Microbiology

Infection Control Screening Specimens

Specimens to be taken for MRSA are:

  • Nose: one swab inserted into both anterior nares (the fleshy part of the nose).
  • Axillae and groins: one swab applied to both axillae AND both groins and labelled axilla/groin.
  • Skin lesions and/or wounds: one swab from each site. Each site must be clearly identified on the individual swab.
  • Insertion sites for devices in-situ at the time of screening such as percutaneous gastrostomy sites or tracheostomy sites.
  • A catheter specimen of urine, (CSU), should be obtained from patients who have a urinary catheter in situ at the time of screening. This must be taken using a correct aseptic technique, from the sampling port, not from the catheter bag.
  • If the patient has been previously MRSA positive, all sites which were identified as positive should be re swabbed, this will include sites such as wounds or stoma site.

Urgent Polymerase Chain Reaction (PCR) MRSA screening

In exceptional circumstances wards/clinical departments can request a rapid MRSA nasal screen using Polymerase Chain Reaction (PCR) technology. A PCR test should only be requested for patients whose current MRSA status is unknown. This test should not be used as a repeat screen for patients who have previously been diagnosed as MRSA positive.

This test will only be undertaken if the ward/department speaks directly to the laboratory, at their specific site, either Hull Royal or Castle Hill Hospital and submits a sample, using a red topped COPAN swab, by 14:00 of the same day Monday to Friday, excluding Bank Holidays. The result will normally be available within an hour and a half.

Samples to be taken for CPE are:

Rectal screen

A rectal swab (using the standard microbiology black charcoal swab) or obtaining a stool specimen; the swab is gently inserted into the rectum and rotated gently. To ensure detection of the organism there should be visible faecal material on the swab. The rectal swabs or stool specimen should be taken on day 1, day 3 and day 5 (3 swabs taken 48 hours apart).

Wound screen

Patients with wounds or lesions should have these swabbed once on day 1

Catheter urine

Patients with urinary catheters should have a catheter specimen of urine taken once on day 1

Device-related sites

Patients with any other devices should have swabs taken of the entry sites once on day 1. Send all samples to the laboratory as soon as possible marking request form: “Possible carbapenamase producing enterobacteriaceae” and give as much information as possible regarding any travel and history

See specific infection prevention and control policies for guidelines