avibacterium avibacterium avibacterium is a genus of gram-negative bacteria from the family pasteurellaceae. avibacterium scientific classification domain: bacteria phylum: pseudomonadota class: gammaproteobacteria order: pasteurellales family: pasteurellaceae genus: avibacteriumblackall et al. 2005 type species avibacterium gallinarum species a. avium a. endocarditidis a. gallinarum a. paragallinarum a. volantium