Klebsiella, on blood agar, often produces very large, glistening mucoid colonies because of its thick polysaccharide capsule. When touched with an inoculating loop, this colony may string out like thick, tenacious mucus.

Proteus is a highly motile organism that "swarms" across the surface of a blood agar plate in waves. Some Proteus species are very fast swimmers that can swarm across the entire plate, making it look like a brown film covering the agar.

The remaining enteric bacteria look similar to E. coli, pictured here, and thus must be differentiated by using biochemical tests. Hemolysis reactions vary from genus to species to strain among the enteric bacteria.