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.
Highlights
Every natural wet surface is a substrate for microbial biofilms
It can produce a flux of nitric oxide of 30 pmol cm−2 s−1, and this can efficiently reduce the adhesion of Staphylococcus aureus, Staphylococcus epidermidis, and E. coli by 96%, 48%, and 88%, respectively (Charville et al 2008)
In terms of biofilm dispersal, molsidomine was the most potent molecule. It was effective in dislodging biofilms formed by S. enterica sv Typhimurium 14028, the cocktail of the six Salmonella outbreak strains and E. coli O157:H7
Summary
Every natural wet surface is a substrate for microbial biofilms. These sessile multicellular microbial consortia are embedded within the self-produced extracellular polymeric substances (EPS) (Costerton et al 1987; Marvasi et al 2010; Solano et al 2002; Wingender et al 1999). Activity of sodium nitroprusside has been recently characterized in detail It can produce a flux of nitric oxide of 30 pmol cm−2 s−1, and this can efficiently reduce the adhesion of Staphylococcus aureus, Staphylococcus epidermidis, and E. coli by 96%, 48%, and 88%, respectively (Charville et al 2008). It appears that nitric oxide could have a universal effect on the dispersal of bacterial biofilm including both Gram-positive and Gram-negative bacteria (Xiong and Liu 2010)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
