Spions Increase Biofilm Formation by Pseudomonas aeruginosa

Limited research has suggested iron oxide nanoparticles (FeNP) have an inhibitory effect against several different genera of bacteria: Staphylococcus, Bacillus and Pseudomonas spp. In this study researchers looked at the effect of three different sets of Fe...O... nanoparticles (FeNPs) on the development of Pseudomonas aeruginosa PAO1 biofilms. Two of the tested NPs were SPIONs (Superparamagnetic Iron Oxide Nanoparticles). Exposure of cells to the SPIONs at concentrations up to 200 ...g/ml resulted in an increase in biofilm biomass by 16 h under static conditions and a corresponding increase in cell density in the bulk liquid. In contrast, these biofilms had decreased levels of extracellular DNA (eDNA). In contrast, SPION FeNPs incubated with cells were unaffected by exposure to the supermagnet and could not be pelleted. The results of this study indicate a need to reconsider the effects of FeNPs on bacterial growth and biofilm formation and the effect the bacterial cells may have on the use and recovery of SPIONs. (ProQuest: ... denotes formulae/symbols omitted.)