Figure 4.

Biofilm formation within Mountop and SteriPEN water bottles contribute little to total CFU. (A) Four regions of each water bottle system were sampled with sterile synthetic swabs to quantify biofilm-associated CFU: the interior surface of the bottle cap (1), a 4-cm² region at the air–liquid interface (2), a 4-cm² region completely submerged in inoculum (3), and a 4-cm² region of the interior bottom surface of the bottle (4). Mountop (B,C) and SteriPEN (D,E) systems were inoculated with MycoCocktail and an aliquot of the Day 0 suspension was plated for CFU. Bottles were then allowed to incubate undisturbed at room temperature for 7 days. At Day 7, an aliquot of the suspension was plated for CFU and biofilms within each system were sampled. Biofilm swabs were then plated for CFU and the CFU/cm² in each area was applied to each bottle's total surface area. Biofilm CFU was calculated as a percentage of the initial Day 0 suspension. (B,D) CFU of each region sampled for biofilm-associated CFU. (C,E) CFU of suspensions at Day 0 and Day 7 are compared to that of the biofilm at day 7. n = 2 independent experiments.