Liofilchem® Brilliant Green Agar with Sulfapyridine, 500g

Liofilchem® Brilliant Green Agar with Sulfapyridine is a highly selective culture medium formulated for the isolation of Salmonella species (excluding S. Typhi and S. Paratyphi) from food, animal feed, and environmental samples.

This formulation enhances the classical Brilliant Green Agar by incorporating sodium sulfapyridine, which provides additional selectivity against competing Gram-positive and Gram-negative bacteria, while allowing robust recovery of Salmonella spp. The inclusion of phenol red as a pH indicator enables visual differentiation based on carbohydrate fermentation reactions.

Key Features

• Highly selective medium for Salmonella detection and enumeration.
• Enhanced inhibition of non-target microorganisms through brilliant green and sulfapyridine.
• Differential identification via color change using phenol red indicator.
• Supports regulatory food and water testing standards (AOAC, APHA, ISO).
• Validated against Salmonella Typhimurium ATCC® 14028 for optimal recovery and colony morphology.
• Complies with international testing guidelines for Salmonella in foods, dairy, and environmental samples.

Principle of the Medium

• Enzymatic digests of animal tissue and casein provide amino acids, peptides, and nitrogen for microbial growth.
• Yeast extract supplies essential B vitamins and growth factors.
• Lactose and sucrose serve as fermentable carbohydrates for differential colony response.
• Brilliant green dye and sulfapyridine act as selective agents, inhibiting Gram-positive bacteria and most Gram-negative organisms except Salmonella spp.
• Phenol red functions as a pH indicator to visualize carbohydrate fermentation.
• Agar solidifies the medium, allowing distinct colony morphology.

Typical Formula (per litre)

Preparation

1. Suspend 59 g of the medium in 1 L of distilled or deionized water.
2. Heat with constant stirring until completely dissolved.
3. Autoclave at 121°C for 15 minutes.
4. Cool to 45–50°C, mix well, and pour into sterile Petri dishes.
5. Avoid overheating or prolonged sterilization to maintain selectivity.

Test Procedure

1. Inoculate the plates either:
   • Directly from the sample, or
   • From a selective enrichment broth (e.g., Tetrathionate Broth, Selenite Cystine Broth).
2. Incubate aerobically at 35 ± 2°C for 18–24 hours.
3. If no growth is observed, continue incubation up to 48 hours.
4. Examine for typical Salmonella colonies.

For best recovery of all enteric pathogens, use Brilliant Green Agar in combination with a less selective medium such as MacConkey Agar or Hektoen Enteric Agar.

Interpretation of Results

Confirm presumptive Salmonella colonies using biochemical or serological identification tests.

Quality Control

Appearance (Dehydrated): free-flowing, homogeneous beige to pink powder

Appearance (Prepared): slightly opalescent, orange-brown to dark amber

Storage and Stability

• Store dehydrated medium at 10–30°C, tightly closed, in a dry environment.
• Store prepared plates at 2–8°C, protected from light.
• Do not use beyond the expiry date or if contamination or caking occurs.
• Shelf Life: 4 years (dehydrated medium).

Safety and Handling

• Contains Brilliant Green and Sodium Sulfapyridine — classified as hazardous substances.
• Use only by trained laboratory personnel under appropriate safety conditions.
• Refer to the Safety Data Sheet (SDS) before use.
• Dispose of all media and cultures according to local biohazard regulations.

Ordering Information

Liofilchem® Brilliant Green Agar with Sulfapyridine provides a robust and selective formulation for the isolation and differentiation of Salmonella spp. from complex food and environmental samples. By combining brilliant green dye and sulfapyridine as dual selective agents, it achieves strong inhibition of non-target flora while maintaining high recovery rates of Salmonella. This medium is a dependable choice for food safety laboratories, environmental microbiology, and industrial quality control testing where precision and reproducibility are critical.