Description of Environmental Stress Mediators in Candida Species.

Abstract

The successful spread of the genus Candida micromycetes in various host niches is accounted for by their ability to avoid stress caused by host immune system and other factors aimed at blocking fungal vital processes. The article studies the Transcriptional activator of CDR and the Multidrug resistance regulator controlling overexpression of target genes supposed to ensure resistant properties in genus Candida species against fluconazole. An environmental stress mediator is a term that characterizes a pleiotropic transcription factor as a structure capable of sensing an effect influence of a single environmental factor and transforming it into a process of increasing drug resistance in Candida micromycetes by promoting membrane-bound transporter activity. Gene point mutations or copy number alterations also increase fungal adaptive potential to fluconazole, which may further provide a selective populational advantage. The article schematically outlines a mechanism for developing adaptive response against genus Candida fungi involving environmental stress mediators to antimycotic fluconazole based on efflux proteins ATP-binding cassette and Major-Facilitator superfamily. Such premises describing activity of transcription activators mediating environmental stress suggest that a single transcription factor can upregulate expression of several genes; a single gene can be activated by several transcription factors; activation of the transcription factors described here is triggered by oxidative and osmotic stress; combination stress can block the functioning of environmental stress mediators. Knowing the genetic background of pathogenic strains may allow for simulating a combination stress able to negatively impact on micromycete life cycle.