Bronchitis virus Illustration and Icon

Bronchitis virus. A stylized cross-sectional schematic shows an enveloped, coronavirus-like virion with prominent surface spikes and an internal helical nucleocapsid. In microbiology and virology, the illustration represents a virus (virion) within the family Coronaviridae (coronavirus, CoV), organized hierarchically as a lipid envelope bearing spike (S) glycoproteins, membrane (M) protein, and envelope (E) protein, surrounding a positive-sense single-stranded ribonucleic acid (ssRNA+) genome bound by nucleocapsid (N) protein. Functionally, the S glycoprotein mediates host-cell receptor attachment and membrane fusion, while the genomic RNA encodes structural and nonstructural proteins required for replication. Pathophysiologically, the virion targets the respiratory tract, particularly the bronchi, where infection can lead to bronchitis. The site is the airway epithelium of the host respiratory system; species is not specified in the image.