Biofilm formation by Pseudomonas aeruginosa on ossicular reconstruction prostheses.

PURPOSE: Ossicular chain reconstruction may be complicated by prosthesis extrusion. As prostheses are commonly placed in middle ears contaminated with biofilm-forming bacteria, such as Pseudomonas aeruginosa (PA), extrusion may be caused by development of a biofilm on the prosthesis and the host response to this biofilm. The purpose of this experiment was to determine if PA forms biofilm on different ossicular chain reconstruction prostheses to a different degree.

METHODS

Prostheses made of titanium, hydroxylapatite (HA), and plastic (23 each) were cultured with PA in broth for 96 hours. Biofilm formation was assessed by electron microscopy and quantitative microbiology.

RESULTS

Titanium prostheses formed less biofilm than plastic (P = .0003) and HA (P = .003), but there was no difference between HA and plastic. Correction for surface area did not alter these significant differences.

CONCLUSIONS

Pseudomonas aeruginosa forms biofilm on ossicular prostheses, particularly those made of plastic and HA. These differences could, in part, explain the extrusion propensity of certain biomaterials.