Bacterial biofilm formation on Cochlear implants – a comparative analysis of the bacterial microenvironment of implant and speech processor

Introduction The formation of bacterial biofilm on cochlear implants can lead to refractory infections. Little is known about its specific morphology on cochlear implants. In this study, bacterial biofilm on both implant and speech processor was quantified and visualized by scanning electron microscopy.

Materials and Methods Four primary bacterial strains were tested on implant and speech processor components from three manufacturers: Pseudomonas aeruginosa (ATCC9027), Staphylococcus aureus (ATCC6538), Staphylococcus epidermidis (ATCC12228), and Streptococcus pyogenes (ATCC19615). Biofilm formation of Staphylococcus aureus and Pseudomonas aeruginosa (ATCC9027) was secondarily visualized by scanning electron microscopy. 

Results The highest biofilm formation was observed with S. aureus and P. aeruginosa. Higher biofilm formation was seen on the components of the implant compared to the speech processor. The specific morphology of the bacterial cell surface as well as the extracellular matrix could be visualized by scanning electron microscopy.

Discussion: The present study could demonstrate that the surface characteristics of cochlear implants favor the formation of bacterial biofilm, which can be visualized by scanning electron microscopy. The implant seems to be more susceptible to biofilm formation than the speech processor.

Publication History

Article published online:
24 May 2022