Is Micrococcus luteus affected by lysozyme?
Is Micrococcus luteus affected by lysozyme?
Introduction. In the 1920s, Alexander Fleming described lysozyme as a bactericidal factor of human and other animal tissues and secretions. 1 He also discovered and named a yellow bacterium, Micrococcus lysodeikticus (now M luteus), that was highly susceptible to lysozyme-mediated killing.
How is lysozyme activity measured?
Lysozyme activity is measured at OD 450 by tracking the decrease in optical density as the substrate’s cell wall is broken by the enzyme if it is present. Today you will determine the ideal concentration of a stock lysozyme solution to use as a positive standard in this assay in the future.
What is Micrococcus luteus resistant to?
Abstract. A plasmid designated pMEC2 which confers resistance to erythromycin, other macrolides, and lincomycin was detected in Micrococcus luteus strain MAW843 isolated from human skin. Curing of this approximately 4.2 kb plasmid from the host organism resulted in erythromycin sensitivity of the strain.
How do you identify Micrococcus luteus?
It can commonly be mis-identified by eye as Staphylococcus aureus due to the golden / yellow colour so identification beyond colony morphology is required. Other distinguishing identification features are that M. luteus is urease & catalase but coagulase negative.
What is lysozyme assay?
Lysozyme Activity Assay Kit (ab211113) provides a convenient method for quantifying Lysozyme activity in mammalian cell or tissue lysates, biological fluids such as tears or saliva. This product can also be used to measure lysozyme activity in yeast and bacteria.
How do you calculate lysozyme concentration?
Calculate the absorbance difference ΔA (2 min) = A1 – A2. As further on described, draw a calibration curve using LYSOZYME STANDARD (REF 7200) kit. Calculate the concentration in the samples by the calibration curve. Dilute 0.4 ml of LYSOZYME STANDARD 500 mg/L with to 3.6 ml of saline solution.
How can you identify Micrococcus luteus?
How can you distinguish between Micrococcus luteus and Staphylococcus epidermidis?
MANNITOL SALT AGAR
| TEST | Staphylococcus aureus | Staphylococcus epidermidis |
|---|---|---|
| Catalase | Positive | Positive |
| Glucose Fermentation | Positive | Positive |
| Coagulase | Positive | Negative |
| Salt Tolerance on Mannitol Salt Tolerance | Positive | Positive |
What type of hemolysis is Micrococcus?
gamma
| Genus species Gram+ | Morphology* | Hemolysis* |
|---|---|---|
| Micrococcus luteus | G+ cocci/packets | gamma |
| Mycobacterium smegmatis | G+ rod | ND |
| Staphylococcus aureus | G+ cocci/clusters | beta |
| Staphylococcus epidermidis | G + cocci | gamma |
