The class Bacteroidetes is composed of a single order of environmental bacteria. By far, the Bacteroidales class are the most well-studied of the Bacteroidetes. Some members of the genus Bacteroides are opportunistic pathogens.
- Bergey's Manual of Systematic Bacteriology, 2nd ed., vol. 1 (The Archaea and the deeply branching and phototrophic Bacteria) (D.R. Boone and R.W. Castenholz, eds.), Springer-Verlag, New York (2001). pp. 465-466.