Effects of tigecycline and daptomycin on murine gut colonization by Candida albicans

Adult male Crl:CD1 (ICR) BR mice were fed chow containing Candida albicans or regular chow. Both groups were subsequently given tigecycline or daptomycin or normal saline subcutaneously for 10 days. To determine the effect on the stool yeast concentration, stool cultures were performed immediately before, at the end, and 1 week after discontinuation of treatment. Candida-colonized mice treated with tigecycline or daptomycin had higher counts of the yeast in their stools than control C. albicans-colonized animals treated with saline. Tigecycline caused a significant increase of 2.1 log(10) CFU g(-1) of stools in C. albicans concentration, while daptomycin caused a minor increase of 0.4 log(10) CFU g(-1) of stools. Mice fed regular chow and treated with the study antibiotics or saline did not have any Candida in their stools. Dissemination of Candida was not detected in any animal. These data suggest that tigecycline induces a substantial increase in the intestinal concentration of C. albicans, while daptomycin causes only a minimal increase. However, these increases are not associated with dissemination of the yeast to internal organs. Clinical studies in humans are needed to validate our findings, especially in patients at risk of developing disseminated candidosis.