No need for biopsies: comparison of three sample techniques for wound microbiota determination

Abstract

The aim of the study was to compare three sampling techniques used in routine diagnostics to identify the microbiota in chronic venous leg ulcers. A total of 46 patients with persisting venous leg ulcers were included in the study. At inclusion, swab, biopsy and filter paper pad samples were collected. After 4 weeks, additional biopsy and filter paper pad samples were collected. Bacteria were isolated and identified at species level by standard methods. The most common bacterial species detected was Staphylococcus aureus found in 89% of the ulcers. No methicillin-resistant S. aureus isolates were found. We did not find any significant differences regarding the bacterial species isolated between the three sampling techniques. However, using multiple techniques led to identification of more species. Our study suggests that it is sufficient to use swab specimens to identify the bacterial species present in chronic wounds, thus avoiding complications during and after biopsy sampling.

Association Between Microbial Bioburden and Healing Outcomes in Venous Leg Ulcers: A Review of the Evidence

“…10,14 Fewer studies comment on anaerobes and the rigor of anaerobic cultivation methods vary widely, but even these studies disagree on the association of anaerobes with healing. 24,34,35,37 Results for Streptococcus species are most consistent, with most studies showing association with ulcers of increased size, longer duration, and healing delay. 24,[34][35][36] Interestingly, the studies that did not find associations between bacterial populations and healing were more likely to exclude patients with clinical signs of infection in the study design (Table 1 vs. Table 2).…”

“…24,34,35 However, there are studies that associate S. aureus both with delayed healing 14,36 and smaller, healing ulcers. 23,37 Similarly, Pseudomonas species have been associated both with larger ulcers and delayed healing, 24,[34][35][36]38 whereas other (although fewer) studies have found that ulcers harboring Pseudomonas were more likely to heal normally. 10,14 Fewer studies comment on anaerobes and the rigor of anaerobic cultivation methods vary widely, but even these studies disagree on the association of anaerobes with healing.…”

“…Overall, cultivation methods have been shown to be comparable between biopsies and swabs for aerobes, although there are more discrepancies for anaerobes and overall quantities of bacteria, suggesting uneven vertical distribution of at least some species as discussed in the Intra-and Interwound Variation section. 23,25,37,40 Molecular-based studies performed to date have predominantly used sharp debridement samples without comparison of different sampling methods or indication of the depth of the wound sampled.…”

A systematic literature review of the human skin microbiome as biomarker for dermatological drug development

“…The role of the skin microbiome in UC was explored in 10 different studies, Table 1 37, 38, 39, 40, 41, 42, 43, 44, 45, 46. Current research into UC microbiome, comprises larger, longitudinal studies, compared to those in PV and HS.…”

Knowledge and practice of nurses about care for patients with wounds

“…However, this method is not available in all health establishments. 10 culture by swab is used universally due to the fact of being non-invasive, costly and not easy to perform. However, the results may indicate only colonization of the wound, as samples are not always properly obtained.…”