Biofilms and microbiome profiles in chronic wounds: links to antibiotic use and wound severity in a Sri Lankan cohort

Abstract

Aims: We have characterized the microbiome of infected chronic diabetic wounds (CDWs), exploring associations with antibiotic use and wound severity in a Sri Lankan cohort.

Methods and results: Fifty CDW patients were enrolled, 38 of whom received antibiotics. Tissue biopsies were analysed by microbiome profiling, and wounds were graded using the University of Texas Wound Grading System. Biofilm presence was assessed in 20 wounds. The microbiome was largely dominated by Enterobacteriaceae, Pseudomonadaceae, Streptococcaceae, and Corynebacteriaceae. Proteobacteria levels were significantly higher in antibiotic-treated wounds (P = .019), with increased Pseudomonas abundance. Wounds were categorized as grade 1 (10), grade 2 (29), and grade 3 (11). Alpha diversity varied by wound grade (P = .015), with grade 2 wounds showing the highest diversity and grade 3 the lowest. All 20 tested wounds were biofilm-positive, and community composition varied more in antibiotic-treated wounds (P = .004).

Conclusions: CDW microbiomes were dominated by Enterobacteriaceae and Pseudomonadaceae, with elevated Proteobacteria in antibiotic-treated wounds. Alpha diversity correlated with wound severity, peaking in grade 2 wounds. The high prevalence of biofilms in wounds underscores the need for management of CDWs that address microbial complexity.

Keywords: antibiotics; bacterial diversity; biofilms; chronic diabetic wounds; microbiome; next-generation sequencing.