Microbiology Identification Tests

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What does a positive DNase test indicate?

Hydrolysis of the medium (correct)

Clear zone around the organism

Growth without fermentation

Presence of pink color

In the Mannitol Fermentation Test, what color indicates growth with fermentation?

Clear zone

Orange color

Yellow halos (correct)

Pink to red

What is the result of a Novobiocin Susceptibility Test for S.epidermidis?

Zone diameter less than or equal to 16 mm

Zone diameter greater than 16 mm (correct)

Yellow halos surrounding growth

No clearing observed

Which organism shows no color change or an orange color in the PYR Test?

S.aureus Signup and view all the answers

What does a negative catalase test result indicate?

Negative for catalase production Signup and view all the answers

What is the characteristic result of S.aureus in the Coagulase Test?

Positive coagulase activity Signup and view all the answers

What is the main purpose of the Catalase Test described in the text?

To test the breakdown of H2O2 into oxygen and water Signup and view all the answers

Which type of bacteria would most likely produce macroscopic clumping in the Coagulase Slide Test?

Staphylococcus aureus Signup and view all the answers

What is the result of the Coagulase Tube Test if no clot is formed?

Negative for free coagulase Signup and view all the answers

Which test detects the resistance to 0.04U Bacitracin?

Novobiocin Susceptibility Test Signup and view all the answers

What does a positive result in the DNAse Test suggest?

Presence of nuclease activity Signup and view all the answers

In the Mannitol Fermentation Test, what does a change in pH due to fermentation typically result in?

Yellow color change of the medium Signup and view all the answers

What is the purpose of using Colistin-Nalidixic Agar or Phenylethyl Alcohol Agar as mentioned in the text?

To selectively isolate Staphylococci Signup and view all the answers

Which organism shows total inhibition on Colistin-Nalidixic Agar or Phenylethyl Alcohol Agar?

E.coli Signup and view all the answers

What does a positive catalase test indicate?

Presence of Staphylococcus Signup and view all the answers

In the Novobiocin susceptibility test, which organism is resistant?

S.epidermidis Signup and view all the answers

What is the key characteristic of Mannitol Salt Agar?

Differential for Staphylococcus based on mannitol fermentation Signup and view all the answers

Which test can differentiate between Staphylococcus aureus and Staphylococcus epidermidis?

Coagulase test Signup and view all the answers