Pasteurellaceae comprise a large and diverse family of Gram-negative bacteria, with members ranging from important pathogens such as Haemophilus influenzae to commensals of the animal and human mucosa. Information on the biology of these organisms has mushroomed in recent years, driven by the development of novel genetic and molecular methodologies. Since 1995, the family has been expanded from three genera to the current thirteen through the use of new genetic-based classification and identification technologies. Many members of the Pasteurellaceae family make excellent natural models for...