This video lesson demonstrates how to interpret the results of the coagulase test used in identifying staphylococcus aureus. Catalase test catalase test catalase is the enzyme that breaks hydrogen peroxide h 2o2 into h 2o and o 2. In biochemistry, tests tags catalase test, catalase test precautions, catalase test priniciple, catalase test procedure, results july 22, 2016 2587 views hamza khan. H 2o2 is a potent oxidizing agent that can wreak havoc in. How soon will agglutination appear on the coagulase slide test if it is a positive result. It is an important indicator for the pathogenicity of staphylococcus strains. The coagulase test can be performed using two different procedures slide test and tube test.
It is a waste to run the test on a nonstaph isolate. Catalase serves to neutralize the bactericidal effects of hydrogen peroxide. Catalase is an enzyme present in most cytochrome containing aerobic and facultative anaerobic bacteria. Slide test to detect bound coagulase place a drop of physiological saline on each end of a slide, or on two separate slides. The coagulase test for staphylococci sciencedirect. In addition, the microtube method offers a more convenient and economical format for the performance of the coagulase tube test. Dnase test agar is not intended for use in the diagnosis of disease or other conditions in humans. Be sure that you have a staph before running this test. With the loop, straight wire or wodden stick, emulsify a portion of the isolated colony in each drops to make two thick suspensions. This test demonstrate the presence of catalase, an enzyme that catalyses. The coagulase test is used to differentiate species of staphylococcus, especially the coagulase positive staphylococcus aureus from coagulase negative staphylococcal species. It is concluded that in most instances, the latex slide agglutination test is areliable methodfor identifying s. Catalase is the enzyme that catalyzes to split up hydrogen peroxide into its reactant water and oxygen. To introduce and demonstrate the principle and experimental set up for determining the microbes ability to detoxify hydrogen peroxide and or to cause blood coagulation.
Pdf tube coagulase testing for the identification of. Slide coagulase test may be used to screen isolates of s. Indeed, according to the manufacturers instructions, s intermedius strains would be identified as coagulase negative. On isolates from critical specimens, a negative coagulase test obtained with an inoculum of less than two colonies should be confirmed by repeating the procedure with a larger inoculum or by using. If so what is the best and most cost effective procedure to perform the tube coagulase test. Choose from 200 different sets of coagulase test flashcards on quizlet. Full text get a printable copy pdf file of the complete article 663k, or click on a page image below to browse page by page.
Uk standards for microbiology investigations smis are developed under the auspices of public health england phe working in partnership with the national health service nhs, public health wales and with the professional organisations. If possible, perform the test under a biosafety hood. Place a drop of coagulase plasma preferably rabbit plasma with ethylenediaminetetraacetic acid edta on. The tube test is the definitive test, however, it can take up to 24 hours to complete.
The slide test is performed by preparing a suspension of bacterial cells mixed into a drop of rabbit plasma on a microscope slide. The slide test is simple, giving results within 10 seconds, but it can give false negatives. Laboratory procedure bbl staphyloslide latex test for staphylococcus aureus i. The widely promulgated interpretation that all degrees of clotting in coagulase plasma are a positive identification of s. While there are seven antigenic types of free coagulase, only one antigenic type of bound coagulase exists. The tube coagulase test is thought to be the more definitive of the two, however, it can take several hours to overnight to produce a result. Coagulase production is confined to pathogenic strains of staphylococci and this test is specific for the identification of these strains. Why should the test tube coagulase test be incubated for no more than 24 hours. The bound coagulase is also known as clumping factor. Rapidly identify and differentiate staphylococci which possess coagulase andor protein a, particularly staphylococcus aureus, using the thermo scientific staphaurex latex agglutination test. Learn coagulase test with free interactive flashcards. Bound coagulase is detected by the slide coagulase test, whereas free coagulase is detected by the tube coagulase test. Free coagulase reacts with a substance in plasma to form a fibrin clot.
The tube coagulase test detects both bound and free coagulase. Coagulaseproduction staphylococcus differing traditional. Coagulase slide tests have been carried out on food, human and animal strains of staphylococci with human and animal plasmas. This video was prepared by the teaching support team for the university of western australias school of pathology and laboratory medicine palm.
The coagulase test is used to differentiate species of staphylococcus, especially the coagulasepositive staphylococcus aureus from coagulasenegative staphylococcal species. Coagulase test principle, procedure and result interpretation. The test is used to differentiate staphylococcus aureus positive from coagulasenegative staphylococci negative. This enzymatic test is essential in the scheme of identification for grampositive organisms and certain gramnegative organisms. Free coagulase is detected in tube coagulase test and bound coagulase is detected in slide coagulase test.
Coagulase test slide for microbiology slide coagulase. Bound coagulase, otherwise known as clumping factor, can be detected by carrying out a slide coagulase test, and free coagulase can be detected using a tube coagulase test. This version of the coagulase test is used to identify the presence of either bound coagulase or free coagulase, which is an extracellular enzyme. Using a sterile loop emulsify 24 colonies of the test organism into the plasma. Place a drop of distilled water or saline next to the drop of plasma as a control. Both common versions of the test, the slide method and the test tube method, are described, and the mechanisms of the reactions are discussed.
This protocol describes the history and procedures of the coagulase test. Coagulase test the enzyme coagulase, produced by a few of the staphylococcus species, is a key. Coagulase test is used to differentiate staphylococcus aureus positive from coagulase negative staphylococcus cons. The tube coagulase test is a valid means of identifying staphylococcus aureus, provided that only a firm clot that does not move when the tube is tipped is considered a positive reaction. The coagulase test has traditionally been used to differentiate staphylococcus aureus from coagulasenegative staphylococci. The catalase test is used primarily in differentiation between certain genera and species of bacteria. Emulsify several isolated colonies of test organism in 1 ml of diluted rabbit plasma to give a milky suspension. The catalase test is used to detect the presence of the enzyme catalase in bacteria. Field and smith 8 compared the plasmas of several animal species for use in the slide test.
The coagulase tube test has been set up as a demo for you to observe in class. Coagulase test is carried out to differentiate potentially pathogenic staphylococcus species from other gram positive, catalasepositive cocci by the detection of coagulase. Discussion when s aureus is suspected most hospital microbiologists usually perform a simple confirmatory test at the bench. Staphaurex is a rapid slide agglutination procedure for differentiating staphylococci which possess coagulase andor protein a, particularly staphylococcus aureus, from staphylococci which possess neither of these factors. Other staphylococci do not produce coagulase, thus this test can distinguish s. Catalase test principle, uses, procedure, result interpretation with precautions. Product summary and explanation in 1956, weckman and catlin showed a correlation between increased dnase activity of staphylococcus aureus and positive coagulase activity. Slide coagulase test 1 remove a single tube of coagulase cryo from the freezer and permit it to thaw to room temperature. In addition to potential selfcontamination by aerosol exposure, mycobacteria speciation by the catalase test is achieved by different techniques not discussed in this protoc ol 3, 5, 7.
The slide coagulase test may yield a negative result for. I watched many variants of the procedure on youtube. Therefpre, tube coagulase test still remain a test of choice for s. Coagulase test virtual interactive bacteriology laboratory. Hydrogen peroxide is often used as a topical disinfectant in wounds, and the bubbling that is seen is due to the evolution of o 2 gas. Bound coagulase adsorbs fibrinogen from the plasma and alters it so it precipitates on the staphylococci, causing them to clump resulting in cell agglutination. Do not use this procedure for mycobacteria testing. Microtube coagulase test for detection of coagulase.
Using a sterile 1 ml serological pipette, add approximately 0. Its concentration in bacteria has been correlated with pathogenicity. Your instructor will direct you as to which procedure to use, but the tube test is the definitive test. Numerous plating media have been preparedwithhumanorrabbit plasmas 6, 7, 10, 15, 17. Please update to the latest version of flash player. Provide alternate content for browsers that do not support scripting or for those that have scripting disabled.
735 1418 567 838 1314 1430 116 274 1377 622 1485 637 932 1541 676 704 1567 33 194 22 82 539 547 96 463 466 732 52 33 1196 1042 1127 438 1131 1304 277 379 1440