Salmonella & Shigella Biochemical Tests: Differentiation & Results

Biochemical tests for Salmonella and Shigella

Biochemical tests are used to differentiate Salmonella and Shigella species. The following are some of the commonly used biochemical tests:

1. Urease test:

- Salmonella: Negative

- Shigella: Positive

2. Indole test:

- Salmonella: Negative

- Shigella: Negative

3. Methyl red test:

- Salmonella: Positive

- Shigella: Negative

4. Voges-Proskauer test:

- Salmonella: Negative

- Shigella: Negative

5. Citrate utilization test:

- Salmonella: Positive

- Shigella: Negative

6. Lysine decarboxylase test:

- Salmonella: Positive

- Shigella: Negative

7. Ornithine decarboxylase test:

- Salmonella: Positive

- Shigella: Negative

8. H2S production:

- Salmonella: Negative

- Shigella: Positive

These biochemical tests can help to differentiate Salmonella and Shigella species, but it is important to note that some strains may show atypical reactions. Therefore, it is always important to use multiple tests in order to accurately identify a bacterial species.