Laboratory Diagnosis of Staphylococci 2022

What temperature is the test tube incubated at for the coagulase testing of staphylococcus?

37°C

If no clotting is observed in the test tube after incubation at 37°C for an hour, what should be done next?

Examine at 30-minute intervals for up to 6 hours

Why should citrated blood not be used for the coagulase test?

It can lead to false-positive results

Can coagulase testing be performed using growth from mannitol salt agar?

No, it cannot be performed from growth on mannitol salt agar Signup and view all the answers

How is a DNase test spot inoculation performed?

Touch a colony of the organism with a loop and inoculate onto a small area Signup and view all the answers

What should be done after flooding a DNase test agar plate with 1N Hydrochloric Acid?

Decant excess hydrochloric acid Signup and view all the answers

What happens if Coagulase testing is performed with citrated blood?

It causes false-positive results Signup and view all the answers

Which agar type should not be used for Coagulase testing?

Mannitol Salt Agar Signup and view all the answers

What property of Staphylococcus aureus contributes to high infection rates and persistence despite treatment?

Producing biofilms Signup and view all the answers

Which of the following is a systemic illness associated with Staphylococcus aureus infections?

Toxic shock syndrome Signup and view all the answers

What plays a role in determining the treatment for Staphylococcus aureus infections?

Antibiotic resistance patterns and co-infection rates Signup and view all the answers

How does Staphylococcus aureus evade host immune responses?

By producing biofilms Signup and view all the answers

Which of the following is NOT a factor in the pathogenesis of Staphylococcus aureus infections?

Producing antibiotics Signup and view all the answers

What is the function of coagulase enzymes produced by Staphylococcus aureus?

Help the bacteria evade the human immune response Signup and view all the answers

Which toxin produced by Staphylococcus aureus disrupts the immune system by causing massive activation of host immune cells?

Toxic shock syndrome toxin-1 (TSST-1) Signup and view all the answers

In addition to causing skin and soft tissue infections, what else can Staphylococcus aureus infections lead to?

Systemic illnesses Signup and view all the answers

What role do exotoxins produced by Staphylococcus aureus play in causing diseases?

Activate host immune cells Signup and view all the answers

Where can Staphylococcus aureus be found besides infecting humans?

In soil, wildlife animals, and foodstuffs Signup and view all the answers