Pasteurella hemorrhagic septicemia infection

Pasteurella is a small, Gram-negative bacillus widely present in the respiratory tract and intestines of domestic and wild animals. When the host's resistance decreases, the disease can occur. Under normal circumstances, this bacterium is not present in the human body. Most patients develop the disease after being scratched or bitten by cats, dogs, and other animals, causing a disease mainly involving the skin. Skin lesions are related to the extent and depth of the bite wound. Initially, redness and swelling appear around the wound, rapidly expanding and ulcerating, with grayish-yellow bloody pus discharged from one or more sinus tracts. In some cases, the wound margins show obvious tenderness. If the wound is deep, it can cause periostitis and synovitis. Diagnosis can be confirmed based on medical history and laboratory isolation of slow-growing, Gram-negative bacilli. It is sensitive to penicillin, ampicillin, and tetracycline.