title: Targeting biofilms of multidrug-resistant bacteria with silver oxynitrate.
abstract: A topical antimicrobial, silver oxynitrate (Ag7NO11), has recently become available that exploits the antimicrobial activity of ionic silver but has enhanced activity because highly oxidised silver atoms are stabilised with oxygen in a unique chemical formulation. The objective of this study was to use a multifaceted approach to characterise the spectrum of antimicrobial and antibiofilm activity of a wound dressing coated with Ag7NO11at a concentration of 0.4 mg Ag/cm2. Physiochemical properties that influence efficacy were also evaluated, and Ag7NO11was found to release a high level of Ag ions, including Ag2+and Ag3+, without influencing the pH of the medium. Time-kill analysis demonstrated that a panel of multidrug-resistant pathogens isolated from wound specimens remained susceptible to Ag7NO11over a period of 7 days, even with repeated inoculations of 1 × 106CFU/mL to the dressing. Furthermore, established 72-h-old biofilms of Pseudomonas aeruginosa, Staphylococcus aureus and two carbapenem-resistant Gram-negative bacteria (blaNDM-1-positive Klebsiella pneumoniae and blaVIM-2-positive P. aeruginosa) were disrupted and eradicated by Ag7NO11in vitro. Ag7NO11is a proprietary compound that exploits novel Ag chemistry and can be considered a new class of topical antimicrobial agent. Biocompatibility testing has concluded Ag7NO11to be non-toxic for cytotoxicity, acute systemic toxicity, irritation and sensitisation.
authors.affiliation: Exciton Technologies Inc., Suite 4000, 10230 Jasper Avenue, Edmonton, Alberta T5J 4P6, Canada. Electronic address: lkalan@upenn.edu.
authors.forename: Lindsay R
authors.initials: LR
authors.lastname: Kalan
authors.affiliation: Exciton Technologies Inc., Suite 4000, 10230 Jasper Avenue, Edmonton, Alberta T5J 4P6, Canada.
authors.forename: Deanna M
authors.initials: DM
authors.lastname: Pepin
authors.affiliation: Exciton Technologies Inc., Suite 4000, 10230 Jasper Avenue, Edmonton, Alberta T5J 4P6, Canada.
authors.forename: Imran
authors.initials: I
authors.lastname: Ul-Haq
authors.affiliation: Exciton Technologies Inc., Suite 4000, 10230 Jasper Avenue, Edmonton, Alberta T5J 4P6, Canada.
authors.forename: Steve B
authors.initials: SB
authors.lastname: Miller
authors.affiliation: Exciton Technologies Inc., Suite 4000, 10230 Jasper Avenue, Edmonton, Alberta T5J 4P6, Canada.
authors.forename: Michelle E
authors.initials: ME
authors.lastname: Hay
authors.affiliation: Exciton Technologies Inc., Suite 4000, 10230 Jasper Avenue, Edmonton, Alberta T5J 4P6, Canada.
authors.forename: Roderick J
authors.initials: RJ
authors.lastname: Precht
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects*; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000502:physiology; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000502:physiology; D018030:Silver Compounds / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000502:physiology
chemical_list: D000900:Anti-Bacterial Agents; D018030:Silver Compounds
keywords: Antibiotic resistance; Antimicrobial dressing; Biofilm; Infection; Wound