A study of lung lesions in asymptomatic rabbits naturally infected with B. bronchiseptica

A histological study of lungs performed in 40 rabbits carrying a naturally acquired subclinical B. bronchiseptica infection revealed chronic inflammatory pulmonary lesions in 38 rabbits, B. bronchiseptica was the only agent consistently isolated from lungs. Pasteurella spp. was not isolated from any animal. B. bronchiseptica infected rabbits frequently displayed changes characterized by a simultaneous occurrence of focal chronic interstitial pneumonia, vascular and perivascular infiltration of monocytes and lymphoid cells, and inflammation ofbronchi and bronchioli

Chronic inflammatory lung lesions in rabbits free of known respiratory pathogens

Chronic inflammatory lung lesions were studied in 58 purpose bred, clinically healthy rabbits that were found negative for Bordetella branchiseptica, Pasleurel/a multocida, Toxoplasma gondii, Encephalitozoon cuniculi, and lung worms. The changes found consisted of focal chronic interstitial pneumonia and chronic bronchitis and bronchiolitis, which were frequently associated with perivascular infiltrations of mononuclear leukocytes and vasculitis involving small lung vessels. The etiology of these alterations remains unknown

Five month persistence of Helicobacter pylori infection in guinea pigs

Seven Dunkin-Hartley guinea pigs were infected with the Sydney strain of H. pylori (SS1). Gastric histopathology was evaluated and serum antibody response to H. pylori cell-surface proteins was analysed by enzyme immunoassay (EIA) and immunoblot. Tissue and faecal samples from five control animals were analysed for the presence of naturally occurring Helicobacter spp. infection by culture and Helicobacter genus-specific PCR. The H. pylori infection persisted for 5 months, in most animals accompanied by a histologically severe antral gastritis, exhibiting focal degeneration and necrosis of gastric crypt epithelium. Increased numbers of mitotic figures were observed in the gastric epithelium, indicating a regenerative process. Infected animals displayed specific antibodies towards H. pylori cell-surface proteins in immunoblot, whereas EIA was of dubious value creating false-positive results. Serum complement C3 and cholesterol levels appeared to be elevated in infected animals. Helicobacter spp. infection was not detected in the control animals. The persistent infection, accompanied by severe gastritis and a prominent serum antibody response, and the apparent absence of a natural Helicobacter spp. infection makes the guinea pig model useful in H. pylori research