FIG. 3.
A FISH examination of suture and associated reactive tissue from two patients. Specimens were stained with either 1) the general 16S rRNA probe Eub388, or 2) the nucleic acid stain propidium iodide and either the Staphylococcus genus probe (Sta) or the S. aureus specific probe (Sau). A) A1 shows clusters of cocci (white arrow) and the nuclei of host cells (red arrow). A2 shows that the bacteria were staphylococci (green). A3 shows an overlay of the previous panels, and A4 is a plan view and saggital sections through the staphylococcal biofilm cluster attached to fibrous tissue in this patient. In this last image, cytoskeletal elements of host cells were also visualized by staining f-actin blue with phalloidin. B–D) Specimens from a second patient stained for S. aureus (Sau). B1 shows the surface of reactive tissue visualized by reflected light. B2 shows the Eub388 eubacterial probe specifically staining bacteria in a biofilm cell cluster green (white arrow). B3 shows that the biofilm cluster was composed of S. aureus (in this case red). B4 is an overlay; the mixed red and green signals from the doubly-stained organisms appear yellow. C) S. aureus biofilm clusters adherent directly to the braids of a suture. C1 is a reflected image showing the suture braids (blue arrow) and some of the associated host cells (red arrow). C2 shows four clusters of biofilm stained with Eub388 (green). C3 shows that they were S. aureus (red). Inset shows a high magnification image of one cluster of cocci attached directly to the suture. C4 is an overlay. D) Evidence that the infection in this patient was polymicrobial. D1 is imaged using reflected light, showing suture braids and host cells. D2 shows a cluster of biofilm stained with the Eub388 probe (white arrow). However, the same cluster fails to stain with the Sau probe (D3), demonstrating that in addition to S. aureus the patient was infected with another species of bacteria. D4 is an overlay. Color images available online at www.liebertpub.com/sur