A genus of gram-negative, nonmotile, nonsporulating, facultatively anaerobic coccobacillary to rod-shaped bacteria which are parasitic and often pathogens in many species of mammals, birds, and reptiles. It was named to honor Louis Pasteur in 1887. Genetic studies have shown that Pasteurella, together with Haemophilus and Actinobacillus, constitute a family, Pasteurellaceae.
The genus contains at least 10 species. Pasteurella multocida causes hemorrhagic septicemia in various mammals and fowl cholera, and is occasionally transmitted to humans, mainly in rural areas. Human pasteurellosis may include inflammation in bite and scratch lesions, infections of the lower respiratory tract and of the small intestine, and generalized infections with septicemia and meningitis. Pasteurella canis and P. stomatis may cause similar, though generally less severe, infections in humans after contact with domestic or wild animals. Although drug-resistant Pasteurella strains have been encountered, human Pasteurella infections are as a rule readily sensitive to the penicillins and a variety of other chemotherapeutic agents. See also Antibiotic; Drug resistance.