Wound swab

Last updated: Sunday, 28, May, 2006

MBS Online Search Page: Click here for details

Item Process
Specimen

Pus in syringe or sterile container is preferable.

Swab for Gram stain, swab in transport medium for culture.

If fungal culture is required or infection with atypical organisms is suspected, this information should be provided on the request form.

Method

Gram stain for microscopy; culture on enriched, non-selective agar media and in broth.

Identification of significant isolates, followed by appropriate antibiotic sensitivity testing.

Anaerobic culture in selected circumstances.

Application

Investigation of an infected wound or lesion, when clinical assessment suggests that antibiotic treatment or surgical drainage/debridement may be required.

Investigation of wound infection as part of infection control measures in hospitals or other institutions.

Interpretation

Pure growth of a single organism increases the likelihood that it is the pathogen.

Recognised pathogens, eg, Staphylococcus aureus, Streptococcus pyogenes, Clostridium perfringens, are specifically reported, even if there is a mixed growth.

Antibiotic sensitivity tests are performed on recognised pathogens.

Antibiotic treatment is appropriate for infection which is spreading, especially where systemic toxicity is present. The decision to treat a wound infection with antibiotics should be made on clinical grounds, not based on the results of a wound swab. For less serious wound infection, simple drainage may be sufficient.

Reference

Janda JM et al. Eur J Clin Microbiol Infect Dis 1997; 16: 189-201.