FIG 4.

Reduction of C. albicans SC5314 surface-associated growth on central venous catheters (CVCs) inserted into rats' jugular veins after treatment with NO-np. Mean fungal burdens in in vitro (A) and in vivo (B) catheters infected with 10⁶ C. albicans cells are shown. The fungal burden in NO-np-treated catheters was significantly lower than that in control catheters. For panel A, each symbol represents 5-mm catheters and the bars show the averages of five catheters. In vitro experiments were performed twice, with similar results obtained each time. For panel B, in vivo experiment was performed once using five animals (average of five 5-mm pieces of catheter per rat) per group. For panels A and B, a concentration of 5 mg/ml of np or NO-np was used. In addition, statistical significance (*, P < 0.05; **, P < 0.001; ns, no significance) was calculated using ANOVA and adjusted by use of the Bonferroni correction. Error bars indicate SDs. (C to F) C. albicans SC5314 strain biofilm formation on catheters placed on the jugular vein of a Sprague-Dawley rat. (C and D) Scanning electron microscopic (SEM) examination of untreated (PBS) C. albicans biofilms; (E and F) SEM examination of C. albicans biofilms treated with 5 mg/ml of NO-np. (C) C. albicans biofilm formed on the luminal surface of the untreated catheter. (D) Higher magnification of the boxed region in panel C. Untreated biofilms showed a network comprising yeast cells (white arrowheads) and hyphae (white arrows) surrounded by large amounts of exopolymeric matrix (black arrows). (E) There was no visible candidal biofilm formation in NO-np-treated catheters. (F) Higher magnification of the boxed region in panel E, with light gray arrowheads indicating fibrous debris. Scale bar for panels C and E, 200 μm; scale bar for panels D and F, 20 μm.