RESUMO
The induction of pneumonic pasteurellosis in guinea pigs (Cavia porcellus) was examined. Specific pathogen free male guinea pigs were anesthetized and a tracheostomy performed to introduce 10(5), 10(4) or 10(3) Pasteurella haemolytica-A1 into the left principal bronchus. The surgical site was closed with tissue adhesive and staples and the animals were monitored for signs of respiratory tract infection. Within 24 hours after inoculation they became depressed, anorectic, pyretic and dyspneic. Fibrinous pleuropneumonia with prominent areas of necrosis and hemorrhage was present. Pericardial effusion was a frequent finding. There was infiltration of the pleura and alveoli with degenerate heterophils and macrophages, a hyperplastic mesothelium and fibrin exudation on the pleura and within alveoli. Hemorrhage, congestion, consolidation, edema and fibrin exudation were prominent in the hilar region of the lungs. Bacterial colonies were evident in all airways. More bacteria were recovered from infected lungs than were inoculated (p less than 0.05) indicating P. haemolytica was actively multiplying in the lungs. Hematological and clinical chemistry data were consistent with fibrinous pneumonia, however, blood cultures were positive for P. haemolytica in 61% (11/18) of animals sampled. Examination of pneumonic pasteurellosis in guinea pigs may be useful in studying pathogenetic and pathological features applicable to bovine pneumonic pasteurellosis (shipping fever pneumonia).
Assuntos
Doenças dos Bovinos/microbiologia , Infecções por Pasteurella/veterinária , Pneumonia/veterinária , Doenças dos Roedores/microbiologia , Animais , Bovinos , Modelos Animais de Doenças , Cobaias , Masculino , Infecções por Pasteurella/patologia , Pneumonia/microbiologia , Pneumonia/patologia , Doenças dos Roedores/patologiaRESUMO
Gangrenous dermatitis caused by Corynebacterium ulcerans developed in 63 of 350 wild Richardson ground squirrels (Spermophilus richardsonii). Six squirrels died of toxemia and/or septicemia, but 57 responded to topical and parenteral administration of antibiotics. The epizo-otic was believed to be associated with fighting; infected and carrier ground squirrels most likely transmitted the C ulcerans through bite wounds. Individuals handling ground squirrels should be cautioned that C ulcerans may produce a diphtheria-like disease in human beings.
