What respiratory illness can be caused by bacteria?

Lower Respiratory Infections: Bronchitis, Bronchiolitis and Pneumonia. Etiology: Causative agents of lower respiratory infections are viral or bacterial. Viruses cause most cases of bronchitis and bronchiolitis. In community-acquired pneumonias, the most common bacterial agent is Streptococcus pneumoniae.

Pneumonia is caused by bacteria in the lungs