ABSTRACT
The genus Aggregatibacter is classiŠed taxonomically in the family Pasteurellaceae, order Pasteurellales, class Gammaproteobacteria, phylum Proteobacteria. The family Pasteurellaceae currently includes 12 genera (Pasteurella, Actinobacillus, Haemophilus, Lonepinella, Mannheimia, Phocoenobacter, Gallibacterium, Histophilus, Volucribacter, Avibacterium, Nicoletella, Aggregatibacter) and 61 species. Members of the Pasteurellaceae family are characterized as gram-negative, nonmotile, aerobic, or facultatively anaerobic rods, coccoids, or Šlaments. Biochemically, due to their inability to synthesize nicotinamide adenine dinucleotide (NAD) de novo, they acquire this essential nutrient from their environment as either NAD or a limited number of precursors.1 Within the class Gammaproteobacteria, the nonmotility and the positivity for oxidase and phosphatase separate members of the Pasteurellaceae from those of the Enterobacteriaceae, which are motile and oxidase and phosphatase negative. Similarly, the lack of motility and lack of tolerance to high salt concentrations separate members of the Pasteurellaceae from most members of the Vibrionaceae.1
