Composition and architecture of biofilms on used voice prostheses.

BACKGROUND Biofilms on medical devices are a frequent reason for failure of the device. Voice prostheses in laryngectomized patients deteriorate within 3 to 4 months due to adhering biofilms, impeding proper functioning. Recently, we showed that these biofilms are dominated by Candida and lactobacilli. However, the early report of this finding lacked an in depth analysis of the species diversity and community structure. METHODS Denaturing gradient gel electrophoresis (DGGE) and sequence analysis of amplified rRNA genes was used to identify microorganisms. Fluorescence in situ hybridization (FISH) was used to analyze biofilm architecture. RESULTS Candida are the predominant fungi in the biofilms, while lactobacilli are the predominant bacteria in all investigated biofilms, followed by streptococci. FISH shows that lactobacilli and streptococci seem to have an important interaction with fungi. CONCLUSION The results give a better understanding of biofilm formation and can be used in further development to prevent biofilm formation on voice prostheses.