ISO 4833-1 (2013) medium: PCA

Media control Food chain

Microorganisms and performance criteria for testing non-selective media 'PCA' for Enumeration of Colony Count used in Food chain microbiology according to ISO 11133.

  • Quantitative control of Productivity

  • Best Practice PCA

    Quantitative control of Productivity solid medium

    1. Use a quantitative reference material or test suspension with a known number of Escherichia coli and Bacillus subtilis subs. Spizizenii.
    2. Dilute this material so 50 to 120 cfu is inoculated on the PCA by pouring for example 1 mL.
    3. Do this also for the reference media (TSA).
    4. Incubate at (30 ± 1) °C for (72 ± 3) h.
    5. Count the colonies on the medium under test (PCA) and the reference media (TSA).
    6. Calculate the productivity ratio PR. The criteria is: PR ≥ 0,7.
    7. If the PR exceeds 1,4 identify the reason.
    8. For this the total count of colonies obtained on the culture medium under test (PCA) is divided by the total count of colonies obtained on the defined reference medium (TSA).
    Calculate the productivity ratio PR as follows: PR  NS
    N0
    Ns = total count test medium
    N0 = total count reference medium

    Control strain WDCM number Ref. media Incubation Criteria Characteristic reaction
    Escherichia coli TSA (30 ± 1) °C for (72 ± 3) h PR ≥ 0,7 Growth
    + Bacillus subtilis subs. Spizizenii
    Staphylococcus aureus
    The best practice for Quantitative control of Productivity for media control of 'PCA' is based on the data displayed in this table according ISO 11133.