ISO 10273 (2017) medium: ITC

Media control Food chain

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

  • 1 Qualitative control of Productivity

  • Best Practice ITC

    Qualitative control of Selectivity of liquid medium, mixed culture

    1. Use a quantitative reference material or test suspension with a known number of Yersinia enterocolitica and Escherichia coli and Pseudomonas aeruginosa.
    2. Inoculate one tube of test medium with < 100 cells of target microorganisms and with >103 cells of non-target organisms.
    3. Incubate at (25 ± 1) °C for (44 ± 4) h.
    4. Remove 10 µl and streak to a plate of specific medium for the target organism.
    5. Incubate at (25 ± 1) °C for (44 ± 4) h.
    6. Growth of target microorganisms should reach "> 10 colonies on CIN or SSDC" with a characteristic reaction of: Characteristic colonies according to each medium (see ISO 10273).

    Control strain WDCM number Incubation Criteria Characteristic reaction
    Yersinia enterocolitica (25 ± 1) °C for (44 ± 4) h > 10 colonies on CIN or SSDC Characteristic colonies according to each medium (see ISO 10273)
    + Escherichia coli or
    + Pseudomonas aeruginosa
    The best practice for Qualitative control of Productivity for media control of 'ITC' is based on the data displayed in this table according ISO 11133.
  • 2 Qualitative control of Productivity

  • Best Practice ITC

    Qualitative control of Selectivity of liquid medium, mixed culture

    1. Use a quantitative reference material or test suspension with a known number of Yersinia enterocolitica and Escherichia coli and Pseudomonas aeruginosa.
    2. Inoculate one tube of test medium with < 100 cells of target microorganisms and with >103 cells of non-target organisms.
    3. Incubate at (25 ± 1) °C for (44 ± 4) h.
    4. Remove 10 µl and streak to a plate of specific medium for the target organism.
    5. Incubate at (25 ± 1) °C for (44 ± 4) h.
    6. Growth of target microorganisms should reach "> 10 colonies on CIN or SSDC" with a Characteristic reaction of: Characteristic colonies according to each medium (see ISO 10273).

    Control strain WDCM number Incubation Criteria Characteristic reaction
    Yersinia enterocolitica (25 ± 1) °C for (44 ± 4) h > 10 colonies on CIN or SSDC Characteristic colonies according to each medium (see ISO 10273)
    + Escherichia coli or
    + Pseudomonas aeruginosa
    The best practice for Qualitative control of Productivity for media control of 'ITC' is based on the data displayed in this table according ISO 11133.
  • Qualitative control of Selectivity

  • Best Practice ITC

    Qualitative control of Selectivity of liquid medium, single culture

    1. Use a quantitative reference material or test suspension with a known number of Pseudomonas aeruginosa and Proteus mirabilis.
    2. Inoculate one tube of test medium with >103 cells of non-target organisms.
    3. Incubate at (25 ± 1) °C for (44 ± 4) h.
    4. Remove 10 µl and streak to a plate of reference medium (TSA).
    5. Incubate at (25 ± 1) °C for (44 ± 4) 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
    Pseudomonas aeruginosa TSA (25 ± 1) °C for (44 ± 4) h Total inhibition (0) on TSA No growth
    + Proteus mirabilis
    The best practice for Qualitative control of Selectivity for media control of 'ITC' is based on the data displayed in this table according ISO 11133.