RESUMO
Once sutures become contaminated it is difficult for local tissue defenses or antibiotics to eliminate the bacteria and prevent infection. Impregnation of sutures with antibiotics before implantation is one way to prevent bacterial seeding of the suture surface. In this study, braided silk and Dacron sutures were impregnated with the antibiotic complex, neomycin palmitate. Using our standard wound model in the mouse, the efficacy of these biocidal sutures was determined in the presence of Staphylococcus aureus, Escherichia coli, Proteus mirabilis, and Pseudomonas aeruginosa. Implantation of these biocidal sutures into tissue contaminated with 10(7) organisms resulted in substantially decreased numbers of bacteria as compared with that of tissue receiving control sutures. In most cases, the tissue bacterial counts in the presence of biocidal sutures were also considerably lower than that for similarly contaminated tissue without a suture. Consequently, the presence of the neomycin palmitate eliminated the infection-potentiating effect of the suture. The therapeutic benefit of the biocidal sutures was related to the dose of antibiotic complex and was not adversely affected by delaying suture implantation.