chryseobacterium gregarium chryseobacterium gregarium chryseobacterium gregarium is a bacterium from the genus of chryseobacterium which has been isolated from plant material. chryseobacterium gregarium scientific classification domain: bacteria phylum: bacteroidota class: flavobacteriia order: flavobacteriales family: weeksellaceae genus: chryseobacterium species: c. gregarium binomial name chryseobacterium gregariumbehrendt et al. 2008 type strain cip 110171, dsm 19109, lmg 24052, p 461/12