BACTERIAL RESPIRATORY-DISEASES OF POULTRY

Bacterial pathogens play an important role in causing respiratory dise ase in domestic poultry species. In many cases, the bacterial componen t of a respiratory disease colonizes the respiratory system only after a primary viral or environmental insult. Colonization of the airsacs of a chicken by Escherichia coli following an infectious bronchitis vi rus infection is an example of secondary bacterial invasion. In other cases, the bacterial component of the respiratory disease is the prima ry initiating cause of the disease. Examples of primary bacterial resp iratory disease are infectious coryza in chickens and fowl cholera in chickens and turkeys.