Fungi: Are eukaryotic organisms that exist in two forms; yeasts (cells) and moulds (filaments). Examples of fungi include Candida albicans, Cryptococcus newformans, Dermatophytes species.

The term “mycology” is derived from Greek word “mykes” meaning mushroom. Therefore mycology is the study of fungi.

Medical mycology

It is a study of fungi of medical importance

Fungi

Fungi is a group of simple plants that have no chlorophyll, Nucleated, which typically reproduce sexually and asexually, and whose usually filamentous branched somatic are surrounded by cell walls”. So are unicellular, multicellular, or Syncytial (multiple nuclei) spore-producing organisms feeding on organic matter, including molds

Morphological Characteristics

They have at least one nucleus and nuclear membrane

They have endoplasmic reticulum and Mitochondria

They do not have chlorophyll or chloroplast

Cell wall is made of chitin by forming spores

Most fungi are obligate or facultative aerobes.

They are chemotrophic

They secrete enzymes that degrade a wide variety of organic substrates into soluble nutrients which are then passively absorbed or taken into the cell by active transport (saprophytic organism)

There are three basic forms of fungi

Yeasts (cells) for example Cryptococcus neuformans

Moulds (filamentous)

Dimorphic (yeast/filamentous

Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom. The yeast lineage originated hundreds of millions of years ago, and 1,500 species are currently identified

Yeasts are single fungal cells

They reproduce asexually by the process called budding. Examples of yeasts include Cryptococcus neoformans, Candida albicans

Moulds

A mold or mould is a fungus that grows in the form of multicellular filaments called hyphae. In contrast, fungi that can adopt a single-celled growth habit are called yeasts

Are composed of branching cylindrical filaments called hyphae

The mass of intertwined hyphae that accumulates during active growth is a mycelium.(mass of hyphae make up the body of fungi is called mycelium. Plural mycelia)

There are two types of hyphae

Septate their hyphae are separated by cross-walls or septa, typically forming at regular intervals during hyphal growth

Aseptate their hyphae are not separated by cross-walls or septa

Hyphae that penetrate the supporting medium and absorb nutrients are the vegetative or substrate hyphae.

Aerial hyphae project above the surface of the mycelium and usually bear the reproductive structures of the mold, these are called sporangio spores.

is the vegetative part of a fungus or fungus-like bacterial colony, consisting of a mass of branching, thread-like hyphae. The mass of hyphae is sometimes called shiro, especially within the fairy ring fungi. Fungal colonies composed of mycelium are found in and on soil and many other substrates.

Dimorphic fungi are fungi which can exist as mold/hyphal/filamentous form or as yeast. An example is Penicillium marneffei: At room temperature, it grows as a mold. At body temperature, it grows as a yeast

These are fungi that can grow both as yeast and as moulds depending on temperature and

other environmental conditions. Example Histoplasma capsulatum

Fungal species is assigned to a phylum, as well as the appropriate class, order, and family,based on its mode of sexual reproduction, phenotypic properties for example morphology and physiology, and phylogenetic relationships.

Fungi are classified in four phyla

Ascomycota

Zygomycota

Basidiomycota

Chytridiomycota

Is the largest group, which includes more than 60% of the known fungi and about 85% of the human pathogens

Sexual reproduction involves a sac or ascus in which karyogamy (nucleus division) and meiosis occur, producing ascospores

Asexual reproduction is via conidia

Moulds have septate hyphae Examples Blastomyces and Histoplasma, Microsporum and Trichophyton, Coccidioides, and yeast (Saccharomyces and Candida)

Sexual reproduction results in a zygospore

Asexual reproduction occurs via sporangia

Vegetative hyphae are sparsely septate Examples are Rhizopus, Absidia, Mucor, and Pilobolus

Rhizopus is a genus of common saprophytic fungi on plants and specialized parasites on animals. They are found on a wide variety of organic substrates, including “mature fruits and vegetables”, jellies, syrups, leather, bread, peanuts, and tobacco

Absidia is a genus of fungi in the family Cunninghamellaceae. The best-known species is the pathogenic Absidia corymbifera, which causes zygomycosis, especially in the form of mycotic spontaneous abortion in cows

Mucor is a microbial genus of approximately 6 species of moulds commonly found in soil, digestive systems, plant surfaces, rotten vegetable matter and iron oxide residue in the biosorption process.

Sexual reproduction results in four progeny basidiospores supported by a club-shaped basidium

Hyphae have complex septa Examples: Mushrooms, Filobasidiella neoformans, Cryptococcus neoformans

Chytridiomycota is a phylum in the kingdom Fungi. The name is derived from the Greek chytridion, meaning “little pot”, describing the structure containing unreleased zoospores

They are none of medical significanc

Fungi are eukaryotic organisms that exist in two forms; yeasts (cells) and moulds(filaments).

The cell wall of fungi is made of chitin

Fungi are classified into four phyla namely; Ascomycota, Zygomycota, Basidiomycota, Chytridiomycota.

What are fungi?

What is the difference between yeast and mould?

How do you classify fungi