Responses of immune and nonimmune adult rhesus macaques (Macaca mulatta) to adenovirus SV-20.

Adenovirus SV-20 (ASV-20) was inoculated subcutaneously into adult rhesus macaques (Macaca mulatta), and various immunologic parameters were studied. Similar changes were observed in macaques that had anti-ASV-20 serum-neutralizing antibodies prior to inoculation and in those lacking detectable antibodies. There were absolute decreases in numbers of peripheral blood lymphocytes (PBL), erythrocyte-rosetting lymphocytes, complement-receptor lymphocytes, and Fc-receptor lymphocytes. These changes were most significant (P less than 0.05) on postinoculation days (PID) 3 and 7. Mitogenic responsiveness to concanavalin A, phytohemagglutinin, and pokeweed mitogen in cultured PBL from immune and nonimmune macaques was depressed on PID 3, 7, and 14. Ultraviolet-inactivated ASV-20 caused moderate suppression of phytohemagglutinin-induced mitogenesis when viral particles and lectin were added simultaneously to PBL cultures. Plasma cortisol (hydrocortisone) values were not significantly altered following inoculation of ASV-20. High titers of anti-ASV-20 antibody developed by PID 7 in nonimmune macaques, and previously immune macaques showed a booster effect in the same time period. Antibody titers were still increased 120 days after inoculation. There was no clinical evidence of an adverse effect of ASV-20 infection in these macaques.     

Transmissible gastroenteritis in neonatal dogs: experimental intestinal infection with transmissible gastroenteritis virus.

Fourteen neonatal dogs (4 through 11 days of age) were exposed orally to the Purdue strain of transmissible gastroenteritis (TGE) virus, and six dogs of similar age were noninoculated controls. Clinical signs of enteric disease did not develop. Both exposed and control dogs had normal fecal passages and appetite throughout the experiment. Jejunal epithelium from dogs euthanatized at 12, 24, 48, and 96 hours and at 10 days after exposure did not exhibit morphologic alterations detectable by light microscopy. Electron microscopic examination indicated that jejunal epithelial cells contained TGE viral particles as early as 12 hours after dogs were exposed. There were no apparent morphologic alterations or signs of desquamation of virus-infected cells, however. Results of pig transmission studies indicated that viable TGE virus was in jejunal tissue of the dogs as early as 12 hours and as late as 10 days after exposure to the virus.     

Antibiotic resistance and transferable antibiotica resistance Escherichia coli isolated from calves on a modern farm with therapeutic problems and unsatisfactory management conditions.

On a farm with therapeutic problems and unsatisfactory management conditions, the occurrence of antibiotic resistance and transferable antibiotic resistance has been studied in E. coli isolated from calves which were 5 and 30 days old. Strains with resistance to up to seven antibiotics as well as transferable resistance against up to five antibiotics were recorded. On an average, 4.2 strains with different patterns and 4.0 different strains with transferable resistance were isolated from each calf. The corresponding figures previously found for healthy control calves were 1.6 and 1.1 strains, respectively. Resistance and transferable resistance were most common against sulphonamide and penicillin.