Microbial Diagnostic Disks: Introduction, List of Disks, Uses, and Related Footages

Optochin Susceptibility Test

Introduction of Microbial Diagnostic Disks Microbial Diagnostic Disks make it easy to presumptive identification of organisms. They are simple and easy to handle for the identification of bacteria in the Clinical Microbiology Laboratory. Some common examples of such disks are optochin, oxidase, and bacitracin. List …

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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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Gram Positive Cocci (GPC): Introduction, and List of Bacteria, Keynotes, and Related Images

Introduction of Gram Positive Cocci ‘Gram Positive Cocci (GPC)‘ bacteria retain crystal violet dye and stain blue or purple on Gram’s staining. The most common medically important bacteria of GPC are Staphylococcus aureus, Streptococcus pneumoniae, Enterococcus species, Streptococcus pyogenes, Streptococcus agalactiae and Staphylococcus saprophyticus. List …

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Pneumococcus and Viridans streptococci: Introduction, Differentiating Features, Keynotes, Pneumococcus, and Viridans streptococci Footages

Streptococcus pneumoniae Versus Viridans streptococci- Introduction, Differentiating Features, Keynotes, Pneumococcus, and Viridans streptococci Footages

Introduction of Streptococcus pneumoniae and Viridans streptococci Streptococcus pneumoniae is also called pneumococcus and pneumococcus is the commensals of the upper respiratory tract. It is an important etiological agent of pneumonia and otitis media in children that differs from streptococci in its morphology (diplococci), bile …

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Mueller-Hinton agar (MHA): Introduction, Composition, Principle, Preparation Requirements, Testing Procedure, Colony Characteristics, Uses, Keynotes, and MHA Footages

Mueller-Hinton agar (MHA): Introduction, Composition, Principle, Preparation Requirements, Testing Procedure, Colony Characteristics, Uses, Keynotes, and MHA Footages

History and Introduction of Mueller-Hinton Agar (MHA) The name Mueller- Hinton agar(MHA) is from the surname of co-developers microbiologist John Howard Mueller and veterinary scientist Jane Hilton at Harvard University as a culture for gonococcus and meningococcus, who published the method in 1941. It is a non-selective and non-differential …

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Coagulase Test: Introduction, Principle, Types, Test Requirements, Procedure, Result Interpretation, List of Coagulase Positive and Negative Bacteria, Limitations, and Keynotes

Coagulase Test: Introduction, Principle, Types, Test Requirements, Procedure, Result Interpretation, List of Coagulase Positive and Negative Bacteria, Limitations and Keynotes

Introduction of Coagulase Test The coagulase test is an enzymatic assay that is applied to differentiate Staphylococcus aureus (positive) from coagulase-negative staphylococci (CoNS). Coagulase is an enzyme formed by S. aureus which changes soluble fibrinogen of plasma to insoluble fibrin. S. aureus produces two forms of coagulase. One is bound coagulase …

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Catalase Test: Introduction, Principle, Procedure, Result Interpretation, and Precautions

Catalase Test- Introduction, Principle, Procedure, Result Interpretation and Precautions

Introduction of Catalase Test The catalase test is the most common in bacteriology and is commonly used to differentiate those bacteria that produce this enzyme, such as staphylococci, from non-catalase producing bacteria such as streptococci. It is two types depending on the testing methods and they …

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Staphylococcus and Micrococcus: Introduction, Differences, and Keynotes

Differences Between Staphylococcus and Micrococcus

Introduction of Staphylococcus and Micrococcus Staphylococci are Gram-positive bacteria, with diameters of 0.5 – 1.5 µm and non-motile, non-spore-forming facultative anaerobes that grow by aerobic respiration or by fermentation, and they are characterized by individual cocci, which divide in more than one plane to form …

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