title: Reduced bacterial deposition and attachment by quorum-sensing inhibitor 4-nitro-pyridine-N-oxide: the role of physicochemical effects.
abstract: Surface-attached chemical groups that resist protein adhesion are commonly characterized as being hydrophilic, H-bond acceptors, non-H-bond donors, and electrically neutral. Quorum-sensing (QS) inhibitor 4-nitropyridine-N-oxide (4-NPO) that previously was found to decrease Pseudomonas aeruginosa biofilm formation possesses all of these characteristics, making this molecule an ideal antiadhesive compound. It was hypothesized that once 4-NPO adsorbs to either the solid surface or bacteria, resultant changes in the physical-chemical surface properties of the solid surface and bacteria will reduce the extent of bacterial adhesion. These physical-chemical effects take place prior to the commencement of already well-established QS biofilm-inhibition mechanisms. Bacterial adhesion experiments to silica conducted in quartz crystal microbalance with dissipation (QCM-D) and parallel plate flow cells demonstrated that 4-NPO reduces bacterial adhesion to silica-coated surfaces by the adsorption of 4-NPO to the silica surface as well to the outer membrane of both gram-negative P. aeruginosa PAO1 and gram-positive Staphylococcus aureus. 4-NPO effectively neutralizes both the bacterial and silica surface charge, and it is proposed that this neutralization of local surface charge heterogeneities by 4-NPO adsorption is the mechanism responsible for decelerating rates of bacterial deposition.
authors.affiliation: Zuckerberg Institute for Water Research, Ben-Gurion University of the Negev, Sede Boqer Campus 84990, Israel.
authors.forename: Nune
authors.initials: N
authors.lastname: Vanoyan
authors.forename: Sharon L
authors.initials: SL
authors.lastname: Walker
authors.forename: Osnat
authors.initials: O
authors.lastname: Gillor
authors.forename: Moshe
authors.initials: M
authors.lastname: Herzberg
mesh_terms: D001422:Bacterial Adhesion / Q000187:drug effects*; D018441:Biofilms / Q000187:drug effects; D055598:Chemical Phenomena / Q000187:drug effects*; D003497:Cyclic N-Oxides / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D057927:Hydrophobic and Hydrophilic Interactions; D011550:Pseudomonas aeruginosa / Q000737:chemistry / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D053038:Quorum Sensing / Q000187:drug effects*; D013211:Staphylococcus aureus / Q000737:chemistry / Q000166:cytology / Q000187:drug effects* / Q000502:physiology
chemical_list: D003497:Cyclic N-Oxides; C013620:4-nitropyridine 1-oxide