OBJECTIVE

To determine whether biofilm formation on silicone tympanostomy tubes (TTs) is prevented by polyvinylpyrrolidone (PVP) coating.

DESIGN

In vitro microbiologic study.

SUBJECTS

Silicone TTs with and without a PVP coating.

INTERVENTION

The TTs were exposed to blood or phosphate-buffered saline and cultured with Pseudomonas aeruginosa or Staphylococcus aureus. After 4 days, antibiotics were added to kill planktonic bacteria. Biofilm formation was assessed by quantitative bacterial counts and scanning electron microscopy.

RESULTS

Human blood enhanced S aureus biofilm formation on TTs with and without PVP (P < .001). Staphylococcus aureus biofilm formation was similar on TTs with and without PVP coating. Pseudomonas aeruginosa biofilm formation was less on TTs with PVP coating after exposure to phosphate-buffered saline (P = .04), but this difference was not significant after blood exposure (P = .19).

CONCLUSIONS

Polyvinylpyrrolidone coating of TTs imparts resistance to P aeruginosa biofilm formation. The clinical impact of PVP on TTs may be attenuated by exposure to blood, but this will require study in clinical trials.