Isolation and identification of infectious bovine rhinotracheitis virus in tissue culture.

SummaryAn agent producing a cytopathogenic effect has been isolated in bovine embryo tissue culture cells from upper respiratory tissues of cattle having the disease of infectious bovine rhinotracheitis. Lack of growth in bacteriological culture media, resistance to antibiotics such as penicillin and streptomycin, and ability to pass through fine porosity filters demonstrates that this agent is a virus. Reproduction of a disease in experimental cattle identical to that which occurs naturally, protection tests in cattle using tissue culture virus and infectious material from naturally occurring cases, as well as neutralization tests with serum obtained from naturally and experimentally infected cattle, show that this virus is the etiological agent of infectious bovine rhinotracheitis. Serum neutralization tests also indicate that viruses isolated from different parts of the country are closely related antigenically.