Antimicrobial and antibiofilm activity and biological decontamination efficiency of ED-1 emulsion

Abstract

Antimicrobial and antibiofilm activity as well as biological decontamination potential of emulsion ED-1, highly efficient in radiological decontamination of metal surfaces contaminated with uranium isotopes, was assessed. The antimicrobial potency of ED-1 was evaluated against 10 different microorganisms including four Gram-negative bacteria (Acinetobacter baumannii ATCC 19606, Escherichia coli NCTC 9001, Klebsiella pneumoniae ATCC 13803, Pseudomonas aeruginosa NCTC 10662), four Gram-positive bacteria (Enterococcus faecalis ATCC 29212, Enterococcus faecium ATCC 6057, Listeria monocytogenes NCTC 11994, Staphylococcus aureus NCTC 6571) and two fungi (Candida albicans ATCC 10231 and Candida parapsilosis ATCC 22019). Although without strong bactericidal and fungicidal properties in standard agar diffusion assays, ED-1 effectively inhibited the growth of P. aeruginosa cells in liquid culture and more importantly, showed high potency to disperse P. aeruginosa biofilms. ED-1 was also capable to efficiently remove Bacillus subtilis ATCC6633 spores in quantitative and a semi-quantitative biological decontamination tests on metal surfaces. Antimicrobial and antibiofilm activity and biological decontamination efficiency of ED-1 was comparable and better to that of calcium hypochlorite solution or commercial decontaminant BX-24. This study highlighted the possibility to use ED-1, with up to 5-fold reduced amounts of calcium hypochlorite in comparison to currently used methodology, for both biological and radiological decontamination, resulting in both environmental and financial benefits.