Biofilm formation on rat skin wounds by Pseudomonas aeruginosa carrying the green fluorescent protein gene.

Most chronic wounds are covered by biofilms. However, questions remain about whether biofilms are a causative factor in delayed wound healing and whether the biofilm state contributes to this pathology. The purpose of this study was to develop an experimental model for convenient observation of biofilm formation on skin wounds. Full-thickness wounds were created on the backs of SD rats. Suspensions of Pseudomonas aeruginosa carrying the gene encoding green fluorescent protein were then applied to the wounds. The wounds were harvested at 8 h, and at 1, 3 and 7 days postwounding for histological and immunohistochemical examinations. Fluorescence microscopy confirmed the presence of a biofilm as early as 8 h. Comparing with non-infected wounds, epithelialization was not delayed. In conclusion, wound healing of rat acute wounds was unaffected by biofilm formation.