Prevotella

**Definition:** A genus of gram-negative, anaerobic, nonsporeforming, nonmotile rods. Organisms of this genus had originally been classified as members of the BACTEROIDES genus but overwhelming biochemical and chemical findings in 1990 indicated the need to separate them from other Bacteroides species, and hence, this new genus was established.

**Tree numbers:** - B03.440.080.094.640 - B03.440.425.410.194.640