Objective: The purpose of this study was to determine if the recently developed novel antimicrobial/antibiofilm agent Next-Science (NS) inhibits biofilm development by Staphylococcus aureus or Pseudomonas aeruginosa on tympanostomy tubes (TT) and to define the concentration of NS at which this inhibition occurs.
Methods: Preliminary titration experiments determined the effective concentrations of NS that completely inhibit the planktonic growth of S. aureus and P. aeruginosa. Since NS has the potential to inhibit both planktonic growth and biofilm development, we examined the antibiofilm effect using the established concentrations that inhibited planktonic growth. Biofilms developed on TT using the microtiter plate assay were assessed quantitatively by determining the number of microorganisms per tube (CFU/tube) and qualitatively by visualization with confocal laser scanning microscopy (CLSM).
Results: Planktonic growth of S. aureus and P. aeruginosa was inhibited by 20.3 μg/mL and 325 μg/mL of NS, respectively. While S. aureus and P. aeruginosa formed well-developed biofilms on TT at 24 h without treatment, addition of the indicated concentrations of NS at the time of inoculation of the TT inhibited the formation of biofilms by both organisms. CLSM confirmed the absence of biofilms on either the inner or outer surface of the treated TTs. At 8 h post-inoculation, P. aeruginosa formed a partial biofilm on the TT when untreated. In comparison, the NS-treated biofilms failed to develop further and the CFU/TT were significantly reduced.
Conclusion: The novel antimicrobial agent NS inhibited the development of S. aureus and P. aeruginosa biofilms on TTs. The same concentrations of NS inhibited both planktonic growth and biofilm development.
Keywords: Antimicrobial; Biofilm; Otitis media; Pseudomonas aeruginosa; Staphylococcus aureus; Tympanostomy tube.
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