[Drop method of determining micrococcal and staphylococcal sensitivity to egg lysozyme]

Area of Science:

• Microbiology
• Bacteriology
• Enzymology

Background:

• Lysozyme is a key enzyme in the innate immune system, targeting bacterial cell walls.
• Staphylococcal and micrococcal species are common bacteria with varying lysozyme susceptibility.
• Accurate determination of lysozyme Minimum Inhibitory Concentration (MIC) is crucial for understanding bacterial resistance.

Purpose of the Study:

• To compare the efficacy of a novel drop method with the established serial dilutions in agar method for assessing bacterial sensitivity to lysozyme.
• To validate the accuracy and reliability of the drop method for determining lysozyme MIC.
• To evaluate the simplicity and cost-effectiveness of the drop method.

Main Methods:

• Comparison of two methods: serial dilutions in agar and a modified drop method (based on Kloos et al.).
• Statistical analysis to determine the correlation between the results obtained from both methods.
• Development of a regression curve to correlate drop method results with lysozyme MIC.

Main Results:

• A strong positive correlation (r = 0.97 +/- 0.018) was observed between the drop method and the serial dilutions in agar method.
• The drop method was found to be simpler and more economical than the serial dilutions in agar method.
• The regression curve allows for accurate determination of lysozyme MIC using the drop method.

Conclusions:

• The developed drop method is a reliable and accurate alternative for determining staphylococcal and micrococcal sensitivity to lysozyme.
• The drop method offers significant advantages in terms of simplicity, cost-effectiveness, and suitability for testing single bacterial strains.
• This method can aid in research and diagnostics requiring assessment of lysozyme activity against Gram-positive cocci.