Figure 2.

Schematic drawing of a biofilm-infected bronchial lumen based on ex vivo observation (Figure 1). (A) The bronchial lumen with two non-attached biofilms surrounded by polymorph nuclear leukocyte (PMN) infiltrated mucus; (B) oxygen gradient through the mucus towards the biofilm. High concentration of PMNs results in steeper oxygen gradients due to high consumption; (C) high concentration of PMNs around a biofilm results in slow-growing bacteria within the biofilm. Lesser concentration results in increased growth due to improved accessibility to oxygen; (D) differences in growth rate may result in differentiated tolerance towards antibiotics. Jensen et al. [46].