Microbial predictors of healing and short-term effect of debridement on the microbiome of chronic wounds

Abstract

Chronic wounds represent a large and growing disease burden. Infection and biofilm formation are two of the leading impediments of wound healing, suggesting an important role for the microbiome of these wounds. Debridement is a common and effective treatment for chronic wounds. We analyzed the bacterial content of the wound surface from 20 outpatients with chronic wounds before and immediately after debridement, as well as healthy skin. Given the large variation observed among different wounds, we introduce a Bayesian statistical method that models patient-to-patient variability and identify several genera that were significantly enriched in wounds vs. healthy skin. We found no difference between the microbiome of the original wound surface and that exposed by a single episode of sharp debridement, suggesting that this debridement did not directly alter the wound microbiome. However, we found that aerobes and especially facultative anaerobes were significantly associated with wounds that did not heal within 6 months. The facultative anaerobic genus Enterobacter was significantly associated with lack of healing. The results suggest that an abundance of facultative anaerobes is a negative prognostic factor in the chronic wound microbiome, possibly due to the increased robustness of such communities to different metabolic environments.

Biofilms in Diabetic Foot Ulcers: Significance and Clinical Relevance

“…However, neither patient demographics nor wound type influenced the bacterial composition of the chronic wound microbiome [ 17 ]. Different studies have described this DFU microbiota [ 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ]. Although they have produced interesting results and confirmed that the microbiota is a highly dynamic microbial community that maintains a relationship with the host, understanding the complex competitive or synergistic interaction between commensal and pathogenic microorganisms is necessary as it could play an important role in the severity and evolution of the wound.…”

Electrospinning Proteins for Wound Healing Purposes: Opportunities and Challenges

“…The interruption in the healing process may occur for a number of reasons connected to one’s lifestyle and health condition. For example, smoking, malnutrition, obesity, low mobility, neuropathy, diabetes, vascular diseases and skin disorders have been linked to the increasing chronicity of wounds, where healing has not been achieved within 3–6 weeks [ 2 , 3 , 4 ].…”

“…The leading causes of non-healing chronic wounds are infection, pathological inflammation and formation of biofilms [ 2 , 6 ]. Therefore, wound care usually comprises of debridement followed by antimicrobial treatment and application of wound dressings.…”

The dynamic wound microbiome

“…Moreover, results from MacDonald et al [ 45 ] suggested that healing DFUs had a higher abundance of Actinomycetales and Staphylococcaceae , while non-healing DFUs showed higher abundances of Bacteroidales and Streptococcaceae . Facultative anaerobes, especially of the genus Enterobacter , were found to be significantly associated with lack of healing, and thus a negative prognostic factor derived from knowing the chronic wound microbiome [ 46 ]. However, despite these trends, no statistically significant correlation was found between wound status (healed versus unhealed) and the abundance of any particular taxa at the species or genus level in several other studies [ 29 , 43 , 47 ].…”

“…Wound debridement and wound dressings have also been shown to significantly modify the wound microbiome in DFU patients, with evidence that this led to favorable outcomes [ 34 ], even for long-term chronic wounds [ 43 ]. However, Verbanic et al [ 46 ] found no difference in the wound microbiome between pre-debridement and 1–2 min post-debridement specimens, suggesting that debridement did not alter the wound microbiome directly in the short term. Notably, in this study, the extent and depth of debridement, as well as the type of instrument used (curette, scalpel, scissors, or tissue nipper), were not standardized and were determined by the treating physician.…”