Changing flora in burn and trauma units: experience in the United Kingdom.

Bacterial colonization of burned and devitalized tissue is inevitable. The types of organisms that are isolated from burn wounds depend on such factors as preexisting illness, types of topical antiseptics and antimicrobials used, microbial sampling techniques, and indigenous flora that inhibit the burn unit. Among organisms that are capable of producing disease, Staphylococcus aureus remains the most common isolate in the patient with burns. The decrease in the prevalence of Pseudomonas aeruginosa, which was initiated by the advent of effective topical antiseptics, appears to have continued to the present. Acinetobacter is now a common organism in the burn unit; although the organism has developed resistance to multiple antimicrobial agents, it infrequently causes serious problems. Comparisons between burn units with intensive-care capability that practice an aggressive approach to surgical management and burn units that continue to use a more traditional approach have revealed little difference with regard to incidence of or time to acquisition of potentially pathogenic bacteria. In a recent comparison that involved a unit of each type, marked reductions in the incidence of isolation of P. aeruginosa and Streptococcus group A organisms were observed over the course of 2 years in both of the units. Significant problems with viruses, yeasts, and fungi have not yet been encountered (or identified) in burn units; further study of the potential role of such organisms in infection in the patient with burns is required.