RESUMO
The purpose of this study was to determine the presence of individual microorganisms and the most frequent microbial combinations in the biofilm of the indwelling Provox2 voice prosthesis in situ. Furthermore, we wanted to evaluate the possible influence of biofilm composition on the mean and median lifetime of these voice prostheses. Over a 5-year period, implantation of a Provox2 voice prosthesis was performed in 85 patients, or 90% of the overall number of patients who underwent total laryngectomy. In total 100 implanted voice prostheses, at least one of every patient, were microbiologically processed immediately after being replaced. Out of the total of 292 isolates, 67% were bacteria and the remaining 33% were yeasts. The most frequently found yeast species on voice prostheses biofilms was C. albicans, followed by C. krusei and C. tropicalis. The most frequently isolated bacteria included Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Proteus mirabilis, and Streptococcus agalactiae. Simultaneous presence of bacteria and fungi was established in 83% of the processed voice prostheses; in 16% of samples the biofilm contained only one or more bacterial species. The mean time of implantation was 238 days and the median lifetime of the device was 180 days. Dividing the prostheses in four groups according to the composition of biofilm revealed that the device lifetimes varied significantly between groups. The longest lifetime of voice prostheses was associated with the presence of single fungal isolate in combination with bacteria. There is a significant correlation between biofilm composition and the device life time.
