Figure 5

Biofilm formation and PNAG production. Biofilm formation and PNAG production by statically grown bacteria, in TSB for 24 hours at 37 °C. (A) Data shown represent the normalized crystal violet - biofilm results (OD 590 nm) divided by the individual bacterial growth identified at an optical density of 600 nm. (B) Data shown are the results of bacterial PNAG bound to wheat germ agglutinin horseradish peroxidase conjugate (OD 490 nm). (A,B) Both graphs show the results as the mean ± SEM of three independent experiments, each performed as six technical replicates; An unpaired Students t test was used to compare between two strains (PNAG).Two-tailed non parametric Mann-Whitney U test. (*P < 0.05; **P < 0.01; ***P < 0.001). IN, initial isolate; HA, host-adapted isolate; V₈, the first isolate collected showing a SigB-deficient variant (isolate 15 after week 6).