Effect of blood and mucus on tympanostomy tube biofilm formation.

OBJECTIVES/HYPOTHESIS: Tympanostomy tube (TT) biofilm formation may lead to refractory otorrhea and occlusion. The aim of this study was to determine whether TT biofilm formation may be promoted by mucus or blood exposure.

STUDY DESIGN

In vitro, controlled.

METHODS

Fluoroplastic TTs were exposed to blood, mucoid effusion, or saline. Half were allowed to dry. TTs were cultured with Pseudomonas aeruginosa. After 4 days, gentamicin was added to kill planktonic bacteria. Biofilm formation was assessed by quantitative bacterial counts and scanning electron microscopy.

RESULTS

Mucus pretreatment (dry and wet) did not increase biofilm formation. Both dry and wet blood exposure increased biofilm formation by bacterial counts (P < .0001). Biofilm formation was demonstrated by electron microscopy in all groups.

CONCLUSIONS

P. aeruginosa biofilm formation on fluoroplastic TTs is enhanced by blood exposure. Care should be taken to minimize bleeding with TT placement to reduce the risk of biofilm formation.