The prompt demonstration without culturing of gram-negative bacteria in burn wound infections

Abstract

Burn wound sepsis is the most important factor in the morbidity and mortality associated with major burns. Blood cultures often give false negative results and wound biopsy is a much more accurate and reliable means of assessing the burn's microbial status. From 1950 to 1965, due to the introduction of antibiotics, gram-negative organisms became predominant among those recovered from burn wound infections. Although few grampositive organisms are now seen in Gram-stained burn wound biopsies, the light pink or red staining of gram-negative organisms can occasionally go unnoticed (Fig. 1). This is not the case when the biopsy sections are stained with the new positive PATS stain developed in our laboratories for gram-negative bacteria. This reaction deposits silver on the lipopolysaccharides of the outer walls of gram-negative, but not gram-positive, bacteria. The assessment of the microbial content of the specimen site as colonized, infected, or having mixed or unmixed gram-negative microbes is facilitated by this stain (Figs. 2-4).