Causes of colonization of autografted burn wounds

The progression of autograft colonization to infection presents significant problems in the care of grafted burn wounds. To determine whether graft colonization arises from self-contamination or from some exogenous source, we characterized pregraft and graft Candida albicans isolates through serotyping and biotyping (Leicester system) and Pseudomonas aeruginosa isolates through serotyping (Japan Pseudomonas aeruginosa Society system). In 21 of 24 patients, the serotype/biotype of the graft isolate was the same as the serotype/biotype of a C. albicans strain previously isolated from the same patient. Fifteen of 16 P. aeruginosa graft contaminants also showed the same serotype as that in a pregraft isolate. Therefore, whereas it has long been surmised that the grafts of patients with burns are self-colonized, this study provides definite data showing that most C. albicans and P. aeruginosa autograft isolates are indeed self-contaminants.