Description
Baird-Parker Agar for Selective Isolation of Coagulase-Positive Staphylococci – Ideal for Food Safety Testing
Detailed Product Description:
Baird-Parker Agar is the ultimate medium for the selective isolation and enumeration of coagulase-positive staphylococci, particularly Staphylococcus aureus. This agar is crucial in microbiology laboratories focused on food safety and pathogen detection, providing a reliable method for identifying bacteria that can cause foodborne illnesses.
Key Ingredients and Benefits:
- Pancreatic Digest of Casein, Beef Extract, Yeast Extract: Essential nutrients that support robust bacterial growth.
- Sodium Pyruvate and Glycine: Stimulate the growth of Staphylococcus aureus, enhancing recovery rates.
- Lithium Chloride and Potassium Tellurite: Selective agents that inhibit the growth of competing flora, ensuring accurate isolation.
- Egg Yolk: Serves as a substrate for detecting lecithinase and lipase activity, critical for identifying pathogenic strains.
Principle of Operation: This medium facilitates the growth of Staphylococcus aureus, which is known for producing heat-resistant enterotoxins. Upon incubation, the agar reveals distinct dark gray to black colonies, indicative of tellurite reduction, while lecithinase-producing strains create clear zones, providing a clear visual differentiation for microbiologists.
Preparation Instructions: To prepare, suspend 58.0g of Baird-Parker Agar in 950mL of distilled water, boil for one minute, sterilize at 121℃ for 15 minutes, then add 10 mL of 1% potassium tellurite and 50 mL of sterile egg yolk suspension before pouring into Petri dishes.
Storage and Shelf Life: Store tightly capped at 5-30°C; dehydrated medium has a shelf life of 3 years. Prepared medium should be kept at 2-8°C and used within 48 hours.
Appearance: Dehydrated Baird-Parker Agar appears as a free-flowing yellowish powder, while the prepared medium is a yellowish opaque gel.
Quality Control: Inoculate and incubate at 36±1℃ for 45-48 hours to verify performance.
| Microorganism | Strains Number | Inoculum
(CFU） |
Recovery | Colony colour | Lecithinase
production(Halos) |
| Staphylococcus Aureus | ATCC 25923 | 20-200 | ≥70% | Black | + |
| Escherichia coli | ATCC 25922 | 102-103 | ≤1% | Inhibited | – |
| Staphylococcus Aureus | ATCC 6538 | 20-200 | ≥70% | Black | + |
| Bacillus subtilis | ATCC 6633 | 102-103 | <30% | Brown | – |
| Proteusmirabilis | ATCC 12453 | 20-200 | ≥50% | Brown-black | – |
| Staphylococcus epidermidis | CMCC(B)26069 | 20-200 | ≥50% | Black-grey | – |
Reviews
There are no reviews yet.