Food PT scheme sample instruction sheet

Staphylococcus aureus enterotoxin

The final date for return of results is indicated on the accompanying request/report form

Contact details:
The Organisers - FEPTU
UK Health Security Agency
61 Colindale Avenue,
London, NW9 5EQ, UK.
Tel: +44 (0) 20 8327 7119
e-mail: foodeqa@ukhsa.gov.uk
Results should be returned on-line using the web-based reporting system. Go to: www.phe-eqa.org.uk. You will need your log-in details for this process. Please contact us if you experience problems with the on-line system.

Staphylococcus aureus enterotoxin

Scheme – Instruction Sheet

Each distribution consists of two evacuated glass vials containing a pure culture of freezedried micro-organisms. The vial contents require reconstitution prior to examination.

Refer also to the Safety Data Sheet: Safety data sheet - Freeze-dried format

For a video on sample processing: Processing samples - Staphylococcus aureus Scheme

Storage:

Store the samples at 2 - 8ºC on receipt.

Safety Recommendation:

The samples contain micro-organisms of ACDP Hazard Groups 1 and 2. Your laboratory must undertake a risk assessment before handling these samples with particular consideration to the conditions and procedures for opening evacuated vials to prevent the risk of aerosol.

Opening Vials:

Remove the plastic tear-off seal by positioning the vial with the arrow on the plastic flip-top pointing away from you, flip the top up then carefully but deliberately pull downwards and to the right (or the left if you are left handed) until the seal separates; then still holding onto the plastic top, gently remove altogether and discard into a sharps container.

Reconstitution:

Reconstitute the samples in 100mL nutrient broth (pre-warmed to 30 ± 2oC) as follows:

  • Aseptically remove the rubber stopper from the vial of the freeze-dried sample.
  • Transfer approximately 1mL of the 100mL warmed nutrient broth to the vial and allow to stand for 2 - 5 minutes.
  • Transfer the vial contents back to the remaining nutrient broth.
  • Rinse the vial a further 3 - 4 times with the 100mL nutrient broth sample.
  • Shake the reconstituted samples before examination.

Examination:

  • Incubate the entire reconstituted sample for 22 ± 2 h at 37°C then test the broth for Staphylococcus aureus enterotoxins in accordance with your routine procedures.
  • After incubation, each reconstituted sample is equivalent to a 100g food sample.

Return of Results:

  • Return your results on-line using the web-based reporting system.
  • Return results to the organisers before the deadline shown on the request/report form.
  • Results returned after that date will not be assessed.