ISO 10272-2 (2017) medium: mCCDA

Media control Food chain

Microorganisms and performance criteria for testing selective media 'mCCDA' for Enumeration of Campylobacter used in Food chain microbiology according to ISO 10272-2.

  • Quantitative control of Productivity

  • Greyish, flat and moist colonies, sometimes with metallic sheen. The characteristic reaction of  on mCCDA
    The characteristic reaction of Campylobacter jejuni on mCCDA: Greyish, flat and moist colonies, sometimes with metallic sheen.

    Best Practice mCCDA

    Quantitative control of Productivity solid medium

    1. Use a quantitative reference material or test suspension with a known number of Campylobacter jejuni.
    2. Dilute this material so 50 to 120 cfu is inoculated on the mCCDA by spreading for example 0.1 mL.
    3. Do this also for the reference media (Blood agar).
    4. Incubate at (41,5 ± 1) °C for (44 ± 4) h.
    5. Count the colonies on the medium under test (mCCDA) and the reference media (Blood agar).
    6. Calculate the productivity ratio PR. The criteria is: PR ≥ 0,5.
    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 (mCCDA) is divided by the total count of colonies obtained on the defined reference medium (Blood agar).
    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
    Campylobacter jejuni or Blood agar (41,5 ± 1) °C for (44 ± 4) h
    microaerobic atmosphere
    PR ≥ 0,5 Greyish, flat and moist colonies, sometimes with metallic sheen
    Campylobacter coli
    The best practice for Quantitative control of Productivity for media control of 'mCCDA' is based on the data displayed in this table according ISO 10272-2.
  • 1 Qualitative control of Selectivity

  • Best Practice mCCDA

    Qualitative control of Selectivity solid medium

    1. Use a reference material or test suspension with a known number of Escherichia coli.
    2. Streak the test strain (Escherichia coli) as a single line on the media under test (mCCDA).
    3. Use a 1 µl loop in case of a concentration of at least 10000 cfu or a 10 µl loop in case of a concentration between 1000 and 10000 cfu.
    4. Incubate at (41,5 ± 1) °C for (44 ± 4) h.
    5. Asses the amount of growth as, 0 for no growth, 1 for weak growth or 2 for good growth.
    6. For this medium (mCCDA) and standard (ISO 10272-2) combination the criteria is: "Total or partial inhibition (0-1).

    Control strain WDCM number Ref. media Incubation Criteria Characteristic reaction
    Escherichia coli or (41,5 ± 1) °C for (44 ± 4) h
    microaerobic atmosphere
    Total or partial inhibition (0-1) No characteristic colonies
    The best practice for Qualitative control of Selectivity for media control of 'mCCDA' is based on the data displayed in this table according ISO 10272-2.
  • 2 Qualitative control of Selectivity opt

  • Best Practice mCCDA

    Qualitative control of Selectivity solid medium

    1. Use a reference material or test suspension with a known number of Staphylococcus aureus.
    2. Streak the test strain (Staphylococcus aureus) as a single line on the media under test (mCCDA).
    3. Use a 1 µl loop in case of a concentration of at least 10000 cfu or a 10 µl loop in case of a concentration between 1000 and 10000 cfu.
    4. Incubate at (41,5 ± 1) °C for (44 ± 4) h.
    5. Asses the amount of growth as, 0 for no growth, 1 for weak growth or 2 for good growth.
    6. For this medium (mCCDA) and standard (ISO 10272-2) combination the criteria is: "Total inhibition (0)".

    Control strain WDCM number Ref. media Incubation Criteria Characteristic reaction
    Staphylococcus aureus (41,5 ± 1) °C for (44 ± 4) h
    microaerobic atmosphere
    Total inhibition (0) No growth
    The best practice for Qualitative control of Selectivity for media control of 'mCCDA' is based on the data displayed in this table according ISO 10272-2.