Liofilchem ESBL disc kit (acc. to EUCAST) 50 tests

The Liofilchem® ESBL Disc Kit is designed for the phenotypic confirmation of Extended-Spectrum β-Lactamase (ESBL)-producing Enterobacteriaceae, in accordance with EUCAST standards. Below are the details of the kit's components and references.

Kit Components

1. Disc Types:
   • Cefotaxime (CTX) 30 µg: Indicator cephalosporin.
   • Cefotaxime + Clavulanic Acid (CTL) 40 µg (30 + 10 µg): For detecting synergy with clavulanic acid.
   • Ceftazidime (CAZ) 30 µg: Indicator cephalosporin.
   • Ceftazidime + Clavulanic Acid (CAL) 40 µg (30 + 10 µg): Detecting synergy.
   • Cefepime (FEP) 30 µg: For organisms with suspected AmpC activity.
   • Cefepime + Clavulanic Acid (FEL) 40 µg (30 + 10 µg): Detects synergy in AmpC producers.
2. Packaging:
   • Cartridges with 6 x 50 discs each, packaged in blisters with a desiccant to ensure stability.
3. Storage Instructions:
   • Store at -20°C to +8°C.
   • Open cartridges at room temperature to avoid condensation.
   • Unused discs should be returned to 2-8°C and used within 7 days.

Testing Principle

• Combination Disc Test (CDT):
  • Tests the inhibitory synergy of clavulanic acid with cefotaxime, ceftazidime, or cefepime.
  • A positive result is indicated by an ≥ 5 mm increase in inhibition zone diameter for the cephalosporin when combined with clavulanic acid.

Quality Control

• Positive Controls:
  • Klebsiella pneumoniae ATCC® 700603 (SHV-18 ESBL producer).
  • Escherichia coli NCTC 13353 (CTX-M-15 ESBL producer).
• Negative Control:
  • Escherichia coli ATCC® 25922.

References

1. EUCAST Technical Guidance (2019): "New disk potencies for combination disks containing cefotaxime and ceftazidime with and without clavulanic acid."
2. EUCAST Guidelines (Version 2.0, 2017): "Detection of resistance mechanisms and specific resistances of clinical and/or epidemiological importance."