Fig. 3.

Biofilm formation of L. pneumophila ∆lqs, ∆flaA and ∆icmT mutant strains. Biofilms were initiated with exponential phase L. pneumophila JR32, ∆lvbR, ∆lqsR, ∆lqsA, ∆flaA or ∆icmT mutant strains harbouring pNT28 (constitutive production of GFP) in AYE medium within ibiTreat microscopy dishes. Biofilms were grown at 25°C without mechanical disturbance, and confocal microscopy images of biofilm architecture were acquired at 4 μm above the dish bottom after 1, 2, 3 and 6 days of growth. The images shown are representative of three independent experiments. Scale bars, 30 μm.