ISO 16649-3 (2016) method: β-d-Glucuronidasepositive E. coli

Process control Food chain

Horizontal method for the enumeration of beta-glucuronidase-positive Escherichia coli (E. coli) - Part 3: Detection and most probable number technique using 5-bromo-4-chloro-3-indolyl-β-D-glucuronide

  • 1 Qualitative process control with RM-EC

  • Colour change to yellow. The characteristic reaction of  on TBX
    Characteristic reaction: Colour change to yellow.

    Best Practice

    The single strain RM-EC is used for the enumeration of beta-glucuronidase-positive Escherichia coli

    Process control detection method

    1. Use a quantitative reference material (RM-EC) with a known number of Escherichia coli serotype O6:H1.
    2. Defrost the material at room temperature for 30 minutes.
    3. Mix well before use.
    4. In the case of qualitative operations the contamination level of the reference material (RM-EC) must be representative of the limit of detection.
    5. At an average contamination level of 5 cfu per control sample, the probability of using a coincidentally uninfected (negative) sample according to the Poisson spread is less than 1%.
    6. Incubate at (44 ± 1) °C for (21 ± 3) h.
    7. Determine the absence or presence of the microorganism and register your finding in a qualitative control chart.
    8. The characteristic reaction is: Colour change to yellow.

    Kind of reference material Biosisto product for this control method Control Strain WDCM number
    Single-strain reference material Escherichia coli serotype O6:H1 00013
    The Biosisto reference material in this table is used in the best practice for Qualitative process control according ISO 17025.
  • 2 Qualitative process control with RM-ECO.00012MM

  • Colour change to yellow. The characteristic reaction of  on TBX
    Characteristic reaction: Colour change to yellow.

    Best Practice

    The single strain RM-ECO.00012MM is used for the enumeration of beta-glucuronidase-positive Escherichia coli

    Process control detection method

    1. Use a quantitative reference material (RM-ECO.00012MM) with a known number of Escherichia coli.
    2. Defrost the material at room temperature for 30 minutes.
    3. Mix well before use.
    4. In the case of qualitative operations the contamination level of the reference material (RM-ECO.00012MM) must be representative of the limit of detection.
    5. At an average contamination level of 5 cfu per control sample, the probability of using a coincidentally uninfected (negative) sample according to the Poisson spread is less than 1%.
    6. Incubate at (44 ± 1) °C for (21 ± 3) h.
    7. Determine the absence or presence of the microorganism and register your finding in a qualitative control chart.
    8. The characteristic reaction is: Colour change to yellow.

    Kind of reference material Biosisto product for this control method Control Strain WDCM number NCCB number
    Single-strain reference material Escherichia coli 00012 72002
    The Biosisto reference material in this table is used in the best practice for Qualitative process control according ISO 17025.
  • 3 Qualitative process control with RM-ECO.00012BH

  • Colour change to yellow. The characteristic reaction of  on TBX
    Characteristic reaction: Colour change to yellow.

    Best Practice

    The single strain RM-ECO.00012BH is used for the enumeration of beta-glucuronidase-positive Escherichia coli

    Process control detection method

    1. Use a quantitative reference material (RM-ECO.00012BH) with a known number of Escherichia coli.
    2. Defrost the material at room temperature for 30 minutes.
    3. Mix well before use.
    4. In the case of qualitative operations the contamination level of the reference material (RM-ECO.00012BH) must be representative of the limit of detection.
    5. At an average contamination level of 5 cfu per control sample, the probability of using a coincidentally uninfected (negative) sample according to the Poisson spread is less than 1%.
    6. Incubate at (44 ± 1) °C for (21 ± 3) h.
    7. Determine the absence or presence of the microorganism and register your finding in a qualitative control chart.
    8. The characteristic reaction is: Colour change to yellow.

    Kind of reference material Biosisto product for this control method Control Strain WDCM number NCCB number
    Single-strain reference material Escherichia coli 00012 72002
    The Biosisto reference material in this table is used in the best practice for Qualitative process control according ISO 17025.
  • 4 Qualitative process control with RM-ECO.00013BL

  • Colour change to yellow. The characteristic reaction of  on TBX
    Characteristic reaction: Colour change to yellow.

    Best Practice

    The single strain RM-ECO.00013BL is used for the enumeration of beta-glucuronidase-positive Escherichia coli

    Process control detection method

    1. Use a quantitative reference material (RM-ECO.00013BL) with a known number of Escherichia coli.
    2. Defrost the material at room temperature for 30 minutes.
    3. Mix well before use.
    4. In the case of qualitative operations the contamination level of the reference material (RM-ECO.00013BL) must be representative of the limit of detection.
    5. At an average contamination level of 5 cfu per control sample, the probability of using a coincidentally uninfected (negative) sample according to the Poisson spread is less than 1%.
    6. Incubate at (44 ± 1) °C for (44 ± 1) °C.
    7. Determine the absence or presence of the microorganism and register your finding in a qualitative control chart.
    8. The characteristic reaction is: Colour change to yellow.

    Kind of reference material Biosisto product for this control method Control Strain WDCM number
    Single-strain reference material Escherichia coli 00013
    The Biosisto reference material in this table is used in the best practice for Qualitative process control according ISO 17025.
  • 5 Qualitative process control with RM-BLES

  • Colour change to yellow. The characteristic reaction of  on TBX
    Characteristic reaction: Colour change to yellow.

    Best Practice

    The multi-strain RM-BLES contains, Bacillus cereus, Lactobacillus plantarum, Escherichia coli WDCM 00013 and Staphylococcus aureus WDCM 00034 in milk. This material can be used for several specific standards. The influence of interfering bacteria is also performed. It is easy to use by making one serie of dilution.

    Process control detection method

    1. Use a quantitative reference material (RM-BLES) with a known number of Microorganisms.
    2. Defrost the material at room temperature for 30 minutes.
    3. Mix well before use.
    4. In the case of qualitative operations the contamination level of the reference material (RM-BLES) must be representative of the limit of detection.
    5. At an average contamination level of 5 cfu per control sample, the probability of using a coincidentally uninfected (negative) sample according to the Poisson spread is less than 1%.
    6. Incubate at (44 ± 1) °C for (21 ± 3) h.
    7. Determine the absence or presence of the microorganism and register your finding in a qualitative control chart.
    8. The characteristic reaction is: Colour change to yellow.

    Kind of reference material Biosisto product for this control method Control Strain WDCM number NCCB number
    Multi-strain reference material Bacillus cereus 100292
    Lactobacillus plantarum 100293
    Escherichia coli serotype O6:H1 00013 100297
    Staphylococcus aureus 00034 100294
    The Biosisto reference material in this table is used in the best practice for Qualitative process control according ISO 17025.