All wounds are colonized with microorganisms. Cultures should not be obtained from wounds that are not clinically infected (i.e., absence of classical signs of inflammation or purulence or increasing pain). For wounds that are clinically infected, the ideal specimens for culture are deep specimens that are obtained through biopsy or deep curettage following cleansing/debridement of the wound. Laboratories should consider use of screening criteria to reject such swabs without proceeding to culture. For superficial swab specimens that are processed/cultured, interpretation of the results should be correlated with the Gram stain.

Conditions: Wounds infection, skin ulcers

Diagnostic Tests: Superficial skin swabs, wound swabs

Sources

• Chakraborti C, Le C, Yanofsky A. Sensitivity of superficial cultures in lower extremity wounds. J Hosp Med. 2010 Sep;5(7):415-20. (PubMed)
• Gardner SE, Haleem A, Jao YL, et al. Cultures of diabetic foot ulcers without clinical signs of infection do not predict outcomes. Diabetes Care. 2014 Oct;37(10):2693-701. (PubMed)
• Lipsky BA, Berendt AR, Cornia PB, et al. 2012 Infectious Diseases Society of America clinical practice guideline for the diagnosis and treatment of diabetic foot infections. Clin Infect Dis. 2012 Jun;54(12):e132-73. (PubMed)
• Matkoski C, Sharp SE, Kiska DL. Evaluation of the Q score and Q234 systems for cost-effective and clinically relevant interpretation of wound cultures. J Clin Microbiol. 2006 May;44(5):1869-72. (PubMed)