What test will differentiate between Proteus vulgaris and Pseudomonas aeruginosa?

Answer 1

This is a bit tricky. Both Proteus vulgaris and Pseudomonas aeruginosa are Gram-negative and rod-shaped. According to Bergey's Manual of Systematic Bacteriology, Proteus vulgaris tests positive for sulfur reduction, urease production, tryptophan deaminase production, and indole production. Pseudomonas aeruginosa reduces sulfur and nitrate, and has a characteristic green color. The API 20E Identification System is a test strip that can be used to identify Proteus vulgaris versus other bacteria.

An even easier way to test this is the gelatinase test.

Or, slant the bacteria on a Triple Sugar Iron slant or place them in a SIM agar deep. P. vulgaris tests positive for Hydrogen Sulfide production, changing the media to a black color around the organism, while P. aeruginosa does not produce Hydrogen Sulfide.

Answer 2

Pseudomonas aeruginosa is a common bacterium that causes disease and infection in animals, including humans. It has a pearlescent appearance and grape-like or tortilla-like odor and thrives in moist surfaces.

Answer 3

1. gram stain---should be pink rods (gram negative)

2. lactose/glucose fermentation test (negative for both)

3. nitrate reduction test (positive)

4. litmus milk (peptonization should occur)

5. MR and VP (negative)

6. Citrate (positive)

Answer 4

Various tests can be preformed to test for the presence of Pseudomonas sp. in overnight culture media. These include VP, MR, TSI and Citrate utilization. Fermentation test needs to be performed as well. There are however API systems on the market that contains all the tests that you need to perform

Answer 5

P aeruginosa grows at 42 deg C while putida doesnt!

Answer 6

Cytochrome Oxidase test, Pseudomonas aeruginosa will be positive on oxydase strip (purple/blue).