Liofilchem® Ceftriaxone CRO, Antimicrobial Susceptibility Discs, 30 µg

Liofilchem® Ceftriaxone (CRO) Antimicrobial Susceptibility Discs, each containing 30 µg of ceftriaxone, are essential tools in clinical microbiology for determining bacterial susceptibility to ceftriaxone via the disk diffusion method. These discs aid in guiding effective antimicrobial therapy and monitoring resistance patterns.

Test Procedure:

1. Inoculum Preparation:
   • Select well-isolated colonies from an overnight culture.
   • Suspend the colonies in sterile saline or broth to achieve a turbidity equivalent to a 0.5 McFarland standard.
2. Inoculation of Agar Plate:
   • Dip a sterile swab into the prepared inoculum suspension.
   • Remove excess liquid by pressing the swab against the tube wall.
   • Evenly streak the swab over the entire surface of a Mueller-Hinton agar plate to ensure a uniform lawn of growth.
3. Application of Ceftriaxone Discs:
   • Allow the inoculated plate to dry for approximately 3–5 minutes at room temperature.
   • Using sterile forceps or a disc dispenser, place the ceftriaxone discs onto the agar surface, ensuring even spacing and firm contact with the agar.
4. Incubation:
   • Incubate the plate in an inverted position at 35 ± 2°C for 16–18 hours under ambient atmospheric conditions.
5. Reading and Interpretation:
   • After incubation, measure the diameter of the inhibition zones around each disc to the nearest millimeter.
   • Interpret the results using the latest Clinical and Laboratory Standards Institute (CLSI) or European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines.

Quality Control:

To ensure the accuracy and reliability of the test, perform quality control using standard reference strains with known susceptibility profiles. For ceftriaxone discs, the following quality control strains and their expected zone diameter ranges are recommended:

Regular testing of these control strains ensures that the test conditions are optimal and that the ceftriaxone discs are performing within specified parameters. If the zone diameters obtained for the control strains fall outside the expected ranges, investigate potential issues with the testing procedure, reagents, or equipment.

Clinical Significance:

Ceftriaxone is a third-generation cephalosporin with broad-spectrum activity against Gram-positive and Gram-negative bacteria. It is commonly used to treat infections such as pneumonia, meningitis, and sepsis. Determining bacterial susceptibility to ceftriaxone is crucial for effective treatment planning and combating antimicrobial resistance.

Regulatory Data:

Liofilchem® Ceftriaxone discs comply with international standards for antimicrobial susceptibility testing. They are manufactured under strict quality control measures to ensure consistent performance. For detailed regulatory information, refer to the manufacturer's documentation.

Comparison with Other Brands:

Several manufacturers offer ceftriaxone susceptibility discs. Below is a comparative overview:

Advantages of Liofilchem® Ceftriaxone Discs:

• Compliance with Multiple Standards: Adherence to both CLSI and EUCAST guidelines ensures broad applicability.
• Flexible Packaging: Available in various pack sizes to accommodate different laboratory needs.
• Consistent Performance: Manufactured under stringent quality control for reliable results.

References:

• Liofilchem® Antibiotic Disc Instructions for Use: Liofilchem
• CLSI Performance Standards for Antimicrobial Susceptibility Testing
• EUCAST Clinical Breakpoints

For detailed procedures, quality control ranges, and interpretative criteria, always refer to the manufacturer's instructions and the latest CLSI and EUCAST guidelines.