The effect of aspirin on adherence of slime-producing, coagulase-negative staphylococci to vascular grafts.

In this study, we examined the adherence of slime-producing standard Staphylococcus epidermidis strain ATCC 12228 to Dacron and polytetrafluoroethylene (PTFE) grafts in in vitro medium either containing salicylate or not. Dacron and PTFE graft pieces of standard size were placed in trypticase soy broth either containing 5 mM acetylsalicylic acid solution or not. These soy broths also contained 1 x 10(7) colony-forming units/mL S. epidermidis ATCC 12228. The incubation period lasted for 18 hr at 37 degrees C. The bacteria on the graft were freed by vortexing. The obtained bacteria suspension was diluted serially. Afterward, the suspension was plated on 5% sheep blood agar and counted after overnight incubation. In this study, we demonstrate that aspirin of an ideal concentration (5 mM) decreased the adherence of slime-producing S. epidermidis strain to Dacron and PTFE grafts. The mean number of colonies was significantly lower for both Dacron and PTFE groups in salicylated medium. We believe that aspirin provided in the postoperative period can, by maintaining the ideal serum level, decrease graft infections emerging due to coagulase-negative staphylococcus.