Pasteurellaceae

The Pasteurellaceae comprise a large family of Gram-negative bacteria. Most members live as commensals on mucosal surfaces of birds and mammals, especially in the upper respiratory tract. Pasteurellaceae are typically rod-shaped, and are a notable group of facultative anaerobes. Their biochemical characteristics can be distinguished from the related Enterobacteriaceae by the presence of oxidase, and from most other similar bacteria by the absence of flagella.

Bacteria in the family Pasteurellaceae have been classified into a number of genera based on metabolic properties, but these classifications are not generally accurate reflections of the evolutionary relationships between different species. Haemophilus influenzae was the first organism to have its genome sequenced and has been studied intensively by genetic and molecular methodologies. The genus Haemophilus is a notorious human pathogen associated with bacteremia, pneumonia, meningitis and chancroid. Other pathogenic members of the family Pasteurellaceae include Aggregatibacter, Mannheimia, Pasteurella, and Actinobacillus species.