Bile Solubility Test: Introduction, Principle, Test Requirements, Procedure, Result-Interpretation, and Keynotes

Bile Solubility Test- Positive and Negative

Introduction of Bile Solubility Test Bile solubility test uses for presumptive identification of Streptococcus pneumoniae. Principle of Bile Solubility Test Bile salts, specifically sodium deoxycholate and sodium taurocholate, have the capacity to selectively lyse Streptococcus pneumoniae when added to actively growing bacteria in agar or broth media. S. pneumoniae produces autolytic …

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Malonate Test: Introduction, Composition of Medium, Principle, Procedure, Uses, Result-Interpretation, and Limitations

Malonate Test Positive and Negative bacteria

Introduction of Malonate Test Malonate test uses to check the ability of the organism to utilize malonate as the sole source of carbon for energy. To differentiate bacteria on the basis of a malonate utilization test. It is a colorful test to check the ability of …

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Optochin Susceptibility Test: Introduction, Principle, Test Requirements, Procedure, Result-Interpretation, and Keynotes

Optochin Susceptibility Test-Positive

Optochin Susceptibility Test Optochin Susceptibility Test uses for presumptive identification of Streptococcus pneumoniae from viridans streptococci.  Principle of Optochin Susceptibility Test Ethylhydrocupreine hydrochloride (Optochin), a quinine derivative, selectively inhibits the growth of S. pneumoniae at a very low concentration (5ug/ml). Optochin may also inhibit other viridians streptococci, but only …

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CAMP Test: Introduction, Principle, Test Requirements, Procedure, Result-Interpretation,and Keynotes

CAMP Test-Positive

Introduction of CAMP Test  The CAMP test uses to identify preemptively Streptococcus agalactiae. It was first described in 1944 by Christie, Atkins, and Munch-Petersen, and the CAMP test is an acronym for their names. Principle of CAMP Test The beta lysin produced by Staphylococcus aureus is sphingomyelinase in nature, …

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Acetate Utilization Test: Introduction, Composition, Principle, Test Requirements, Test Procedure, Result and Interpretation, and Keynotes

Acetate Utilization Test-Negative (left) and Positive (right side)

Introduction of Acetate Utilization Test Acetate Utilization Test ueses to determine the ability of an organism to use acetate as the sole source of carbon same as in the citrate utilization test for Enterobacteriaceae. It is the recommended assay for the differentiation of Shigella species from Escherichia coli. Composition of …

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Corn Meal Agar (CMA): Introduction, Composition, Principle, Test Requirements, Test Procedure, Result-Interpretation, Colony Characteristics, Uses, and Keynotes

Colony Morphology of Aspergillus flavus on cornmeal agar (CMA) demonstration

Introduction of Corn Meal Agar (CMA) Corn Meal Agar (CMA) is a well-established fungal medium that is a suitable substrate for chlamydospore production by Candida albicans and the maintenance of fungal stock cultures. This is a very simple formulation containing only cornmeal infusion and agar. The addition of glucose …

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Nitrate or Nitrite Reduction Test: Introduction, Composition of Medium, Principle, Test Requirements, Procedure, Result -Interpretation, and Limitations

Nitrate or Nitrite Reduction Test

Introduction of Nitrate or Nitrite Reduction Test The nitrate or nitrite reduction test uses to determine the ability of an organism to reduce nitrate to nitrite. Anaerobic metabolism requires an electron acceptor other than atmospheric oxygen. Many gram-negative bacteria use nitrate as the final electron acceptor. The …

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DNase Test: Introduction, Composition, Principle, Test Requirements, Procedure, Result -Interpretations, and Limitations

Deoxyribonuclease (DNase) Test Positive and Negative Bacteria

Introduction of DNase Test for Bacteria DNase tests positive and negative bacteria as shown below image. This test is useful for the presumptive identification of Staphylococcus aureus which produces the enzyme deoxyribonuclease (DNase) from other Staphylococci which do not produce DNase. This test is also positive in the following …

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