FIG 5.

Cellular ultrastructure reveals changes to membrane integrity. Transmission electron micrographs were used to examine the effect of 10-nm AgNPs on P. aeruginosa biofilms. (A to D) Negatively stained transmission electron micrographs of P. aeruginosa PAO1 biofilms cultured in silicone tubing for 72 h and either left untreated (A) or treated for 18 h with tobramycin (94.0 μg/ml) (B), 10-nm AgNPs (0.312 μg/ml) (C), or 10-nm AgNPs (0.312 μg/ml) plus tobramycin (94.0 μg/ml) (D). Asterisks in panel D highlight cells with increased cytoplasmic clearing and morphological changes compared to untreated cells in panel A. Bar, 50 nm.