Three cases of Pasteurella multocida infection in the respiratory tract

Pasteurella multocida (P. multocida) is well recognized as "normal flora" in the upper respiratory tract of cats, dogs and other animals. Recently, various infections due to P. multocida in human have been noted as pulmonary infections in the patients with chronic pulmonary diseases as well as skin abscesses or septicemia after an animal bite or scratch. We report here three cases of respiratory tract infections caused by P. multocida. The first two patients had acute exacerbation of bronchiectasis caused by P. multocida and the other patients with pulmonary emphysema developed pneumonia. These three patients improved by antibiotic therapy. In Japan, P. multocida respiratory tract infection is rare, but it may become more common in the future. Therefore, it seems to be important to take this pathogen into consideration in the management of chronic lung disease.