Biogenic selenium nanoparticles inhibit Staphylococcus aureus adherence on different surfaces

The global issue of nosocomial infection is owing to bacterial colonization and biofilm formation on medical devices which primarily affects critically ill and/or immuno-compromised patients and also leads to malfunctioning of the devices. Therefore, it is desirable to prevent bacterial colonization on these devices by coating with a non toxic antimicrobial agent or bacterial adherence inhibitor. Here we have shown Bacillus licheniformis JS2 derived selenium nanoparticles (SeNPs) inhibit Staphylococcus aureus adherence and micro-colony formation on polystyrene, glass, and catheter surface. Results indicated that, the coating of these non toxic biogenic SeNPs, at a concentration of 0.5 mg Se/ml, prohibits bacterial load to more than 60% on glass and catheter surface, when incubated at 4 degrees C for 24 h in phosphate buffered saline. Furthermore, confocal and electron microscopic observations strongly suggested the inhibition of biofilm and micro-colony formation on SeNP coated glass and catheter surfaces when cultured at 37 degrees C for 72 h in a nutrient rich medium. The study suggests that coating of biogenic SeNPs on medical devices could be an alternative approach for prevention of biofilm related infections. (C) 2015 Elsevier B.V. All rights reserved.