Acute Pasteurella multocida pneumonia.

Acute pneumonia caused by Pasteurella multocida appeared in two elderly patients. One patient had chronic obstructive lung disease and the other developed aspiration pneumonia after an episode of cardiac arrest. Pasteurella multocida was not isolated from the initial sputum cultures. The delay in recognizing the pathogen resulted in extension of the pneumonia and abscess formation in the patient with obstructive lung disease. Pasteurella multocida was isolated from a percutaneous transtracheal aspirate in both patients and from the blood of one. They recovered after treatment with a penicillin administered in higher than usual dosage over a period of several weeks.