Catalase & Coagulase Tests

What enzyme does the catalase test detect?

Catalase

what does catalase do?

Breaks hydrogen peroxide (H₂O₂) into water and oxygen.

What is the main purpose of the catalase test?

To differentiate Staphylococci (positive) from Streptococci (negative)

What reagent is used in the catalase test?

3% hydrogen peroxide 

What does a positive catalase test look like?

Rapid, sustained bubbling

what does a negative catalase test look like?

no bubbles w

which organism is catalase positive?

Staphylococcus aureus

which organism catalase negative? 

Streptococcus species 

Metabolically, what does a positive catalase test indicate?

The organism can detoxify hydrogen peroxide (aerobic/ faculatative metabolism)

Metabolically, what does a negative catalase test indicate?

The organism cannot break down hydrogen peroxide; lacks the catalase enzyme

what enzyme does the coagulase test detect? 

Coagulase 

What does coagulase do?

Converts fibrinogen to fibrin

why is coagulase important?

It helps bacteria form protective fibrin barriers—indicator of virulence.

what does a positive coagulase test look like? 

agglutination (visible clumping) 

what does a negative coagulase test look like?

No clumping

which bacterium is coagulase positive?

Staphylococcus aureus

which two groups are coagulase negative? 

Staphylococcus epidermidis and Streptococcus species.

what does a positive coalgulase test indicate metabolically/physiologically?

the organism produces coagulase, contributing to higher virulence

what does negative coagulase test indicate metabolically?

The organism does not produce coagulase and is typically less virulent

what test kit is commonly used for coagulase test =ing in this lab? 

BD BBL staphyloslide latex test