title: Systematic analysis of the ability of Nitric Oxide donors to dislodge biofilms formed by Salmonella enterica and Escherichia coli O157:H7.
abstract: Biofilms in the industrial environment could be problematic. Encased in extracellular polymeric substances, pathogens within biofilms are significantly more resistant to chlorine and other disinfectants. Recent studies suggest that compounds capable of manipulating nitric oxide-mediated signaling in bacteria could induce dispersal of sessile bacteria and provide a foundation for novel approaches to controlling biofilms formed by some microorganisms. In this work, we compared the ability of five nitric oxide donors (molsidomine, MAHMA NONOate, diethylamine NONOate, diethylamine NONOate diethylammonium salt, spermine NONOate) to dislodge biofilms formed by non-typhoidal Salmonella enterica and pathogenic E. coli on plastic and stainless steel surfaces at different temperatures. All five nitric oxide donors induced significant (35-80%) dispersal of biofilms, however, the degree of dispersal and the optimal dispersal conditions varied. MAHMA NONOate and molsidomine were strong dispersants of the Salmonella biofilms formed on polystyrene. Importantly, molsidomine induced dispersal of up to 50% of the pre-formed Salmonella biofilm at 4°C, suggesting that it could be effective even under refrigerated conditions. Biofilms formed by E. coli O157:H7 were also significantly dispersed. Nitric oxide donor molecules were highly active within 6 hours of application. To better understand mode of action of these compounds, we identified Salmonella genomic region recA-hydN, deletion of which led to an insensitivity to the nitric oxide donors.
authors.affiliation: Soil and Water Science Department, University of Florida-IFAS, Gainesville, FL, USA.
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Marvasi
authors.affiliation: Microbiology and Cell Science Department, University of Florida-IFAS, Gainesville, FL, USA.
authors.forename: Charles
authors.initials: C
authors.lastname: Chen
authors.affiliation: Microbiology and Cell Science Department, University of Florida-IFAS, Gainesville, FL, USA.
authors.forename: Manuel
authors.initials: M
authors.lastname: Carrazana
authors.affiliation: Soil and Water Science Department, University of Florida-IFAS, Gainesville, FL, USA.
authors.forename: Ian A
authors.initials: IA
authors.lastname: Durie
authors.affiliation: Soil and Water Science Department, University of Florida-IFAS, Gainesville, FL, USA ; Cancer and Genetics Research Center, Genetics Institute, 2033 Mowry Road, Gainesville 32611, FL, USA.
authors.forename: Max
authors.initials: M
authors.lastname: Teplitski
keywords: Bacterial signaling; Biofilm control; Food-borne pathogens; Nitric oxide