Created by
Paul A. Gulig, Ph.D.
Department of Molecular Genetics and Microbiology
with assistance from
David Brumbaugh
What does this result mean?
B. The bacteria are citrate-negative.
Yes, the tube started off with the same green color, so no change occurred. This is in contrast to the tube on the bottom that was inoculated with a citrate-positive bacterium.
In our limited lab exercise this means that colony type 2 is normal E. coli. Note that there are many types of E. coli, some that cause different types of disease, and many that do not. You need to figure out if this E. coli could be involved in this patient's disease given the history and results of other bacterial tests.