Thermo Scientific™ Oxoid™ Bacillus cereus Selective Agar Base (Dehydrated)

The Thermo Scientific™ Oxoid™ Bacillus Cereus Selective Agar Base (Dehydrated) is a highly selective and diagnostic medium designed to isolate and enumerate Bacillus cereus from food, environmental, and clinical samples. The medium is based on the selective and diagnostic PEMBA (Polymyxin Pyruvate Egg Yolk Mannitol Bromothymol Blue Agar) medium, ensuring the detection of Bacillus cereus even in the presence of large numbers of contaminants. The unique formulation differentiates Bacillus cereus from other species of Bacillus and inhibits Gram-negative bacteria.

Key Features

1. Selective and Diagnostic:
   • Incorporates Polymyxin B supplement to inhibit Gram-negative organisms such as Escherichia coli and Pseudomonas aeruginosa.
   • Differentiates Bacillus cereus from other Bacillus species based on resistance to polymyxin, mannitol fermentation, and lecithinase activity.
2. Reliable Identification:
   • Typical colonies of Bacillus cereus are turquoise to peacock blue with a crenated appearance (5 mm diameter) and surrounded by a precipitate of hydrolyzed lecithin.
   • Distinguishes Bacillus cereus from other species, including Bacillus thuringiensis.
3. High Sensitivity:
   • Capable of detecting small numbers of Bacillus cereus cells and spores in the presence of large numbers of food contaminants.
4. Versatile Applications:
   • Suitable for isolating Bacillus cereus from food samples, fecal samples, and clinical specimens.
5. High Yield:
   • One 500 g package yields up to 12.2L of prepared medium, making it cost-effective for large-scale testing.

Applications

1. Food Microbiology

• Detection and enumeration of Bacillus cereus in contaminated food products, particularly rice, dairy, meat, and processed foods.
• Food safety and quality control in food processing environments.

2. Clinical Microbiology

• Isolation of Bacillus cereus from fecal samples and specimens related to foodborne illnesses.
• Investigating Bacillus cereus infections, including abscess formation, meningitis, septicemia, and wound infections.

3. Environmental Microbiology

• Monitoring Bacillus cereus contamination in food processing facilities and soil samples.

Preparation Instructions

1. Weigh and Suspend: Suspend 40.9 g of Bacillus Cereus Selective Agar Base in 1 liter of distilled water.
2. Mix and Heat: Heat with frequent agitation until the powder is fully dissolved.
3. Sterilize: Autoclave at 121°C for 15 minutes.
4. Supplementation: Cool to 45–50°C and aseptically add the reconstituted Polymyxin B supplement (Oxoid SR0099E).
5. Pour Plates: Pour the medium into sterile Petri dishes and allow it to solidify.

Diagnostic Features

Specifications

Advantages

1. High Selectivity: Suppresses Gram-negative bacteria for more precise Bacillus cereus detection.
2. Reliable Diagnosis: Easily identifies Bacillus cereus colonies with distinct diagnostic features.
3. Versatile Use: Applicable to food safety, environmental, and clinical microbiology.
4. Cost-Effective: High yield ensures economical testing for large sample volumes.

Storage and Stability

• Storage: Store the dehydrated medium in a cool, dry environment at 10–30°C.
• Shelf Life: Refer to the product label for the expiration date.

References

1. Holbrook R. and Anderson J.M. (1980). Can. J. Microbiol., 26 (7): 753-759.
2. Brit. Med. J., 15 January 1972, p. 189.
3. Mortimer P.R. and McCann G., Lancet, 25 May 1974, p. 1043-1045.
4. Bouza E., Grant S., Jordan C., Yook R., and Sulit H. (1979). Arch. Ophthalmol., 97: 498-499.
5. Akesson A., Hedström S.A., and Ripa T. (1991). Scand. J. Inf. Dis., 23: 71-77.

Packaging

• Product: Bacillus Cereus Selective Agar Base (Dehydrated)
• Quantity: 500g
• Yield: 12.2L of prepared medium

The Thermo Scientific™ Oxoid™ Bacillus Cereus Selective Agar Base is a highly effective and reliable medium for detecting, isolating, and enumerating Bacillus cereus in food and clinical samples. Its selective and diagnostic properties, combined with its compatibility with Polymyxin B Supplement, make it indispensable for laboratories focused on food safety, clinical diagnostics, and microbiological research.