There are a lot of similarities between Enterobacter aerogenes and Klebsiella pneumonia. The urease test is one of the few tests that distinguishes E. aerogenes from K. pneumonia.   Enterobacter aerogenes is a Gram negative rod-shaped bacterium in the same family as Esherichia coli. It can grow on many of the same selective media as Esherichia coli, … including: MacConkey Agar, EMB agar and Lauryl-Tryptose broth.