ISO 22964 (2017) medium: CSB

Media control Food chain

Microorganisms and performance criteria for selective enrichment media 'CSB' used in Food chain microbiology according to ISO 22964.

  • 1 Qualitative control of Productivity

    • Best Practice CSB

    Qualitative control of Selectivity of liquid medium, mixed culture

    1. Use a quantitative reference material or test suspension with a known number of Cronobacter sakazakii and Staphylococcus aureus.
    2. Inoculate one tube of test medium with < 100 cells of target microorganisms and with >103 cells of non-target organisms.
    3. Incubate at (41,5 ± 1) °C for (24 ± 2) h.
    4. Remove 10 µl and streak to a plate of specific medium for the target organism.
    5. Incubate at (41,5 ± 1) °C for (24 ± 2) h.
    6. Growth of target microorganisms should reach "Colour change of CSB; >10 colonies on CCI" with a characteristic reaction of: Yellow colour of CSB; Small to mediumsized (1mm to 3mm) blue to bluegreen colonies on CCI.

    Control strain WDCM number Incubation Criteria Characteristic reaction
    Cronobacter sakazakii
    		(41,5 ± 1) °C for (24 ± 2) h Colour change of CSB; >10 colonies on CCI Yellow colour of CSB; Small to mediumsized (1mm to 3mm) blue to bluegreen colonies on CCI
    + Staphylococcus aureus
    or
    The best practice for Qualitative control of Productivity for media control of 'CSB' is based on the data displayed in this table according ISO 22964.

  • 2 Qualitative control of Productivity opt

    • Best Practice CSB

    Qualitative control of Selectivity of liquid medium, mixed culture

    1. Use a quantitative reference material or test suspension with a known number of Cronobacter muytjensii and Staphylococcus aureus.
    2. Inoculate one tube of test medium with < 100 cells of target microorganisms and with >103 cells of non-target organisms.
    3. Incubate at (41,5 ± 1) °C for (24 ± 2) h.
    4. Remove 10 µl and streak to a plate of specific medium for the target organism.
    5. Incubate at (41,5 ± 1) °C for (24 ± 2) h.
    6. Growth of target microorganisms should reach "Colour change of CSB; >10 colonies on CCI" with a Characteristic reaction of: Yellow colour of CSB; Small to mediumsized (1mm to 3mm) blue to bluegreen colonies on CCI.

    Control strain WDCM number Incubation Criteria Characteristic reaction
    Cronobacter muytjensii
    		(41,5 ± 1) °C for (24 ± 2) h Colour change of CSB; >10 colonies on CCI Yellow colour of CSB; Small to mediumsized (1mm to 3mm) blue to bluegreen colonies on CCI
    + Staphylococcus aureus
    or
    The best practice for Qualitative control of Productivity for media control of 'CSB' is based on the data displayed in this table according ISO 22964.

  • Qualitative control of Selectivity

    • Best Practice CSB

    Qualitative control of Selectivity of liquid medium, single culture

    1. Use a quantitative reference material or test suspension with a known number of Staphylococcus aureus.
    2. Inoculate one tube of test medium with >103 cells of non-target organisms.
    3. Incubate at (41,5 ± 1) °C for (24 ± 2) h.
    4. Remove 10 µl and streak to a plate of reference medium (TSA).
    5. Incubate at (41,5 ± 1) °C for (24 ± 2) h.
    6. Growth of non-target microorganisms should comply with the criteria: "Total or partial inhibition on TSA; <100 colonies".

    Control strain WDCM number Ref. media Incubation Criteria Characteristic reaction
    Staphylococcus aureus
    or
    		TSA (41,5 ± 1) °C for (24 ± 2) h Total or partial inhibition on TSA; <100 colonies Purple colour of CSB
    The best practice for Qualitative control of Selectivity for media control of 'CSB' is based on the data displayed in this table according ISO 22964.