Fungi

A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds. These organisms are classified as kingdom Fungi, separate from plants, animals, and bacteria. Fungi have a worldwide distribution and cangrow in a wide range of habitats, including extreme environments such as deserts or areas with high salt concentrations or ionizing radiation, as well as in deep sea sediments. Most fungi are inconspicuous because of the small size of their structures and their cryptic lifestyles in soil, on dead matter, and as symbionts of plants, animals, or other fungi. Fungi perform an essential role in the decomposition of organic matter and have fundamental roles in nutrient cycling and exchange. Many fungal species produce bioactive compounds called mycotoxins, such as alkaloids and polyketides that are toxic to animals including humans, contributing to pathogenecity and disease.

The study of pathogenic fungi is referred to as a medical mycology. There are various examples of pathogenic fungi including but not limited too: Candida species, Aspergillosis, Cryptococcus, Histoplasma, Pneumocystis and Stachybotrys.

Candida species are commonly known to cause opportunist infections in immunocompromised hosts. The immunocompromised hosts that commonly become infected with Candida include transplant patients, cancer patients and AIDS sufferers. Candida infections are difficult to treat and can result in systemic infections leading to death.