In mixed species biofilms of other bacteria with Candida species, bacterial association with hyphae predominates association with yeast cells [22, 23]. Hogan et al. evaluated interactions of Pseudomonas aeruginosa and Candida, and found that C646 mouse Pseudomonas aeruginosa had a predilection for the hyphal form without affecting the yeast form of the fungus [22]. In studies of mixed species Thiazovivin datasheet infections of S. aureus and C. albicans, similar to P. aeruginosa, adherence to the Candida hyphae was nearly
30-fold more than adherence to the yeast form of Candida [23]. In our experiments (data not shown) we found adherence of S. epidermidis to both yeasts and hyphae of Candida which may facilitate mixed species biofilms of these two organisms and partly contribute to the increased clinical frequency of mixed species biofilm infections of C. albicans and S. epidermidis. The yeast and hyphal forms of
C. albicans may act as a scaffold on which biofilms of S. epidermidis are formed [23]. Candida infection is associated with tissue invasion by hyphae and it been hypothesized that staphylococcal tissue infection is facilitated by its association with Candida hyphae [23]. Synergistic effects of C. albicans and S. epidermidis have been reported by other investigators [16, 17]. In mixed species biofilms of C. albicans and S. epidermidis, presence Adenosine triphosphate of slime producing strains of S. epidermidis decreases antifungal susceptibility related to decreased buy Everolimus penetration of the fluconazole through the
ECM and conversely the fungal cells protected slime negative S. epidermidis against vancomycin [16]. In an in vitro study of mixed species biofilms of C. albicans and S. epidermidis, enhanced the growth of S. epidermidis was observed [17]. We used a clinically relevant model of subcutaneous catheter biofilm infection to evaluate the clinical implications of mixed species biofilm infection [24]. In mixed species biofilms, catheter biofilm infection of S. epidermidis increased in the presence of C. albicans. Pre-insertion cultures revealed lower catheter infection of S. epidermidis in mixed species infection compared to single species S. epidermidis but on day 8 of insertion in vivo, we found increased catheter infection of S. epidermidis in the mixed species infection. This suggests that mixed species environment facilitates biofilm aggregation and not the initial phase of S. epidermidis adhesion to catheters. Enhanced biofilm aggregation was associated with enhanced dispersal that led to increased systemic dissemination of S. epidermidis in the mixed species infection. Increased virulence and mortality has been described in mouse models of dual infection with C. albicans and S. aureus but not with S. epidermidis[12–14]. Peters et al.