Virstatin affects bacterial motility and pili production. A&B- Plates of motility of A. baumannii ATCC 17978 strain in presence (B) or absence (A) of virstatin in semi-solid 0.3% TSA after 24 h growth at 37°C. Typical plates are shown. The diameter of the motility zone decreased when medium is supplemented with 100 μM virstatin. The experiments were performed in triplicate. C-F - AFM images of A. baumannii ATCC 17978 water-facing side pellicles after 8 h growth: C&E without virstatin; D&F with 100 μM virstatin. Topographic representation using an uncommon scale made to emphasize the bacterial pili and the ‘EPS’ (extrapolymeric substances) surrounding layer.