Pasteurella multocida pneumonia.

Pasteurella multocida, a gram-negative coccobacillus which colonizes the nasopharynx and gastrointestinal tract of many animals, is a well known cause of soft tissue infection after animal bites. Human infection can also occur after non-bite animal exposure, usually via inhalation of contaminated secretions. The respiratory tract is the second most common site of Pasteurella infection after soft tissue infection. Most patients with Pasteurella pulmonary infection are elderly with underlying lung disease, either COPD, bronchiectasis, or malignancy. The spectrum of disease includes pneumonia, tracheobronchitis, lung abscess, and empyema. Clinical features of Pasteurella respiratory tract infections are indistinguishable from other pathogens. A history of cat or dog exposure should alert the clinician to consider Pasteurella as a potential pulmonary pathogen in an elderly patient with chronic lung disease. The preferred drug for the treatment of Pasteurella infections is penicillin. Alternately, doxycycline is highly effective against P multocida.