Figure 1.

Ft LVS blue–gray colony and bacterial morphology. (A) Mixed cultures of Ft LVS and phase variant (Ft LVSG) viewed on the surface of a Choc II agar plate. Note that Ft LVSG forms smaller colonies that Ft LVS. (B) Blue (LVS) and Gray (LVSG) colonies viewed under a compound light microscope by oblique lighting. The smaller colonies appeared gray. (C) Transmission electron microscopy of Ft LVS and Ft LVSG. While the bacterial dimensions were similar between these two strains from measuring >50 fields, the Ft LVSG strain formed a large amount of membrane vesicles.