Description

Staphylococcus aureus Chromogenic Medium: Rapid Detection for Food Safety

The Staphylococcus aureus Chromogenic Medium serves as an effective solution for the rapid detection of Staphylococcus aureus in various food products, including water, milk, ice cream, and meat. With results available within 24 hours, this medium plays a crucial role in ensuring food safety. The formulation produces distinct blue-green colonies of Staphylococcus aureus, enabling laboratory technicians to identify contamination quickly. For more related products, visit our [Chromogenic Medium Series].

Key Features and Benefits

One standout feature of this chromogenic medium is its selective inhibition of most Gram-negative bacteria, while facilitating the growth of Listeria, which appears purple. This selectivity enhances the reliability of results and allows for accurate assessments of food products. Additionally, the final pH of the medium ranges from 7.2 to 7.4 at 25℃, creating an optimal environment for the growth of Staphylococcus aureus.

Ingredients and Preparation

The composition of the medium includes:

• Nutrients: 25.0 g/L
• Chromogenic Reagent: 40.3 g/L
• Agar: 15.0 g/L
• Bacteriostatic Agent: 6.0 g/L

To prepare the medium, suspend 17.26 grams in 200 mL of distilled water. Boil the mixture for 2-3 minutes and allow it to cool to 50℃ before pouring into sterile petri dishes. This straightforward preparation process makes it accessible for laboratories aiming to enhance their food safety testing capabilities.

Testing Procedures

For effective detection, you can employ two methods: the coating method and the streak method.

1. Coating Method: After preparing the sample solution according to standard guidelines, transfer 1 mL of the sample onto the center of the agar plate. Use an L-shaped glass rod to coat the sample evenly, avoiding the edges. Incubate the plate inverted at 36 ± 1℃ for 18-24 hours to observe distinct blue-green colonies indicative of Staphylococcus aureus.
2. Streak Method: Similarly, using 10-20 µL of the sample solution, streak the solidified agar plates. Incubate under the same conditions and expect to see protuberant blue-green colonies of Staphylococcus aureus within the specified timeframe.

Quality Control and Storage

Quality control is essential for obtaining reliable results. The dehydrated powder should appear homogeneous with a pale yellow or pink hue, while prepared medium will be colorless. Test against established strains, such as Staphylococcus aureus ATCC25923, ensures consistent performance.

For storage, keep prepared plates in a cool, dark environment for up to five days. Meanwhile, store the powdered medium at 2-8℃. Avoid exposure to light, as it can impact the medium’s effectiveness.

In conclusion, the Staphylococcus aureus Chromogenic Medium provides rapid detection for food safety while incorporating ease of use and reliable quality control measures. By streamlining the testing process, it ensures that any potential risks are identified swiftly and accurately. For more related products, visit our [Chromogenic Medium Series].