Figure 2

“Comets” of S. aureus cells form in front of dendrites.

Dendrites were observed using phase contrast microscopy (A). After 15 h growth, phase bright aggregates (indicated with an arrow) occurred at the tip of the dendrites (Newman strain shown) Scale bar = 100 μm; (B) After 8–12 h of incubation in all the strains that produced dendrites, dendrites were preceded by ‘comets’ of cells, a phase bright aggregate that had a trail of cells behind it leading back to the central colony (at ×100 magnification). Only RN6390B did not produce comets. All images are at the same scale, Scale bar = 100 μm; (C) The Newman strain comet head at ×400 magnification on a 10 ml plate. The image shows that the phase bright comet cores are composed of a grouping of cells, Scale bar = 20 μm. All presented images are representative of 3 independent biological replicates.