Candida albicans is a dimorphic organism, a common commensal of oral cavity. It exists harmlessly in oral cavity, GIT, nose and many other sites of the body. In some situations it changes its nature and transforms into pathogens capable of causing infections. Why these transformations occur? Is it due to a change in micro-environment or due to a change in organism itself?
The change is very frequently due to environmental, immune status and nutritional factors, all of which influence one another.
Candida albicans is often harmless, kept in balance with other members of the local microbiota, However, many factors can change the status of C.albicans from harmless microorganism to serious pathogen, such factors are:-
-alteration in host-microbiota due to prolong uptake of antibiotics.
-Changes in host immune response during stress, infection by another pathogen, or immunosuppressant therapy.
-Variation in the local environment such as a shift in pH or nutrition content.
Best Regard
Besides the above mentioned host- factors (e.g. immunosuppression, or change in resident microbiota due to antiobiotic intake) different strains of Candida albicans (organism itself) can differ in their behaviour and pathogenicity. If you are interested have a look at this paper: Article The intraspecies diversity of C. albicans triggers qualitati...
It may be due to changes in environmental factors or immune/nutritional system as suggested by Maurice Ekpenyong .