Pathogenesis of meningo-encephalitis produced in calves by infectious bovine rhinotracheitis herpesvirus

An investigation of the pathogenesis of meningo-encephalitis produced by the N569 strain of infectious bovine rhinotracheitis (IBR) herpesvirus, originally isolated from this disease in calves, showed that 4 to 5 days later intranasal instillation resulted in virus invading the central nervous system of 7 of 17 calves exposed. Virus appeared to pass to the brain from the nasal, tonsil and pharyngeal regions by the maxillary and mandibular branches of the trigeminal nerve. Entrance to the mid-brain was followed by generalization of virus infection throughout the brain and development of clinical meningo-encephalitis 10 to 11 days after infection. Epidural infection of 2 calves was followed by a fatal meningo-encephalitis in a calf 14 days after infection, but the route of invasion of the brain was not clear. Intravenous inoculation of 2 calves produced a viraemia of 2 to 3 days duration, the virus being associated mainly with leucocytes, but it did not result in meningo-encephalitis. Sporadic isolations of N569 virus in various organs provided indirect evidence of the occurrence of a transitory viraemia in 3 calves infected by the intranasal or epidural routes. Bovine nervous system tissues possessed receptors for IBR viruses isolated from rhinitis and vaginitis as well as for N569 virus

Studies on equine herpesviruses - II. Development of a complement fixation test antigen of cell culture origin for equine Herpes-1 (Rhinopneumonitis) virus and use in a microtitre system

A complement fixation (CF) antigen for equine herpes-1 (rhinopneumonitis) virus (EHV 1) of cell culture origin was studied, and an optimum method of preparation in a minimum volume of serum-free overlay fluid developed. Many chemical and physical treatments including fluorocarbon extraction, tweenether treatment, Carbowax concentration or ultracentrifugation (25,000 g) did not further improve the quality of this antigen. Inactivation (56°C for 30 minutes) of equine serum did not affect the CF antibody titre, but removed low levels of anti-complementary activity. The use of a diluent of low ionic strength (0.1 m) did not increase titres in the EHV 1-equine antibody CF system. This EHV 1 CF antigen of cell culture origin was used in a microtitre system and detected the development of antibodies in all of six young horses in Queensland following natural EHV 1 respiratory infection. Maximum serum titres (1/128) were reached 1-2 weeks after the onset of acute respiratory disease, then CF titres declined steadily but were still detectable after 12 months. Serum titres of 1/16-1/32 or higher indicated EHV 1 infection to have occurred within the previous 3-6 months

A Western-Blot to Detect Antibody to Avian Reovirus

Purified reoviruses RAM‐1 and 74/2 were combined and used as antigen. The Western blot detected antibodies to 16/16 avian reoviruses in sera from experimentally inoculated chickens, and to 6/7 reoviruses in contact sera from naturally infected chickens. The test was specific for avian reovirus and was more sensitive and specific than immunofluorescence