New research from scientists at the University of Technology Sydney (UTS) demonstrates long-term nanosilver treatment can increase the risk of recurrent infections of antibiotic-resistant pathogenic strains that form biofilms. The scientists show nanosilver kills 99.99% P. aeruginosa in a sample population but the 0.01% cells that persist resume normal growth once the nanoparticle treatment is stopped. The authors caution, since bacteria can adapt to nanoparticles effective regulations of the use of nanoparticles must be implemented, and the use of alternative microbials such as nanosilver should be preserved to fight untreatable infections, with growing antibiotic resistance.