FIG. 2.

Confocal microscopic examination of suture and associated reactive tissue stained with the BacLight Live/Dead kit, showing various aspects of viable bacteria in biofilm configuration (indicated by white arrows). Images shown are representative from five patients. A) Biofilm consisting largely of cocci growing between the suture braids. The upper left panel shows live bacteria (green), and the upper right panel shows dead bacteria (red) and the autofluorescent sutures. The lower left panel is an overlay. B) Cross-section through the braids of a multifilament suture shows that the biofilm bacteria had penetrated the crevice formed by individual braids. The upper left panel is a maximum projection XY “plan” view and saggital sections in the XY and XZ planes are to the right and below respectively. The biofilm was up to 30 microns thick. C) The patient shown in panel B also had clusters of cocci in biofilms attached to the associated reactive tissue that had invested the suture material (blue arrow). The nuclei of host inflammatory cells were also seen (red arrow). D) Clusters of live coccal biofilm attached to the fibrous sheath (the nuclei of host cells are red) which was itself overlying the braids of the sutures (evident as blue striations). E) Extensive coccal biofilm attached to the fibrous sheath investing the suture. Inset is high magnification of a cluster of biofilm cocci. F) Biofilm clusters of live cocci attached to sclerotic fibrous tissue that was in intimate association with the suture. G) Clusters of viable bacteria attached to the suture braids (red). H) In some cases clusters of bacteria (white arrow) were in close vicinity to the sutures (red arrow) but not directly attached. This is consistent with the presence of EPS surrounding the bacterial cluster and attaching it to the suture surface. I) Higher magnification showed that the cluster in panel H was made up of live coccal cells (green) in close proximity to a host cell (red). Some of these bacteria appear to be in the process of division. Color image is available online at www.liebertpub.com/sur