Microorganisms and performance criteria for selective enrichment media 'Preston broth' used in Food chain microbiology according to ISO 10272-1.
ISO 10272-1 (2017) medium: Preston broth
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1 Qualitative control of Productivity
- Use a quantitative reference material or test suspension with a known number of Campylobacter jejuni and Escherichia coli and Proteus mirabilis.
- Inoculate one tube of test medium with < 100 cells of target microorganisms and with >103 cells of non-target organisms.
- Incubate at (37 ± 1) °C then (41,5 ± 1) °C for (5 ± 1) h then 44 ± 4) h.
- Remove 10 µl and streak to a plate of specific medium for the target organism.
- Incubate at (37 ± 1) °C then (41,5 ± 1) °C for (5 ± 1) h then 44 ± 4) h.
- Growth of target microorganisms should reach ">10 characteristic colonies on mCCD agar" with a characteristic reaction of: Greyish, flat and moist, sometimes with metallic sheen.
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2 Qualitative control of Productivity opt
- Use a quantitative reference material or test suspension with a known number of Campylobacter coli and Escherichia coli and Proteus mirabilis.
- Inoculate one tube of test medium with < 100 cells of target microorganisms and with >103 cells of non-target organisms.
- Incubate at (37 ± 1) °C then (41,5 ± 1) °C for (5 ± 1) h then 44 ± 4) h.
- Remove 10 µl and streak to a plate of specific medium for the target organism.
- Incubate at (37 ± 1) °C then (41,5 ± 1) °C for (5 ± 1) h then 44 ± 4) h.
- Growth of target microorganisms should reach ">10 characteristic colonies on mCCD agar" with a Characteristic reaction of: Greyish, flat and moist, sometimes with metallic sheen.
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Qualitative control of Selectivity
- Use a quantitative reference material or test suspension with a known number of Escherichia coli and Proteus mirabilis.
- Inoculate one tube of test medium with >103 cells of non-target organisms.
- Incubate at (37 ± 1) °C then (41,5 ± 1) °C for (5 ± 1) h then 44 ± 4) h.
- Remove 10 µl and streak to a plate of reference medium (TSA).
- Incubate at (37 ± 1) °C then (41,5 ± 1) °C for (5 ± 1) h then 44 ± 4) h.
- Growth of non-target microorganisms should comply with the criteria: "Total inhibition (0) on TSA".
Best Practice Preston broth
Qualitative control of Selectivity of liquid medium, mixed culture
Control strain | WDCM number | Incubation | Criteria | Characteristic reaction | |
---|---|---|---|---|---|
Campylobacter jejuni | or | (37 ± 1) °C then (41,5 ± 1) °C for (5 ± 1) h then 44 ± 4) h microaerobic atmosphere |
>10 characteristic colonies on mCCD agar | Greyish, flat and moist, sometimes with metallic sheen | |
+ Escherichia coli | or | ||||
+ Proteus mirabilis | |||||
The best practice for Qualitative control of Productivity for media control of 'Preston broth' is based on the data displayed in this table according ISO 10272-1. |
Best Practice Preston broth
Qualitative control of Selectivity of liquid medium, mixed culture
Control strain | WDCM number | Incubation | Criteria | Characteristic reaction | |
---|---|---|---|---|---|
Campylobacter coli | (37 ± 1) °C then (41,5 ± 1) °C for (5 ± 1) h then 44 ± 4) h microaerobic atmosphere |
>10 characteristic colonies on mCCD agar | Greyish, flat and moist, sometimes with metallic sheen | ||
+ Escherichia coli | or | ||||
+ Proteus mirabilis | |||||
The best practice for Qualitative control of Productivity for media control of 'Preston broth' is based on the data displayed in this table according ISO 10272-1. |
Best Practice Preston broth
Qualitative control of Selectivity of liquid medium, single culture
Control strain | WDCM number | Ref. media | Incubation | Criteria | Characteristic reaction |
---|---|---|---|---|---|
Escherichia coli | or | TSA | (37 ± 1) °C then (41,5 ± 1) °C for (5 ± 1) h then 44 ± 4) h microaerobic atmosphere |
Total inhibition (0) on TSA | No growth |
+ Proteus mirabilis | |||||
The best practice for Qualitative control of Selectivity for media control of 'Preston broth' is based on the data displayed in this table according ISO 10272-1. |