loss, respiratory distress and serous to purulent nasal discharge. Pathological alterations were limited to the respiratory system. Moribund animals exhibited a suppurative necrotizing bronchopneumonia and necrotizing tracheitis. In animals that survived the challenge, the bacteria were eliminated from the lungs by day 28 but continued to persist in the laryngeal area and the trachea. The median infectious dose and the median lethal dose were estimated to be 4 colony-forming units (CFU) and 1314 CFU respectively. These data suggest that the guineapig will be a valuable model system in which to study interactions between Bordetella species and host cells as well as to evaluate potential B. bronchiseptica immunogens.

Molecular Pathogenesis, Epidemiology, and Clinical Manifestations of Respiratory Infections Due toBordetella pertussisand OtherBordetellaSubspecies

“…Most experience over the last 90 years has been gained by the study of domesticated animals living in closed quarters. Transmission from animal to animal is by direct contact with respiratory secretions, fomites, and perhaps by aerosol (23,765). Porter et al have shown that the organism can grow in lakewater, which suggests that B. bronchiseptica may occur as a free-living organism (632,633).…”

Respiratory Diseases of Rodents and Rabbits

“…Whereas guinea pigs of all ages are susceptible to infection, young or stressed animals are more likely to show classic signs. The organism may be readily transmitted by the airborne route 85 and by direct contact or on fomites. Pets of other species, such as rabbits, cats, and dogs, may act as the source of infection for guinea pigs within a household.…”

Biology and Diseases of Guinea Pigs

“…Transmission is by fine particle aerosol onto the respiratory mucosa, by contaminated fomites, or by genital contact (Nakagawa et al, 1971;Trahan et al, 1987). The potential for transmission of Bordetella sp.…”