Gram-rods

Gram Negative Rods
This group contains the genera Shigella, Acinetobacter, Citrobacter, Enterobacter, Escherichia, Klebsiella, Morgonella, Proteus, Providencia, Salmonella, Seratia, Aeromonas, Alcaligenes,and Pseudomonas. The first stage in separating them is the catalase and oxidase tests.

Catalase Negative

Catalase Positive, Oxidase Negative

Catalase Positive, Oxidase Positive