A Note on Coagulase Test

Parker Nzeh^*
*Correspondence: Parker Nzeh, Department of Microbiology, Vrije Universiteit Brussel, Brussels, Belgium, Email:

Editorial

The fact that clots blood plasma makes coagulase a chemical. This test is performed on Gram-positive, catalase positive species to recognize the coagulase positive Staphylococcus aureus. Coagulase is a harmfulness component of S. aureus. The arrangement of cluster around a contamination brought about by this microbes probably shields it from phagocytosis. Coagulase responds with prothrombin in the blood. The subsequent complex is called staphylothrombin, which empowers the compound to go about as a protease to change over fibrinogen, a plasma protein created by the liver, to fibrin. This outcomes in thickening of the blood [1]. Coagulase is firmly bound to the outer layer of the bacterium S. aureus and can cover its surface with fibrin upon contact with blood. This test separates Staphylococcus aureus from other coagulase negative Staphylococcus species. The coagulase test has customarily been utilized to separate Staphylococcus aureus from coagulasenegative staphylococci. S.aureus produces two types of coagulase (i.e., bound coagulase and free coagulase). Bound coagulase, also called "amassing factor", can be identified via doing a slide coagulase test, and free coagulase can be distinguished utilizing a cylinder coagulase test [2].

A slide coagulase test is run with a negative control to preclude auto agglutination. Two drops of saline are put onto the slide marked with test number, Test (T) and control (C). The two saline drops are emulsified with the test organic entity utilizing a wire circle, straight wire, or wooden stick. A drop of plasma (hare plasma anticoagulated with EDTA is recommended) is put on the immunized saline drop comparing to test, and blended well, then, at that point, the slide is shaken delicately for around 10 seconds [3]. The cylinder test utilizes bunny plasma that has been vaccinated with a staphylococcal province (i.e., Gram-positive cocci which are catalase positive). The cylinder is then hatched at 37°C for 90 minutes. In the event that negative, hatching is gone on as long as 18 hours. The cylinder coagulase test is a substantial method for recognizing Staphylococcus aureus, gave that main a firm coagulation that doesn't move when the cylinder is tipped is viewed as a positive response. The generally proclaimed translation that all levels of thickening in coagulase plasma are a positive recognizable proof of S. aureus was refuted by the utilization of different tests, for example, anaerobic glucose aging thermonuclease creation, and lysostaphin awareness [4,5].

Uses of coagulase test

• The coagulase test is utilized to decide the creation of coagulase by various microorganisms.

• This test can likewise be utilized to separate S. aureus from other Staphylococcal species.

• Staphylococcal species are separated into coagulase-negative and coagulase-positive species based on the creation of the coagulase chemical.

Restrictions of coagulase test

• S. lugdunensis and S. schleiferi produce slide coagulase, yet the response is more proficient on the off chance that the human plasma is utilized as opposed to rabbiting plasma.

• Citrated blood ought not be utilized as bogus positive outcomes can happen.

• S. intermedius and S. hyicus might be positive in the cylinder test; these species are for the most part tracked down just in canines and pigs, separately, however are pretty much as irresistible as S. aureus when they taint people.

• Coagulase testing can't be performed from development on mannitol salt agar.

• Methicillin-safe S. aureus can be inadequate in bound coagulase, which brings about a negative slide test [6].

References

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2. Chapin, Kimberle, and Michael Musgnug. "Evaluation of three rapid methods for the direct identification of Staphylococcus aureus from positive blood cultures." J Clin Microbiol  9 (2003): 4324-4327.

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3. Gröbner, S., and V. A. J. Kempf. "Rapid detection of methicillin-resistant staphylococci by real-time PCR directly from positive blood culture bottles." Eur J Clin Microbiol Infect Dis 10 (2007): 751-754.

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4. Varettas, Kerry, Chinmoy Mukerjee, and Peter C. Taylor. "Anticoagulant carryover may influence clot formation in direct tube coagulase tests from blood cultures." J Clin Microbiol 9 (2005): 4613-4615.

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5. Aarestrup, Frank Møller, C. A. Dangler, and L. M. Sordillo. "Prevalence of coagulase gene polymorphism in Staphylococcus aureus isolates causing bovine mastitis." Canadian Journal of Veterinary Research 2 (1995): 124.

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6. Goh, Swee-Han, S. K. Byrne, J. L. Zhang, and A. W. Chow. "Molecular typing of Staphylococcus aureus on the basis of coagulase gene polymorphisms." J Clin Microbiol  7 (1992): 1642-1645.

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