Biofilm formation in cochlear implants with cochlear drug delivery channels in an in vitro model.
BACKGROUND
Cochlear implant (CI) drug delivery (DD) may improve electrophysiological outcomes, but it may also increase the risk of suppurative complications. The aim of this study was to evaluate the development of bacterial biofilms on DD ports when subjected to varying types of penetration.


METHODS
Silastic models were constructed to represent CIs with a DD channel, with an intact port, a widely opened port, a noncoring needle penetrating the port, and a noncoring needle removed from the port. CIs were exposed to a culture of a biofilm-forming strain of Staphylococcus aureus for 5 days. Biofilm formation was assessed with quantitative bacterial counts (after eliminating planktonic bacteria) and scanning electron microscopy.


RESULTS
Bacterial counts were significantly higher in CIs with widely fenestrated ports than all other port conditions (P = 0.0003).


CONCLUSIONS
Biofilm formation may be minimized on CIs with DD by using fine, noncoring needles and limiting the duration of port penetration.
Johnson
Trey A
TA
Department of Otolaryngology, University of Florida, Gainesville, FL 32610-0264, USA.
Loeffler
Kimberly A
KA
Burne
Robert A
RA
Jolly
Claude N
CN
Antonelli
Patrick J
PJ
D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D018441:Biofilms; D003054:Cochlear Implants; D016503:Drug Delivery Systems / Q000295:instrumentation; D004867:Equipment Design; D008855:Microscopy, Electron, Scanning; D008953:Models, Anatomic; D009339:Needles; D013211:Staphylococcus aureus / Q000502:physiology*
D000900:Anti-Bacterial Agents