One of the five taxonomic kingdoms(along with Animalia, Plantae,Protista and Monera), the Fungi area diverse group of heterotrophicorganisms with a rigid cell wall.The fungi (singular, fungus ) areeucaryotic spore bearing protiststhat lack chlorophyll.A group of microorganisms thatincludes moulds and yeasts.They are usually found in moist areaor grows in dead decaying ,organicmatter.
FEATURES OF FUNGI Eukaryotic chemoorganotrophic organisms that have no chlorophyll. Non vascular organism. Reproduce by means of spores usually air disseminated. Both sexual (miotic) and asexual (mitotic) spores may be produced depends on species and environment. Typically not motile although few (chytrids)have a motile phase. Like plants fungi have alternation of generation. Vegetative body mainly unicellular(yeast) or composed of microscopic threads called hyphae. Cell wall similar in structure to plants but differ in chemical composition, fungi cell walls are composed of chitin. Plant cell are mainly composed of cellulose. Fungi are heterotrophs, obtaining their nutrients by absorption. Store carbohydrate as glycogen. They are saprophytic ,parasitic organism.
FUNGI MOULD YEAST LIKE FUNGI YEAST DIMORPHIC They grow partly Filamentous and Unicellular They exist in two As yeasts and mycellial Spread rapidly forms, both partly as elongated Form spores and through host body Yeast and spread by spores cells resembling Yeast moulds hyphae(psudomyceOnly locally invasive saccharomyces Taphrina lium) Ring worm fungi Candida albinos
HOW DO WE CLASSIFY ?1.Zygomycota:. Members of the division Zygomycota are known as zygomycetes. Zygomycetes producesexual spores known as zygospores as well as asexual sporangiospores. mold Rhizopus stolonifer2.Ascomycota: These organisms form their sexual spores within a sac called an ascus. Therefore, theyare called sac fungi. yeast Saccharomyces.3. Basidiomycota: After the sexual cells have united, they undergo division and produce a clubshapedstructure called a basidium. Mushrooms4.Deuteromycota: These fungi lack a known sexual cycle of reproduction and are said to be“imperfect.” ringworm.5.Mycophycota (lichens): These fungi depends on algae or cyanobacteria for food.crustose lichens
MOULD VS YEASTPOINT OF MOULD YEASTDISTINCTIONSTRUCTURE Multicellular with tubular , Mostly unicellular and existing filamentous hyphae(branches) individually or with buds growing on them.PREDOMINANCE OF Any organic environment Mostly occur naturally inOCCURRENCE having a moist/humid oceans. atmosphere and not exposed to harsh weather conditionsMETHOD OF Production of sexual or Budding or binary fission.REPRODUCTION asexual , airborne spores.APPEARANCE Threadlike, come in a wide Round or oval-shaped, dull variety of colors and hues. colored and mostly monochromatic.
HOW THEY REPRODUCE?SEXUALLY-Two different cells ,one with ‘+’strain (male) another is ‘-’ strain(female) comes closer and fusetogether. First cytoplasm thennuclei fuse together.ASEXUALLY-Production of various types ofsporesFragmentation – hyphae dry outand shatter releasing individualcells that act like spores.Budding – small offspringA-D-budding ,F -H-fission , shownin the figure.
MYCOSES INFECTIONS CAUSED BY FUNGI SUPERFICIAL MYCOSES -AFFECTS SYSTEMIC MYCOSES-AFFECTS DEEPOUTERMOST LAYERS .e .g ATHLETE’S FOOT, ORGANS. e.g TINEA VERSICOLOR CANDIDIASIS,ASPERGILLOSIS CUTANEOUS MYCOSES –affects DUE TO PRIMARY PATHOGENS- deeper into epidermis,also includes primarily originate from lungs then hair, nail spread to other organ system. SUBCUTANEOUS MYCOSES-affects DUE TO OPPORTUNISTIC subcutaneous tissues,muscle and PATHOGENS-affects those with fascia. immune deficiency
ANTIFUNGAL DRUGSANTIFUNGAL MECHANISM OF ACTION EXAMPLESAGENTSPOLYENE These antibiotics bind with sterols in the fungal cell Nystatin(cutaneousANTIBIOTICS membrane, principally ergosterol,and causes the cells candida)(T) contents to leak out and the cell dies.So animal cells Amphotericin B (may be become less susceptible. administered liposomally) (Oral candidiasis)(0)IMIDAZOLE AND These antifungal drugs inhibit the enzyme cytochrome IMIDAZOLE:TRIAZOLE P450 14α-demethylase. This enzyme converts KETOCONAZOLE(Athlete’s lanosterol to ergosterol, and is required in fungal cell foot, ringworm) (T) membrane synthesis. These drugs also block steroid TRIAZOLE:Fluconazole synthesis in humans.ALLYLAMINES Inhibits the enzyme squalene epoxidase, another Naftifine (Tinea enzyme required for ergosterol synthesis. corporis)(T)ECHINOCANDIN Inhibits the synthesis of glucan in the cell wall, Micafungin (Candida probably via the enzyme 1,3-β glucan synthase. peritinotis) (IV)