Methods for removing bacterial biofilms: in vitro study using clinical chronic rhinosinusitis specimens

Am J Rhinol. 2007 Sep-Oct;21(5):527-32. doi: 10.2500/ajr.2007.21.3069.


Background: Bacterial biofilms may be involved in refractory chronic rhinosinusitis (CRS). In vitro, we studied methods for removing biofilms formed by Staphylococcus aureus and Pseudomonas aeruginosa.

Methods: Bacterial isolates were obtained from patients with refractory CRS and were plated and treated with either static administration of citric acid/zwitterionic surfactant (CAZS), saline delivered with hydrodynamic force, or CAZS delivered hydrodynamically. Results were assessed by counting colony-forming units (CFUs) and by confocal scanning laser microscopy (CSLM).

Results: All treatments produced significant reductions in CFU counts (p >or= 0.002). Hydrodynamic CAZS provided the greatest reduction, decreasing CFU counts from control values by 3.9 +/- 0.3 logs and 5.2 +/- 0.5 logs for S. aureus and P. aeruginosa, respectively (99.9% reduction; p = 0.001). CSLM showed decreases in biofilm coverage.

Conclusion: Hydrodynamic delivery of a soap-like surfactant and a calcium-ion sequestering agent may disrupt biofilms associated with CRS. Our results may be relevant to a new approach to refractory CRS.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biofilms*
  • Citric Acid / chemistry
  • Drug Delivery Systems
  • Endoscopy
  • Equipment Design
  • Humans
  • Microbiology*
  • Microscopy, Confocal
  • Pseudomonas aeruginosa / metabolism*
  • Rhinitis / microbiology*
  • Sinusitis / microbiology*
  • Staphylococcus aureus / metabolism*
  • Surface-Active Agents / administration & dosage


  • Surface-Active Agents
  • Citric Acid