[A study on the disc sensitivity test for cefsulodin]

Area of Science:

• Microbiology
• Antimicrobial Susceptibility Testing

Context:

• Accurate determination of bacterial susceptibility to antibiotics is crucial for effective treatment.
• Cefsulodin (CFS) is an antibiotic requiring reliable susceptibility testing methods.
• Traditional MIC methods can be time-consuming.

Purpose:

• To evaluate the correlation between the single-disc assay and the 2-fold agar dilution method for cefsulodin (CFS) susceptibility testing.
• To assess the applicability of the single-disc assay across different incubation times, including rapid assays.

Summary:

• 101 bacterial strains across 34 species were tested against cefsulodin (CFS) using both agar dilution and single-disc methods.
• Significant correlations were observed between MICs and inhibition zone diameters for conventional, delayed, and rapid (3-4 or 5-6 hours) single-disc assays.
• Regression equations were derived for each assay type, quantifying the relationship between zone diameter and MIC.

Impact:

• Validates the single-disc assay as a practical and reliable method for determining cefsulodin (CFS) susceptibility.
• Supports the use of rapid single-disc assays for faster clinical decision-making.
• Provides a basis for understanding potential experimental errors in MIC estimation using the disc diffusion method.