ISO / TS 11059 (2009) method: Pseudomonas spp.

Process control Milk and milk products

Method for the enumeration of Pseudomonas spp.

  • 1 Quantitative process control with CRM-PF

    • Best Practice

    The single strain CRM-PF is used for the enumeration of Pseudomonas spp.

    1. Use a quantitative reference material (CRM-PF) with a known number of Pseudomonas fluorescens.
    2. Defrost the material at room temperature for 30 minutes.
    3. Mix well before use and dilute the material so countable numbers are inoculated on the media (PPA) by spread plate method.
    4. Best results are obtained when a practicable range of 80 cfu to 120 cfu per plate with a minimum number of 50 cfu per plate is used.
    5. Incubate at (25 ± 1) °C for (48 ± 2) h.
    6. Count the colony forming units and register in a control chart.
    7. The characteristic reaction is: Growth.

    Kind of reference material Biosisto product for this control method Control Strain NCCB number
    Single-strain reference material
    CRM-PF
    		 Pseudomonas fluorescens 100423
    The Biosisto reference material in this table is used in the best practice for Quantitative process control according ISO 17025.

  • 2 Quantitative process control with RM-PA

    • Best Practice

    The single strain RM-PA is used for the enumeration of Pseudomonas spp.

    1. Use a quantitative reference material (RM-PA) with a known number of Pseudomonas aeruginosa.
    2. Defrost the material at room temperature for 30 minutes.
    3. Mix well before use and dilute the material so countable numbers are inoculated on the media (PPA) by spread plate method.
    4. Best results are obtained when a practicable range of 80 cfu to 120 cfu per plate with a minimum number of 50 cfu per plate is used.
    5. Incubate at (25 ± 1) °C for (48 ± 2) h.
    6. Count the colony forming units and register in a control chart.
    7. The characteristic reaction is: Growth.

    Kind of reference material Biosisto product for this control method Control Strain WDCM number
    Single-strain reference material
    RM-PA
    		 Pseudomonas aeruginosa 00026
    The Biosisto reference material in this table is used in the best practice for Quantitative process control according ISO 17025.