Bacteria identification series
Gram positive bacteria identificstion chart
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Catalase test
Catalase Test- Principle, Procedure, Types, Results, Uses What is Catalase Test? The catalase test is a biochemical test for aerobic organisms that detects the production of catalase enzyme in the organism. Catalase enzyme is a common enzyme that is found in all living beings that survive in oxygen and catalyzes the decomposition of hydrogen peroxide, releasing water and oxygen. Catalase is an essential enzyme in pathogenic organisms as it protects the organism from oxidative damage from the reactive oxygen species. The enzyme neutralizes the bactericidal effects of hydrogen peroxide, and its concentration in bacteria has been correlated with the pathogenicity of the organism. The catalase test has been extensively used over the years as it allows the differentiation of catalase-positive organisms like staphylococci from catalase-negative species like streptococci. The catalase test is useful in the presumptive characterization of most bacteria. Under the aerobic condition, 3% H2O...
Coagulase test
Coagulase Test- Principle, Procedure, Types, Result, Uses Coagulase Test Definition A coagulase test is a biochemical test that is used to differentiate Staphylococcus aureus from other Staphylococci species like S. epidermidis and S. saprophyticus on the basis of the ability to produce the coagulase enzyme. The coagulase test is an important test that differentiates the species of the genus Staphylococci into two groups; Coagulase positive Staphylococci and Coagulase Negative Staphylococci. The coagulase enzyme acts as a virulence factor in some organisms as it interacts with the fibrinogen present on the host’s cell surface. Organisms with coagulase usually have a protective barrier around themselves, increasing their pathogenicity and resistance against the immune system. Coagulase is of two types; free coagulase and bound coagulase, each of which is detected by different methods. The bound coagulase is called the clumping factor and is detected rapidly by a slide test. The free c...