Microorganisms and performance criteria for selective isolation media 'RVS' used in Water quality microbiology according to ISO 11133.
ISO 19250 (2013) medium: RVS
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Qualitative control of Productivity
- Use a quantitative reference material or test suspension with a known number of Salmonella Enteritidis and Salmonella Typhimurium and Escherichia coli.
- Inoculate one tube of test medium with < 100 cells of target microorganisms and with >103 cells of non-target organisms.
- Incubate at (41,5 ± 1) °C for (24 ± 3) h.
- Remove 10 µl and streak to a plate of specific medium for the target organism.
- Incubate at (41,5 ± 1) °C for (24 ± 3) h.
- Growth of target microorganisms should reach "> 10 colonies on XLD or other medium of choice" with a characteristic reaction of: Characteristic colonies according to each medium (see standard).
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1 Qualitative control of Selectivity man
- Use a quantitative reference material or test suspension with a known number of Escherichia coli.
- Inoculate one tube of test medium with >103 cells of non-target organisms.
- Incubate at (41,5 ± 1) °C for (24 ± 3) h.
- Remove 10 µl and streak to a plate of reference medium (TSA).
- Incubate at (41,5 ± 1) °C for (24 ± 3) h.
- Growth of non-target microorganisms should comply with the criteria: "Partial inhibition ≤ 100 colonies on TSA".
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2 Qualitative control of Selectivity man
- Use a quantitative reference material or test suspension with a known number of Enterococcus faecalis.
- Inoculate one tube of test medium with >103 cells of non-target organisms.
- Incubate at (41,5 ± 1) °C for (24 ± 3) h.
- Remove 10 µl and streak to a plate of reference medium (TSA).
- Incubate at (41,5 ± 1) °C for (24 ± 3) h.
- Growth of non-target microorganisms should comply with the criteria: "< 10 colonies on TSA".
Best Practice RVS
Qualitative control of Selectivity of liquid medium, mixed culture
Control strain | WDCM number | Incubation | Criteria | Characteristic reaction | |
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Salmonella Enteritidis | (41,5 ± 1) °C for (24 ± 3) h | > 10 colonies on XLD or other medium of choice | Characteristic colonies according to each medium (see standard) | ||
+ Salmonella Typhimurium | |||||
+ Escherichia coli | or | ||||
+ Pseudomonas aeruginosa | |||||
The best practice for Qualitative control of Productivity for media control of 'RVS' is based on the data displayed in this table according ISO 11133. |
Best Practice RVS
Qualitative control of Selectivity of liquid medium, single culture
Control strain | WDCM number | Ref. media | Incubation | Criteria | Characteristic reaction |
---|---|---|---|---|---|
Escherichia coli | or | TSA | (41,5 ± 1) °C for (24 ± 3) h | Partial inhibition ≤ 100 colonies on TSA | Growth |
The best practice for Qualitative control of Selectivity for media control of 'RVS' is based on the data displayed in this table according ISO 11133. |
Best Practice RVS
Qualitative control of Selectivity of liquid medium, single culture
Control strain | WDCM number | Ref. media | Incubation | Criteria | Characteristic reaction |
---|---|---|---|---|---|
Enterococcus faecalis | or | TSA | (41,5 ± 1) °C for (24 ± 3) h | < 10 colonies on TSA | < 10 colonies on TSA |
The best practice for Qualitative control of Selectivity for media control of 'RVS' is based on the data displayed in this table according ISO 11133. |