A Gram negative bacteria, oxidase negative, showed the following results. The most suspected organism is:

Understand the Problem

The question is asking which organism is most likely suspected based on the given characteristics of a Gram negative, oxidase negative bacterium and the results shown in the image.

More Information

Enterobacter is part of the Enterobacteriaceae family and commonly found in a variety of environments. Its ability to utilize citrate and show a positive Voges-Proskauer test helps differentiate it from other similar bacteria like E. coli.

Tips

A common mistake is confusing Enterobacter with E. coli, which is also oxidase negative but typically methyl red positive and does not utilize citrate.

Sources

• Tests used to identify Gram Negative Bacteria - uwyo.edu
• Flow Chart of Gram Negative Organisms - medicine.osu.edu