Candida albicans Commensalism in Non-human Mammals
The yeast Candida albicans is a human commensal found in the gastrointestinal tract, however, its prevalence as a commensal in other species of mammal is not well understood. In order to address this question of whether C. albicans is living as a commensal or simply passing through other mammal species on the food items they consumed, scat samples were collected from a variety of mammals around the Itasca Biological Station and Laboratories on Lake Itasca, MN. Yeast were routinely isolated from these scat samples, and we identified strains of C. albicans, Saccharomyces cerevisiae, and several previously undescribed yeast. They were subjected to several stressful environmental conditions that would simulate the interior of a mammal, these being high temperatures to simulate the body temperature of mammals, variable pH to simulate primarily stomach and intestinal conditions, and exposure to various concentrations of H2O2 to simulate oxidative stress. Two soil isolates and a C. albicans human blood isolate were also subjected to these same conditions. Those that did closely align with C. albicans showed signs of adaptation towards the conditions similar to that which can be found within the body of many mammals. This indicates that C. albicans, and possibly other closely related species of yeast, may be inhabiting many other mammal species as commensals.