Chronic Surgical Site Infection Due to Suture-Associated Polymicrobial Biofilm

Background: Surgical site infection (SSI) is a common surgical complication; culture-negative SSI presents a particular problem in management. Methods: Examination of explanted foreign bodies (sutures) using confocal laser scanning microscopy (CLSM) and fluorescent in situ hybridization (FISH) after surgical exploration of a chronic culture-negative SSI. Results: Confocal microscopy (CM) demonstrated bacilli and cocci attached to the surface of the explanted sutures in a mixed biofilm. Florescent in situ hybridization confirmed that Staphylococci were components of the mixed biofilm. Removal of the foreign bodies (sutures) resolved the chronic infection. Conclusion: Chronic SSI can arise from underlying bacterial biofilms, which can invest implanted foreign bodies and associated soft tissue surfaces.