Nitric oxide‐mediated dispersal in single‐ and multi‐species biofilms of clinically and industrially relevant microorganisms

Abstract

SummaryStrategies to induce biofilm dispersal are of interest due to their potential to prevent biofilm formation and biofilm‐related infections. Nitric oxide (NO), an important messenger molecule in biological systems, was previously identified as a signal for dispersal in biofilms of the model organism Pseudomonas aeruginosa. In the present study, the use of NO as an anti‐biofilm agent more broadly was assessed. Various NO donors, at concentrations estimated to generate NO levels in the picomolar and low nanomolar range, were tested on single‐species biofilms of relevant microorganisms and on multi‐species biofilms from water distribution and treatment systems. Nitric oxide‐induced dispersal was observed in all biofilms assessed, and the average reduction of total biofilm surface was 63%. Moreover, biofilms exposed to low doses of NO were more susceptible to antimicrobial treatments than untreated biofilms. For example, the efficacy of conventional chlorine treatments at removing multi‐species biofilms from water systems was increased by 20‐fold in biofilms treated with NO compared with untreated biofilms. These data suggest that combined treatments with NO may allow for novel and improved strategies to control biofilms and have widespread applications in many environmental, industrial and clinical settings.

Resilience of the Oral Microbiota in Health: Mechanisms That Prevent Dysbiosis

“…Nitric oxide is also a signaling molecule that triggers dispersal of various types of bacterial cells from biofilms (Barraud 2009;Schlag 2007). Salivary nitrate concentrations could generate nitric oxide concentrations that decrease biofilm formation by susceptible species (Schlag 2007), which could provide resistance to, and recovery from, plaque accumulation.…”

Improvement of Drinking Water (Surface and Ground) Quality Beneficial to Human Use

“…Sewage system projects are implemented in all towns and villages. Potential pretreatment strategies include inactivation by advanced oxidation, such as UV, with the addition of bio-film signaling agents that either disperse or interfere with quorum sensing [12]. In water treatment, the contaminants are typically pathogens, colloids, non organic materials, and in some cases, trace organic compounds (natural and synthetic).…”

Living biofouling-resistant membranes as a model for the beneficial use of engineered biofilms

“…NO induces biofilm dispersal by enhancing the activity of phosphodiesterases, resulting in the degradation of c-di-GMP (32). NO is effective in dispersing a variety of different biofilms (26), including P. aeruginosa biofilms (32), and NO synthase (NOS) from Bacillus anthracis is active in Escherichia coli (33). Also, sphingomonad biofilms should be dispersed by NO, because strains such as S. wittichii contain 40 diguanylate cyclases and phosphodiesterases (34).…”

“…Dispersal may be triggered by changes in the environment including nutrient levels, oxygen, pH, and temperature and occurs under favorable and unfavorable conditions to expand the bacterial cellular population (24). Upon these changes in the environment, dispersal is regulated via QS cues such as acylhomoserine lactones and 2-heptyl-3-hydroxy-4-quinolone (24) and by fatty acid signals such as cis-2-decenoic acid (25), nitric oxide (NO) (26), and cyclic diguanylate (c-di-GMP) (27). As biofilms disperse, cells degrade Significance Biofouling is a significant problem for membrane-based systems because it reduces flow and increases energy consumption.…”