Cryptococcus neoformans is an encapsulated yeastlike fungus that can live in both plants and animals. This species, also known by its teleomorph name, Filobasidiella neoformans, belongs to the broad class of organisms called "club fungi" or Division Basidiomycota, which is one the five major types of fungi. C. neoformans usually grows as a yeast (unicellular) and replicates by budding. Under certain conditions, both in nature and in the laboratory, C. neoformans can grow as a filamentous fungus as pictured here: picture of the organism ^[1]. When grown as a yeast, C. neoformans has a prominent capsule composed mostly of polysaccharides. Microscopically, the India ink stain is used for easy visualization of the capsule. The particles of ink pigment do not enter the capsule that surrounds the spherical yeast cell, resulting in a zone of clearance or "halo" around the cells. The following codes are used with International Statistical Classification of Diseases and Related Health Problems. ... The International Classification of Diseases for Oncology (ICD-O) is a domain specific extension of the International Statistical Classification of Diseases and Related Health Problems for tumor diseases. ... The following is a list of codes for International Statistical Classification of Diseases and Related Health Problems. ... The Mendelian Inheritance in Man project is a database that catalogues all the known diseases with a genetic component, and - when possible - links them to the relevant genes in the human genome. ... MedlinePlus (medlineplus. ... eMedicine is an online clinical medical knowledge base that was founded in 1996. ... The Diseases Database is a free website that provides information about the relationships between medical conditions, symptoms, and medications. ... Divisions Chytridiomycota Deuteromycota Zygomycota Glomeromycota Ascomycota Basidiomycota Fungus growing on a tree in Borneo A fungus (plural fungi) is a eukaryotic organism that digests its food externally and absorbs the nutrient molecules into its cells. ... Divisions Land plants (embryophytes) Non-vascular plants (bryophytes) Marchantiophyta - liverworts Anthocerotophyta - hornworts Bryophyta - mosses Vascular plants (tracheophytes) Lycopodiophyta - clubmosses Equisetophyta - horsetails Pteridophyta - true ferns Psilotophyta - whisk ferns Ophioglossophyta - adderstongues Seed plants (spermatophytes) †Pteridospermatophyta - seed ferns Pinophyta - conifers Cycadophyta - cycads Ginkgophyta - ginkgo Gnetophyta - gnetae Magnoliophyta - flowering plants Adiantum pedatum (a fern... Phyla Porifera (sponges) Ctenophora (comb jellies) Cnidaria (coral, jellyfish, anenomes) Placozoa (trichoplax) Subregnum Bilateria (bilateral symmetry) Acoelomorpha (basal) Orthonectida (parasitic to flatworms, echinoderms, etc. ... Fungi are placed into particular taxa based on reproductive similarities. ... Classes Subdivision Teliomycotina    Urediniomycetes Subdivision Ustilaginomycotina    Ustilaginomycetes Subdivision Hymenomycotina    Homobasidiomycetes - mushrooms The Division Basidiomycota is a large taxon within the Kingdom Fungi that includes those species that produce spores in a club_shaped structure called a basidium. ... Yeasts constitute a group of single-celled (unicellular) fungi, a few species of which are commonly used to leaven bread, ferment alcoholic beverages, and even drive experimental fuel cells. ... General Biological Meaning Budding is a type of asexual reproduction. ... Polysaccharides (sometimes called glycans) are relatively complex carbohydrates. ... Indian ink (or India ink in American English) is a simple black ink once widely used for writing and printing. ...

The species C. neoformans is composed of three variants (v.): C. neoformans v. gattii, v. grubii, and v. neoformans. C. neoformans v. gattii is found mostly in the tropics, but has also been confirmed on southern Vancouver Island on the southwestern coast of Canada. Cryptococcus gattii has recently been shown to be different enough from other subspecies to be elevated to its own species level. C. neoformans v. grubii and v. neoformans have a worldwide distribution and are often found in soil which has been contaminated by bird excrement. The genome sequence of C. neoformans v. neoformans was published in 2005.^[2] The tropics are the geographic region of the Earth centered on the equator and limited in latitude by the two tropics: the Tropic of Cancer in the northern hemisphere and the Tropic of Capricorn in the southern hemisphere. ... Vancouver Island is separated from mainland British Columbia by the Strait of Georgia and the Queen Charlotte Strait, and from Washington State by the Juan De Fuca Strait. ... A coastal image featured on a United States postal stamp. ...

Infection with C. neoformans is termed cryptococcosis. In humans, C. neoformans causes three types of infections: wound or cutaneous cryptococcosis, pulmonary cryptococcosis, and cryptococcal meningitis. Cryptococcal meningitis (infection of the brain) is believed to result from dissemination of the fungus from either an observed or unappreciated pulmonary infection. C. gattii causes infections in immunocompetent people (those having a functioning immune system), but C. neoformans v. grubii, and v. neoformans usually only cause clinically evident infections in persons who have some form of defect in their immune systems (immunocompromised persons). People who have defects in their cell-mediated immunity, for example, people with AIDS, are especially susceptible to disseminated cryptococcosis. Cryptococcal meningitis is often fatal, especially if untreated. This article is about skin in the biological sense. ... The heart and lungs (from an older edition of Grays Anatomy) The lung is an organ belonging to the respiratory system and interfacing to the circulatory system of air-breathing vertebrates. ... Meningitis is inflammation of the membranes (meninges) covering the brain and the spinal cord. ... The immune system is the system of specialised cells and organs that protect an organism from outside biological influences. ... Cell-mediated immunity is an immune response that does not involve antibodies but rather involves the activation of macrophages and NK-cells, the production of antigen-specific cytotoxic T-lymphocytes, and the release of various cytokines in response to an antigen. ... Acquired immunodeficiency syndrome, or acquired immune deficiency syndrome (or acronym AIDS or Aids), is a collection of symptoms and infections resulting from the specific damage to the immune system caused by infection with the human immunodeficiency virus (HIV). ...

During infection, the fungus produces copious amounts of capsule which is sloughed from the yeast and can be detected in the blood or cerebrospinal fluid (CSF). Detection of capsular material, also called cryptococcal antigen, in bodily fluids is the most common way that a diagnosis of cryptococcosis is made. Red blood cells (erythrocytes) are present in the blood and help carry oxygen to the rest of the cells in the body Blood is a circulating tissue composed of fluid plasma and cells (red blood cells, white blood cells, platelets). ... Cerebrospinal fluid (CSF) is a clear bodily fluid that occupies the subarachnoid space in the brain (the space between the skull and the cerebral cortex—more specifically, between the arachnoid and pia layers of the meninges). ... Diagnosis (from the Greek words dia = by and gnosis = knowledge) is the process of identifying a disease by its signs, symptoms and results of various diagnostic procedures. ...

The prevalence of cryptococcosis, has been increasing over the past 20 years because of the onset of AIDS and the expanded use of immunosuppressive drugs. Worldwide, about 5% of people with HIV develop cryptococcosis. Cryptococcosis is also more likely in smokers and in people working outdoors.

Reference

1. ^  Photomicrograph hosted by the Tree of Life project and specifically contributed by the Duke University Mycology Research Unit; the picture is part of the Hymenomycetes article. Retrieved 2005-03-15.
2. ^  Loftus BJ et al. The genome of the basidiomycetous yeast and human pathogen Cryptococcus neoformans. Science 307(5713), 1321-1324. PMID 15653466.
3. Casadevall A, Perfect JR, Cryptococcus neoformans, ASM Press, Washington, DC, 1998.