Microorganisms and performance criteria for selective isolation media 'SDS' used in Food and animal feeding stuffs microbiology according to ISO 11133.
ISO/ TS 21872-2 (2007) medium: SDS
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Qualitative control of Productivity
- Use a reference material or test suspension with a known number of Vibrio vulnificus and Vibrio cholerae non-O1/non-O139.
- The volume used for testing should contain 103 to 104 cfu for qualitative tests of plate media.
- Streak each test microorganism (Vibrio vulnificus and Vibrio cholerae non-O1/non-O139) on the media under test (SDS) to obtain discrete colonies.
- Incubate at (37 ± 1) °C for (24 ± 3) h.
- Asses the amount of growth as, 0 for no growth, 1 for weak growth or 2 for good growth.
- For this medium (SDS) and standard (ISO/ TS 21872-2) combination the criteria is: "Good growth (2)".
- The Characterictic reaction is: Purple/green colonies with an opaque halo.
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Qualitative control of Selectivity
- Use a reference material or test suspension with a known number of Escherichia coli.
- Streak the test strain (Escherichia coli) as a single line on the media under test (SDS).
- 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.
- Incubate at (37 ± 1) °C for (24 ± 3) h.
- Asses the amount of growth as, 0 for no growth, 1 for weak growth or 2 for good growth.
- For this medium (SDS) and standard (ISO/ TS 21872-2) combination the criteria is: "Total inhibition (0).
Best Practice SDS
Qualitative control of Productivity solid medium
Control strain | WDCM number | Incubation | Criteria | Characteristic reaction | |
---|---|---|---|---|---|
Vibrio vulnificus | (37 ± 1) °C for (24 ± 3) h | Good growth (2) | Purple/green colonies with an opaque halo | ||
+ Vibrio cholerae non-O1/non-O139 | |||||
The best practice for Qualitative control of Productivity for media control of 'SDS' is based on the data displayed in this table according ISO 11133. |
Best Practice SDS
Qualitative control of Selectivity solid medium
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 'SDS' is based on the data displayed in this table according ISO 11133. |