ISO 11290-1 (2017) medium: Fraser

Media control Food chain

Microorganisms and performance criteria for selective enrichment media 'Fraser' used in Food chain microbiology according to ISO 11133.

  • 1 Qualitative control of Productivity

  • Best Practice Fraser

    Qualitative control of Selectivity of liquid medium, mixed culture

    1. Use a quantitative reference material or test suspension with a known number of Listeria monocytogenes 4b and Escherichia coli and Enterococcus faecalis.
    2. Inoculate one tube of test medium with < 100 cells of target microorganisms and with >103 cells of non-target organisms.
    3. Incubate at (37 ± 1) °C for (48 ± 2) h.
    4. Remove 10 µl and streak to a plate of specific medium for the target organism.
    5. Incubate at (37 ± 1) °C for (48 ± 2) h.
    6. Growth of target microorganisms should reach "> 10 colonies on Agar Listeria according to Ottaviani and Agosti" with a characteristic reaction of: Blue green colonies with opaque halo.

    Control strain WDCM number Incubation Criteria Characteristic reaction
    Listeria monocytogenes 4b (37 ± 1) °C for (48 ± 2) h > 10 colonies on Agar Listeria according to Ottaviani and Agosti Blue green colonies with opaque halo
    + Escherichia coli or
    + Enterococcus faecalis or
    The best practice for Qualitative control of Productivity for media control of 'Fraser' is based on the data displayed in this table according ISO 11133.
  • 2 Qualitative control of Productivity opt

  • Best Practice Fraser

    Qualitative control of Selectivity of liquid medium, mixed culture

    1. Use a quantitative reference material or test suspension with a known number of Listeria monocytogenes 1/2a and Escherichia coli and Enterococcus faecalis.
    2. Inoculate one tube of test medium with < 100 cells of target microorganisms and with >103 cells of non-target organisms.
    3. Incubate at (37 ± 1) °C for (48 ± 2) h.
    4. Remove 10 µl and streak to a plate of specific medium for the target organism.
    5. Incubate at (37 ± 1) °C for (48 ± 2) h.
    6. Growth of target microorganisms should reach "> 10 colonies on Agar Listeria according to Ottaviani and Agosti" with a Characteristic reaction of: Blue green colonies with opaque halo.

    Control strain WDCM number Incubation Criteria Characteristic reaction
    Listeria monocytogenes 1/2a (37 ± 1) °C for (48 ± 2) h > 10 colonies on Agar Listeria according to Ottaviani and Agosti Blue green colonies with opaque halo
    + Escherichia coli or
    + Enterococcus faecalis or
    The best practice for Qualitative control of Productivity for media control of 'Fraser' is based on the data displayed in this table according ISO 11133.
  • 1 Qualitative control of Selectivity man

  • Best Practice Fraser

    Qualitative control of Selectivity of liquid medium, single culture

    1. Use a quantitative reference material or test suspension with a known number of Escherichia coli.
    2. Inoculate one tube of test medium with >103 cells of non-target organisms.
    3. Incubate at (37 ± 1) °C for (48 ± 2) h.
    4. Remove 10 µl and streak to a plate of reference medium (TSA).
    5. Incubate at (37 ± 1) °C for (48 ± 2) h.
    6. Growth of non-target microorganisms should comply with the criteria: "Total inhibition (0) on TSA".

    Control strain WDCM number Ref. media Incubation Criteria Characteristic reaction
    Escherichia coli or TSA (37 ± 1) °C for (48 ± 2) h Total inhibition (0) on TSA No growth
    The best practice for Qualitative control of Selectivity for media control of 'Fraser' is based on the data displayed in this table according ISO 11133.
  • 2 Qualitative control of Selectivity man

  • Best Practice Fraser

    Qualitative control of Selectivity of liquid medium, single culture

    1. Use a quantitative reference material or test suspension with a known number of Enterococcus faecalis.
    2. Inoculate one tube of test medium with >103 cells of non-target organisms.
    3. Incubate at (37 ± 1) °C for (48 ± 2) h.
    4. Remove 10 µl and streak to a plate of reference medium (TSA).
    5. Incubate at (37 ± 1) °C for (48 ± 2) h.
    6. Growth of non-target microorganisms should comply with the criteria: "< 100 colonies on TSA".

    Control strain WDCM number Ref. media Incubation Criteria Characteristic reaction
    Enterococcus faecalis or TSA (37 ± 1) °C for (48 ± 2) h < 100 colonies on TSA Growth
    The best practice for Qualitative control of Selectivity for media control of 'Fraser' is based on the data displayed in this table according ISO 11133.