FIG 4.

Impact of phage treatment on crystalline biofilm formation. Models replicating an established infection (10¹⁰ CFU P. mirabilis) were used to evaluate the impact of phage treatment on crystalline biofilm formation. Test models were treated with phage at an MOI of 1:1 phage to bacteria (10¹⁰ PFU to 10¹⁰ CFU) at 45 min after inoculation with P. mirabilis. Both test and control models were deactivated after 10 h, and levels of crystalline biofilm formation were measured on descending sections. (A) Schematic of urethral catheter showing sections subject to analysis in part B. (B) Quantification of crystalline biofilm formation and encrustation on catheter sections (total calcium present on each catheter section examined). Images below the chart provide examples of SEM visualization of catheter cross sections, distal to sections 1 to 3, and levels of encrustation. Bars on SEM images represent 200 μm. (C) pH of urine in residual bladder model media at end of experiments. (D) Enumeration of viable cells in residual urine in bladder models at the end of experiments (no significant differences). All data represent the means from 3 replicate experiments, and error bars show the standard error of the mean. **, P < 0.01; ***, P < 0.001 for control section versus phage-treated model.