Objective To investigate the relationship between patient outcomes and biofilms in chronic wound infections, and to analyze the effects of microbial diversity and population dynamics on wound prognosis at different stages of chronic wound formation.

Methods We enrolled 104 patients with wound infections from West China Hospital, Sichuan University. According to the wound type, patients were divided into a trauma group (n = 56) and an ulcer group (n = 48). Based on treatment outcomes, patients were also divided into an improvement group (n = 14) and a deterioration group (n = 73). Microbial diversity analysis of wound biofilms was performed using conventional clinical microbial culture combined with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and 16S ribosomal RNA (rRNA) gene amplicon sequencing. The sequencing results were analyzed using bioinformatics techniques, including amplicon sequence variant (ASV) analysis and differential species analysis.

Results A total of 185 pathogen isolates, comprising 76 different species, were obtained from all wound samples using conventional microbial culture. A total of 33511 ASVs were identified by 16S rRNA gene amplicon sequencing. Among these, 22791 ASVs were unique to the improvement group, 5365 ASVs were unique to the deterioration group, and 5355 ASVs were shared by both groups. The abundance of Klebsiella, Providencia, Stenotrophomonas, and Streptococcus were significantly higher in the improvement group than that in the deterioration group, while the abundance of Finegoldia, Peptoniphilus, Porphyromonas, and Prevotella were significantly higher in the deterioration group than that in the improvement group. Analysis of the trauma and ulcer groups across phylum, class, order, family, genus, and species levels using 16S rRNA gene amplicon sequencing revealed greater differences between the two groups in the pathogens identified at the species level. Predominant species in the trauma group included Anaerococcus vaginalis, Porphyromonas asaccharolytica, and Prevotella buccalis, while the ulcer group mainly featured Corynebacterium auriscanis, Corynebacterium striatum, and Anaerococcus vaginalis.

Conclusion 16S rRNA gene amplicon sequencing provides complementary information to traditional identification methods. Differences in the composition of microbial communities in biofilms may be closely associated with the formation of chronic wounds. Differences in microbial structure, variations in abundance, and differences in functional genes within biofilms may have important effects on wound outcomes.