An infection of the tissues of the lungs that occurs principally in the smaller branches, called bronchioles, of the airways, or bronchial tubes. Bronchopneumonia, which is also called bronchial pneumonia, may be caused by bacteria such as pneumococci, staphylococci, and streptococci or by viruses such as the influenza virus. The disease may develop as a complication of a common cold or influenza. Some forms of bronchopneumonia are contagious.