fretibacterium fretibacterium fretibacterium is a genus of bacteria from the family of synergistaceae with one known species (fretibacterium fastidiosum). fretibacterium fastidiosum has been isolated from subgingival plaque. fretibacterium scientific classification domain: bacteria phylum: synergistota class: synergistia order: synergistales family: synergistaceae genus: fretibacteriumvartoukian et al. 2013 type species fretibacterium fastidiosum species fretibacterium fastidiosum