Staph Aureus Biochemical Tests: What You Need To Know

Biochemical tests for Staphylococcus aureus

Staphylococcus aureus or staph aureus is a type of bacteria that can cause a wide range of infections, from minor skin infections to more serious conditions such as pneumonia, endocarditis, and sepsis. Identifying staph aureus is crucial in treating infections caused by this bacterium. One of the ways to identify staph aureus is through biochemical tests.

What are Biochemical Tests?

Biochemical tests are laboratory tests that help identify bacteria based on their metabolic processes. These tests use different reagents to determine the presence or absence of specific enzymes that are unique to certain bacteria. Biochemical tests are commonly used in clinical microbiology to identify and treat bacterial infections.

Common Biochemical Tests for Staph Aureus

There are several biochemical tests that can be used to identify staph aureus. Some of the most common tests include:

Coagulase Test:

The coagulase test is used to determine whether a bacteria produces coagulase, an enzyme that clots blood. Staph aureus is coagulase-positive, which means it produces coagulase, while other staphylococci are coagulase-negative.

Catalase Test:

The catalase test is used to determine whether a bacteria produces catalase, an enzyme that breaks down hydrogen peroxide into water and oxygen. Staph aureus is catalase-positive, which means it produces catalase, while streptococci are catalase-negative.

Mannitol Salt Agar Test:

The Mannitol Salt Agar test is used to determine whether a bacteria can ferment mannitol, a type of sugar. Staph aureus ferments mannitol, which causes the medium to turn yellow.

Why are Biochemical Tests Important?

Biochemical tests are important in identifying bacteria because they help determine the appropriate treatment for bacterial infections. Different bacteria require different treatments, and using the wrong antibiotic can lead to antibiotic resistance, which makes it harder to treat bacterial infections.


Biochemical tests are essential in identifying staph aureus, which is a common cause of bacterial infections. The coagulase test, catalase test, and Mannitol Salt Agar test are some of the most common tests used to identify staph aureus. Identifying the correct bacteria is crucial in treating bacterial infections, and biochemical tests play a vital role in achieving this goal.

Remember, if you suspect you have a bacterial infection, it’s important to seek medical attention from a qualified healthcare provider. They can perform the necessary tests to identify the bacteria and prescribe the appropriate treatment.