SEM Image of Candida Albicans Biofilms on Plastic Coupons

Clinical Image

Candida is a genus of human fungal opportunistic pathogens implicated in localized infections of the oral mucosa, and oral colonization has been associated with pneumonia [1] and sepsis [2]. Candida is the fourth leading cause of nosocomial bloodstream infections in hospitalized patients [3]. Approximately 80% of infections are associated with biofilm formation, and Candida in biofilms demonstrate increased resistance to antifungal therapies [4,5].

Fungal biofilms were prepared on custom-made, pre-sterilized coupons. An inoculum of Candida albicans was transferred onto the coupons and incubated for 1.5 h at 37oC with agitation. After the adhesion phase, the coupons were washed twice, fresh YNB medium added, and further incubated for 24 h at 37oC. Thereafter, the coupons were washed twice and placed in 1% osmium tetroxide for 1 h. Samples were subsequently washed with distilled water, dehydrated in a series of ethanol solutions (70% for 10 min, 95% for 10 min and 100% for 20 min), and air-dried overnight in a desiccator prior to sputter coating with gold (JFC1 100; JEOL). The surface topographies of the C. albicans biofilms were viewed with a scanning electron microscope (Philip XL30CP).

Figure 1 :