HCM018 Baird-Parker Agar Base
$32-43
Intended Use For the isolation, presumptive identification and enumeration of Staphylococcus aureus from food and animal feed as well as from other materials. Principle and Interpretation ……
Introduction
Intended Use
For the isolation, presumptive identification and enumeration of Staphylococcus aureus from food and animal feed as well as from other materials.
Principle and Interpretation
Tryptone, beef extract powder and yeast extract powder provides carbon and nitrogen sources, vitamins and growth factors; sodium pyruvate and glycine to stimulate the growth of Staphylococcus aureus; lithium chloride and potassium tellurite inhibit the non-staphylococcal microorganisms; containing lecithinase staphylococcal colonies produce degradation yolk make transparent circle, while the role of the lipase produced an opaque precipitate ring; coagulase-positive staphylococci can restore potassium tellurite and produce black colonies; agar is medium coagulant.
Formulation
| Ingredients | /liter |
| Pancreatic digest of casein （Tryptone） | 10.0g |
| Beef extract | 5.0g |
| Yeast extract | 1.0g |
| Sodium pyruvate | 10.0g |
| Glycine | 12.0g |
| Lithium chloride | 5.0g |
| Agar | 15.0g |
| pH7.0±0.2 at 25°C | |
Preparation
Suspend 58g in 950mL of distilled or deionized water. Heat with frequent agitation and boil to completely dissolve the powder. Distribute into flasks. Autoclave at 121℃ for 15 minutes and then cool to 50℃. Add potassiun tellurite egg-yolk reagent(029195) to 95mL of base medium ,or add potassiun tellurite egg-yolk reagent(029192) to 475mL of base medium. Mix thoroughly and pour into sterile Petri plates.
Quality Control
Cultural characteristics observed after incubation at 35-37°C for 24 hours
| Quality control strains | Growth | Characteristics |
| Staphylococcus aureus ATCC6538 | Good, PR≥0.7 | Black or grey colonies with clear halo |
| Staphylococcus aureus ATCC25923 | ||
| Staphylococcus epidermidis CMCC(B)26069 | No recovery limit | Black or grey colonies without clear halo |
| Escherichia coli ATCC25922 | G≤1 | inhibition |
Storage and Shelf Life
2-30℃，Keep container tightly closed, avoid direct sunlight.
Use before expiry date on the label.
Precautions
1. When weighing the dehydrated medium, please wear masks to avoid causing respiratory system discomfort
2. Keep container tightly closed after using to prevent clumping.
Waste Disposal
Microbiological contamination was disposed by autoclaving at 121°C for 30 minutes.
Revision
On June 14, 2024
References
BAM Media M17
ISO 6888-1-1999_Amd 2-2018. Microbiology of food and animal feeding stuffs — Horizontal method for the enumeration of coagulase-positive staphylococci (Staphylococcus aureus and other species) Part 1: Technique using Baird-Parker agar medium
