ISO 21872-1 (2017) medium: TCBS

Media control Food chain

Microorganisms and performance criteria for selective isolation media 'TCBS' used in Food chain microbiology according to ISO 21872-1.

  • Qualitative control of Productivity

    • Green colonies (sucrose negative). The characteristic reaction of on TCBS
    The characteristic reaction of Vibrio parahaemolyticus on TCBS: Green colonies (sucrose negative).

    Best Practice TCBS

    Qualitative control of Productivity solid medium

    1. Use a reference material or test suspension with a known number of Vibrio parahaemolyticus and Vibrio furnissii.
    2. The volume used for testing should contain 103 to 104 cfu for qualitative tests of plate media.
    3. Streak each test microorganism (Vibrio parahaemolyticus and Vibrio furnissii) on the media under test (TCBS) to obtain discrete colonies.
    4. Incubate at (37 ± 1) °C for (24 ± 3) 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 (TCBS) and standard (ISO 21872-1) combination the criteria is: "Good growth (2)".
    7. The Characterictic reaction is: Green colonies (sucrose negative).

    Control strain WDCM number Incubation Criteria Characteristic reaction
    Vibrio parahaemolyticus
    		(37 ± 1) °C for (24 ± 3) h Good growth (2) Green colonies (sucrose negative)
    + Vibrio furnissii
    The best practice for Qualitative control of Productivity for media control of 'TCBS' is based on the data displayed in this table according ISO 21872-1.

  • Qualitative control of Selectivity

    • Best Practice TCBS

    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 (TCBS).
    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 (37 ± 1) °C for (24 ± 3) 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 (TCBS) and standard (ISO 21872-1) combination the criteria is: "Total inhibition (0).

    Control strain WDCM number Ref. media Incubation Criteria Characteristic reaction
    Escherichia coli
    or
    or
    		(37 ± 1) °C for (24 ± 3) h Total inhibition (0) No growth
    The best practice for Qualitative control of Selectivity for media control of 'TCBS' is based on the data displayed in this table according ISO 21872-1.