Microbiology ‐ Infectious Bronchitis Virus (IBV)

The Infectious Bronchitis Virus is a coronavirus in the order Nidovirales. Coronaviruses have an envelope surrounding an RNA genome and are divided into 3 main groups designated alpha, beta and gamma. IBV is a gamma coronavirus.

IB virus
Electron micrograph of Infectious Bronchitis virus particles Cook, J.K.A. (1983). Isolation of a new serotype of infectious bronchitis‐like virus from chickens in England. Veterinary Record, 112, 104‐105.


  • Pleomorphic, but mostly rounded, “enveloped” virus with spikes on its surface.
  • Contains a single stranded, positive sense RNA genome (see below) and codes for the viral polymerase (Replicase 1a/1ab), and structural proteins spike, envelope, membrane and nucleocapsid.
  • Family: Coronaviridae.
  • Rather fragile virus, infectivity of the virus is easily lost emphasizing the need to properly handle live vaccines.
  • Able to withstand pH ranges of pH 2 ‐ 12 depending on the strain, temperature and time of exposure.
  • Inactivated after 15 minutes at 56°C and after 90 minutes at 45°C.
  • Sensitive to most common disinfectants.
28kb genome
Schematic representation of the ∼28Kb genome of IBV showing coding regions for the viral proteins.