Wound swab

Indications for initiating microbiological analysis of a wound specimen

• Acute or chronic wounds with signs of spreading or systemic⁽¹⁾ infection⁽²⁾
• Infected wounds that have failed to respond to antimicrobial intervention, or are deteriorating despite
  appropriate antimicrobial treatment
• In compliance with local protocols for the surveillance of drug-resistant microbial species
• Wounds where the presence of certain species would negate a surgical procedure (e.g. beta
  haemolytic streptococci in wounds prior to skin grafting)

⁽¹⁾In individuals showing signs of sepsis, blood cultures are also indicated, and other likely sites of infection should be considered
as potential sources of infection. Other samples should be collected for microbiological analysis as relevant (e.g. specimens of urine,
sputum or swab of the tip of a central venous line catheter).

⁽²⁾In immunocompromised patients (e.g. those taking immunosuppressants or corticosteroids, or with diabetes mellitus or peripheral
arterial disease), also consider sampling chronic wounds without signs of local wound infection and/or delayed healing.

Cleanse and debride the wound

• Inform the patient and obtain consent to collect the specimen
• Cleanse the wound using warm sterile normal saline
• Debride non-viable tissue as required and consistent with local policy
• Repeat wound cleansing using warm sterile normal saline

Moisten the swab tip

• Use a wound swab kit provided by the laboratory
• Moisten the swab tip with sterile normal saline

Select the sample location

• Inform the patient that the procedure may cause discomfort
• Using an aseptic technique, firmly press the swab down into the wound and rotate the swab over a 1cm² area to
  express fluid from the tissue
• Repeat the process using a second swab stick to obtain a second sample

Label the sample appropriately

• Check the laboratory request form is complete and accurate
• Provide sufficient information on the request form, including:

• Duration of wound
• Provisional diagnosis of wound status
• Depth of wound
• Relevant clinical history and comorbidities
• Current antibiotic therapy
• Other relevant medication use (e.g. steroids)

• Sharps container
• Disposable gloves
• Sterile normal saline
• Surgical blade
• Swab kit

• Microbiological analysis of a specimen from the wound (known as a wound culture) is performed to identify causative microorganisms and to guide antimicrobial therapy selection after a clinical diagnosis of wound infection has been made.
• Because all wounds are contaminated or colonised with microorganisms, a wound should only be cultured in specific clinical situations (See Sample collection conditions).
• Tissue biopsy is the preferred wound specimen for obtaining accurate cultures.
• Use an inert wound cleanser and debride the wound (if required) prior to collecting a wound specimen to avoid false positive results.