OBJECTIVE: Candida albicans has been a common isolate in posttreatment disease, usually as a monoinfection of the root filled canal. A factor likely to contribute to its pathogenic potential in posttreatment infection is an ability to endure starvation and use serum as a nutritional source. This study evaluated the starvation-survival behavior, growth, and recovery in human serum of C. albicans and compared it with Enterococcus faecalis. STUDY DESIGN: Varying cell densities of C. albicans and E. faecalis were suspended in 5% human serum or water for 4-6 months. Starvation recovery was assessed by addition of 50% serum to starved cells. Cell survival was monitored by periodic removal of aliquots and viable counts. RESULTS: Initial cell density was important for starvation survival. Candida albicans and E. faecalis survived starvation in water for 6 months when the starting cell density was >10(5) and >or=10(8) colony-forming units (cfu)/mL, respectively. Both species thrived in 5% serum from low initial densities (>10(2) and >10(4) cfu/mL for C. albicans and E. faecalis, respectively), and starvation-state cells recovered on addition of 50% serum. CONCLUSION: Candida albicans is well suited for survival in nutrient-limited conditions and can use serum as a source of nutrition and for recovery from starvation. These findings parallel the behavior of E. faecalis, which possesses a similar capacity for starvation survival and growth in serum, traits that are of likely importance for their participation in posttreatment infection. Copyright (c) 2010 Mosby, Inc. All rights reserved.
OBJECTIVE:Candida albicans has been a common isolate in posttreatment disease, usually as a monoinfection of the root filled canal. A factor likely to contribute to its pathogenic potential in posttreatment infection is an ability to endure starvation and use serum as a nutritional source. This study evaluated the starvation-survival behavior, growth, and recovery in human serum of C. albicans and compared it with Enterococcus faecalis. STUDY DESIGN: Varying cell densities of C. albicans and E. faecalis were suspended in 5% human serum or water for 4-6 months. Starvation recovery was assessed by addition of 50% serum to starved cells. Cell survival was monitored by periodic removal of aliquots and viable counts. RESULTS: Initial cell density was important for starvation survival. Candida albicans and E. faecalis survived starvation in water for 6 months when the starting cell density was >10(5) and >or=10(8) colony-forming units (cfu)/mL, respectively. Both species thrived in 5% serum from low initial densities (>10(2) and >10(4) cfu/mL for C. albicans and E. faecalis, respectively), and starvation-state cells recovered on addition of 50% serum. CONCLUSION:Candida albicans is well suited for survival in nutrient-limited conditions and can use serum as a source of nutrition and for recovery from starvation. These findings parallel the behavior of E. faecalis, which possesses a similar capacity for starvation survival and growth in serum, traits that are of likely importance for their participation in posttreatment infection. Copyright (c) 2010 Mosby, Inc. All rights reserved.