Biochemical Tests for Identification
of Enterobacteriaceaecontinued
Clinical Microbiology Review 180
TEST PRINCIPLE INTERPRETATION OTHER
Decarboxylase
reactions
Motility
Ornithine decarboxylase (ODC) differentiates
Klebsiella (neg) & Enterobacter (pos).
Most Enterobacteriaceae are pos, except
Klebsiella& Shigella. Differentiates Klebsiella
(neg) & Enterobacter (pos).
If organism has enzyme to
decarboxylate amino acid (e.g.,
ornithine, lysine, arginine), pH ↑,
pH indicator changes color.
Motile organisms grow away from
stab line in motility medium.
Pos = yellow to purple
Pos = movement away from
stab line or hazy appearance
throughout medium after
overnight incubation
