Candida colonization of silicone voice prostheses: Evaluation of device lifespan in laryngectomized patients

BACKGROUND: Purpose of this study was to investigate biofilm formation by yeasts on silicone-rubber voice prostheses in order to evaluate the life-time compared to the species isolated and to the number of organisms grown. Furthermore, Candida albicans germ tube antibody (CAGTA) was detected for discriminating between possible infection and colonization. METHODS: Over a 5-year period, a laryngectomized group of 28 patients were included in the study and a total of 134 prostheses were subjected to microbial analysis. A CAGTA detection assay was performed too. RESULTS: Mean prostheses lifespan was 215 days. All voice prostheses were colonized by yeasts, more often with two yeast species. No significant correlation (P=0.081) was seen between the number of yeast species isolated and prosthesis lifespan. The most frequently found yeast species on voice prostheses was C. albicans. Significant correlation (P<0.001) was seen between yeasts grown (CFU/mL) on prosthesis and the life-time. While, no significant correlation (P=0.054) was seen between the number of yeast species isolated and number of CFU/mL grown. The CAGTA titers observed, ranged from <1/20 to 1/320 and only two with positive results. CONCLUSIONS: This study underline the importance of the leakage of fluids as the main reason for valve insufficiency caused by biofilm formation, a short clinical life-times of voice prostheses not correlated with simultaneous presence of more than one species of yeast but linked to certain biofilm composition. Finally, the CAGTA detection assay is a reliable marker for discriminating between candidiasis infection and colonization.