Hi Kim,
Great to hear from you! We recently updated our topic "Wound Culture - Swabs, Biopsies, Needle Aspiration", according to the 2022 International Consensus Update by the International Wound Infection Institute (IWII).
According to the consensus and published evidence:
- Because of its superior effectiveness and accuracy, wound biopsy is still considered the gold standard for wound culture. However, wound biopsies are relatively invasive, costly, require skilled operators and potentially exacerbate infection. As a result, wound biopsies are not routinely performed in practice.
- Instead, when a wound infection is first suspected, the IWII consensus suggests clinicians collect a wound swab using the Levine technique due to its widespread availability and relatively lower cost. For wounds with antibiotic-resistant species, and to determine the effect of antimicrobial intervention, a wound biopsy is preferred though.
- A wound culture of a swab collected with the Levine technique correctly identifies 80-90% of infected chronic wounds, but it misses 10-20%. On the other hand, the test can correctly confirm that ~50% of non-infected wounds are not infected indeed, but the test is incorrect about 50% of the time.
- Because standard techniques have limitations that prevent many microorganisms from being cultured, new molecular and imaging technologies have been developed but those are not yet widely available (e.g. PCR assays, DNA sequencing techniques). DNA sequencing techniques can more precisely identify microbial species in a wound specimen, including microbes not identified by culture-based techniques.
- So, for patients with clinical signs of infection but "no bacterial growth" in conventional wound culture, clinicians might opt for PCR assays (DNA sequencing) to identify the presence of bacterial pathogen
Hope this helps!
References:
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https://woundreference.com/app/topic?id=wound-culture-
https://www.woundsinternational.com/download/resource/9203