Liofilchem® Chromatic™ ESBL Agar Base

Liofilchem® Chromatic™ ESBL Agar Base is a chromogenic and selective agar medium formulated for the detection, isolation, and differentiation of Extended-Spectrum β-Lactamase (ESBL) and AmpC-producing Enterobacteriaceae directly from clinical samples.

Used in combination with either Chromatic™ ESBL Supplement (Ref. 81089) or Chromatic™ ESBL + AmpC Supplement (Ref. 81090), the complete system provides rapid visual differentiation of resistant Gram-negative organisms such as Escherichia coli, Klebsiella pneumoniae, Enterobacter spp., and Serratia spp.

This chromogenic approach supports rapid resistance screening in accordance with EUCAST guidelines, making it a powerful tool for clinical microbiology, hospital infection control, and antimicrobial resistance (AMR) surveillance programs.

Key Features

• Chromogenic selective agar for detection of ESBL and AmpC β-lactamase producers.
• Used with Chromatic™ ESBL Supplement (81089) or Chromatic™ ESBL + AmpC Supplement (81090).
• Differentiates Enterobacteriaceae species based on colony color.
• E. coli: Pink-reddish-mauve; Klebsiella/Enterobacter/Serratia: Green-blue; Proteus: Brown.
• Accurate detection of ESBL and AmpC enzymes within 18–24 hours.
• EUCAST and CLSI guideline compliant for β-lactamase detection.
• Available in dehydrated powder format for flexibility and long shelf life.
• Ideal for clinical, hospital, and reference laboratories conducting ESBL/AmpC screening.

Typical Formula (per litre)

Principle of the Method

• Peptone mix provides essential nitrogen, amino acids, and vitamins to support bacterial growth.
• Chromogenic substrates enable identification of resistant organisms by enzyme-specific color reactions.
• Agar acts as the solidifying matrix for colony differentiation.
• When used with Chromatic™ ESBL Supplement, only ESBL-positive strains grow, while Chromatic™ ESBL + AmpC Supplement permits detection of both ESBL and AmpC producers.

The supplement choice determines selectivity level:

• Chromatic™ ESBL Supplement → higher selectivity (ESBL only).
• Chromatic™ ESBL + AmpC Supplement → dual detection (ESBL + AmpC).

Preparation

1. Suspend 59.2 g of powder in 1 L of deionized or distilled water.
2. Heat and mix until fully dissolved.
3. Autoclave at 121°C for 15 minutes.
4. Cool to 45–50°C.
5. Aseptically add 2 vials (10 mL total) of either Chromatic™ ESBL Supplement (81089) or Chromatic™ ESBL + AmpC Supplement (81090).
6. Mix gently and pour into sterile Petri dishes.

Technique

1. Inoculate directly from clinical specimens using sterile loop or swab.
2. Incubate aerobically at 37°C for 18–24 hours.
3. Observe colony morphology and color for interpretation.

Interpretation of Results

Quality Control

Incubation: 18–24 h at 35 ± 2°C (aerobic).

Dehydrated Medium: beige, free-flowing, homogeneous.

Prepared Medium: slightly opalescent, amber.

Storage and Stability

• Store dehydrated powder at 10–30°C, tightly sealed and dry.
• Store prepared plates at 2–8°C, protected from light.
• Shelf life: 2 years (dehydrated medium).
• Discard if contamination or deterioration occurs.

Safety and Handling

• For in vitro diagnostic use only.
• Use by trained laboratory professionals under biosafety level 2 (BSL-2) precautions.
• Consult Safety Data Sheet (SDS) before use.
• Dispose of used plates and cultures according to local and national biosafety regulations.

Ordering Information

Liofilchem® Chromatic™ ESBL Agar Base, combined with either ESBL or ESBL + AmpC Supplements, offers a rapid, reliable, and chromogenic method for the detection of ESBL and AmpC β-lactamase-producing Enterobacteriaceae. With clear color differentiation and high selectivity, it is an essential diagnostic medium for clinical microbiology laboratories, infection control programs, and antimicrobial resistance surveillance.