Identification of bacteria in patient biopsies visualized by bacterial viability staining including a 3D reconstruction discriminating viable (green) and dead (red) bacteria (A) (original magnification, ×40). (B) A 3D reconstruction of immunostained biofilm- and non–biofilm-associated patient biopsies with GAS-specific antibody, wheat germ agglutinin (WGA), and Nile red (original magnification, ×63). Arrows indicate multilayered bacterial aggregations. (C) Representative scanning electron micrographs of GAS biofilm and nonbiofilm single-cocci areas in patient biopsies. The boxed area (i) is shown in larger magnification (×10,000) to visualize the biofilm community.