What is the purpose of a coagulase test?

What is the purpose of a coagulase test?

The coagulase test identifies whether an organism produces the exoenzyme coagulase, which causes the fibrin of blood plasma to clot.

What is the mechanism of action of coagulase enzyme?

Coagulase reacts with prothrombin in the blood. The resulting complex is called staphylothrombin, which enables the enzyme to act as a protease to convert fibrinogen, a plasma protein produced by the liver, to fibrin. This results in clotting of the blood. Coagulase is tightly bound to the surface of the bacterium S.

What is the purpose of the coagulase test quizlet?

What is the purpose of the coagulase test? To determine the presence or absence of the coagulase protein.

What is the reagent in the coagulase test?

The Tube Coagulase Test consists of putting approximately 1 ml of coagulase reagent (rabbit plasma) in a labeled test tube and incubating it at 34 to 37 degrees Celsius from 4 to 24 hours. If the tube has a thick, solid clot within 24 hours, it is Staphylococcus aureus.

Why is rabbit plasma used in coagulase test?

The formation of a clot in the plasma indicates coagulase production. The tube test is the most frequently used method because of its greater accuracy and its ability to detect both bound and free coagulase. Coagulase Plasma is lyophilised rabbit plasma to which EDTA has been added as the anticoagulant.

Is coagulase an exo or Endoenzyme?

Is coagulase an endoenzyme or an exoenzyme? Explain. Coagulase is an exoenzyme because it is secreted outside of the cell in order to convert fibrinogen in the serum to fibrin which will help to form clot.

Why rabbit plasma is used in coagulase test?

Which form of the coagulase test will detect the presence of either form of coagulase?

Coagulase production can be detected using either the slide coagulase test (SCT) or the tube coagulase test (TCT). Slide coagulase detects bound coagulase (also called “clumping factor”) [9], which reacts directly with fibrinogen in plasma, causing rapid cell agglutination.

How do you perform a coagulase slide test?

Slide Test (to detect bound coagulase) Add a drop of human or rabbit plasma to one of the suspensions, and mix gently. Look for clumping of the organisms within 10 seconds. No plasma is added to the second suspension to differentiate any granular appearance of the organism from true coagulase clumping.

How does the production of coagulase help bacteria quizlet?

Terms in this set (19) The fibrin clot may protect the bacterium from phagocytosis and isolate it from other defenses of the host. coagulase will react with prothrombin in rabbit plasma to catalyze the precipitation of fibrin from fibrinogen. As fibrin is formed it causes cells to clump together.

Is human plasma used in coagulase test?

Coagulase testing is the most widely used in vitro test to determine the potential pathogenicity of staphylococci. We demonstrated that human plasma gives results comparable to those obtained with commercial rabbit plasma; however, positive and negative controls must be included in all coagulase procedures.

What makes coagulase important for a pathogen?

The action of the coagulase provides an important protective barrier from the immune system, but when nutrient supplies are diminished or other conditions signal a need for the pathogen to escape and spread, the production of staphylokinase can initiate this process.

What is the reagent used in a coagulase test?

The Coagulase Test is used to differentiate Staphylococcus aureus from other species of this genus. To perform the Slide Coagulase Test, place a drop of coagulase reagent (rabbit plasma) onto a clean microscope slide, and then add several colonies of the unknown Staphylococcus.

What does coagulase negative staphylococcus mean?

Coagulase-negative staphylococci (CoNS) are a type of staph bacteria that commonly live on a person’s skin. Doctors typically consider CoNS bacteria harmless when it remains outside the body. However, the bacteria can cause infections when present in large amounts, or when present in the bloodstream.