Characteristics of Pneumonias Caused by Bacillus proteus

The clinical findings in six patients with pneumonias caused by either Proteus vulgaris, P. morganii, or P. mirabilis are described. The pathology of the single fatal case is presented. All had moderate degrees of chronic pulmonary disease, and most were alcoholics. Their pneumonias were heralded by a period of altered consciousness, often stupor or delirium tremens. The resulting aspiration pneumonias produced dense lobar consolidations with multiple abscesses. The involved lung was contracted in volume and when occupying an upper lobe; the trachea frequently was deviated toward this hemithorax. The illnesses required recognition and appropriate therapy before recovery ensued.