Anti-biofilm effect of nanometer scale silver (NmSAg) coatings on glass and polystyrene surfaces against P. mirabilis, C. glabrata and C. tropicalis strains.

Purpose: Nowadays, in order to terminate biofilm associated infections, coating of particular biomaterial surfaces with particular substances, via some nanotechnological tools, is being applied. Therefore, in the present study, investigation of anti-biofilm effects of nanometer scale silver (NmSAg) coatings on glass and polystyrene surfaces against clinical strains of Proteus mirabilis, Candida glabrata and Candida tropicalis was aimed.

Methods: In this study, glass and polystyrene slabs with 1.5 cm × 1.5 cm × 0.3 mm dimensions were cleaned by using surface plasma technology, covered with NmSAg by using a physical vapor deposition machine, and biofilm inhibition was determined by crystal violet binding assay.

Results: According to our results, 32 nm of silver layer on a glass slab decreased biofilm formation of P. mirabilis strain to a maximum amount of 88.1% and caused 20.9% inhibition in biofilm formation of C. glabrata strain. On the other hand, NmS coating of Ag on a polystyrene slab caused 34.4% and 20% inhibitions, respectively, in biofilm formations of C. glabrata and C. tropicalis strains. Although biofilm inhibition of NmSAg layer on polystyrene slab was more (34.4%) than biofilm inhibition caused by NmSAg layer on glass slab (20.9%), C. glabrata strain's biofilm formation on uncoated glass slab was lower than both uncoated and NmSAg-coated polystyrene slabs.

Conclusions: Our results show that glass surfaces with NmSAg coatings can be used as a new surface material of various indwelling devices on which P. mirabilis colonizations frequently occur and in order to avoid C. glabrata-associated biofilm infections, it is more useful to choose a surface material of glass rather than choosing a surface material of polystyrene.