5The five kingdom system Eukarya (includes all organism with a nucleus & membrane bound organelles)Plants and Animals are fairly obviousFungi, are very distinct from the other kingdomsKingdom Protista is a “dumping ground” for organisms that don’t fit into the other eukaryotic kingdoms
7Exoenzymes are found in fungi and some bacteria Exoenzymes are found in fungi and some bacteria. They are digestive enzymes that are secreted into the environment, where they digest the food into small molecules that can be absorbed and used by the fungus.
95,000 plant pathogens=$1 billion/yr FUNGI100,000 species100 human pathogens, fungi associated diseases are rising, due to nosocomial infections and in immunocompromised patients (ie. HIV, diabetes, lupus, transplant folks)Aspergillosis, Blastomycosis—pulmonary infections and dissemination may be involved5,000 plant pathogens=$1 billion/yr2
10IMPORTANCE OF FUNGI Fermentation industry Remember fermentation is an anaerobic processWine (yeast)BeerBreadCheese (bacteria)Soy sauce (filamentous fungi (Aspergillus oryzae provides a low protein diet with amino acids, yeast & bacteria) soy beans & flour are held in a container for mold to grow—moldy beans are incubated for several monthsSauerkrautVinegar (yeast and bacteria)Yoghurt (Bacteria)5
11IMPORTANCE OF FUNGIDrug manufacturing (usually their waste products are to our benefit)Citric acidEthanol (yeast)Antibiotic griseofulvin, penicillinCortisone (Rhizopus)immunosuppressive agents (cyclosporine)6
12IMPORTANCE OF FUNGI (cont.) SAPROPHYTEDegrade complex organic materials into simple ones, which become available for other organisms7
13Importance of Fungi (cont.) MYCORRHIZAEFungi associated with plants SymbiosisFungi help plant roots absorb minerals and water in the soil-serve as root extensionsFungi benefit by absorbing nutrients exuded by plant roots
16They are often called “ancient plants” 4 broad classes existAlgal fungiSac fungiImperfect fungiClub (basidium) fungi
17Algal fungi All are microscopic and grow in water and damp soil Many species in this group are responsible for blights (like Irish Potato Famine)Some species, such as Rhizopus however, are used as a source of cortisone and other "drugs"
18Sac fungiyeasts and the blue and green molds often seen on decaying citrus fruits, in jellies and on leatherSome species, like Penicillium are economically useful, but others such as Ergot (Clavicep s purpurea) which infects rye crops, can cause mass destructionIn controlled doses, however, Ergot becomes an important alkaloid used to control hemmorrage (during the birthing process) as well as in the treatment of migraineCandida albicans is another species of sac fungi that is parasitic in human beings and aids in the normal functioning of the digestive tract
19Imperfect fungimolds that mildew walls and spot clothes, as well as those that cause plant diseases, athlete's foot, and ringworm.Some of these fungi are useful like Aspergillus, used in the production of miso (fermented soy paste)
20Club (basidium) fungilargest group of fungi which includes rusts and smuts that attack specific plants, such as corn, beans, apples, wheat, asparagus, coffee, roses and barberrymany of the mushrooms in this division are edible and delicious, a large number of them, such as the Amanita's are deadly poisonous
22FUNGAL STRUCTURE Thallus-”body” Septate-Cross Wall (Most Fungi) Molds & fleshy fungi have these structuresLong filaments of cells (hyphae)Septate-Cross Wall (Most Fungi)Coenocytic-No cross wall, continuous mass with many nuclei10
25Forms when environmental conditions are right MYCELIUMIntertwined filamentous mass formed by hyphae, visible to the unaided eyeForms when environmental conditions are right14
26John Cooke, Oxford Scientific Films Black Bread MoldThis black bread mold growing on a piece of stale bread shows the mycelium, or interwoven filaments that make up the vegetative portion of the fungus. The small dark spots are the fruiting bodies, or sporangia, from which the spores are released.John Cooke, Oxford Scientific Films16
27YEAST Facultative Anaerobes Fermentation=ethanol and CO2 Non-filamentous unicellular fungiSpherical or ovalReproductionTwo types exista)Fission or b) budding17
28Yeast Reproduction FISSION “even” reproduction, nucleus divides forming two identical cells, like bacteriaBUDDING“uneven” reproduction, parent cell’s nucleus divides and migrates to form a bud and then breaks away
29Safra Nimrod/Phototake NYC MichaelA. McClure PHD/Phototake NYC Bread YeastBread yeast, or baker’s yeast, actually a type of sac fungi, reproduces by a process called budding. Bread yeast causes bread to rise by releasing carbon dioxide, which gets trapped in the dough. The Egyptians were the first to discover that allowing dough to ferment produced gases that made bread lighter.Safra Nimrod/Phototake NYC MichaelA. McClure PHD/Phototake NYC18
30DIMORPHIC FUNGI Growth as a mold or as a yeast Most pathogenic fungi are dimorphic fungiAt 37o C yeast-likeAt 25o C mold-likeCan also occur with changes in CO2Fungi grow differently in tissue vs nature/culture; often dictated by temp19
31Within Agar=mold, Agar Surface=yeast Changes in CO2Within Agar=mold, Agar Surface=yeast21
32Types of REPRODUCTION Asexually-fragmentation of hyphae Asexually and Sexually-sporesSpores: Used for IdentificationFour groups of true fungiZygomycetes (common bread mold—Rhizopus)Basidiomycetes (puffballs & common mushrooms)Ascomycetes (Dutch elm disease/rye smut)Deuteromycetes (fungi imperfecti)22
33Classification of these groups First three groups is based on their method of sexual reproduction4th group, the Deuteromycetes, have NO sexual reproduction
34REPRODUCTION (cont.) Asexual Reproduction Progeny will be identical to parentSpores (Conidiospores, Blastospores,Chlamydospores, Sporangiospores)Hyphae fragmentation (Arthrospores)23
35IDENTIFICATION OF FUNGI Examination of asexual spores**Fungal spores are different than the endospores of bacteriaEndospores are not for reproduction, but an environmentally resistant life stageFungal spores are for reproduction, do not ensure resistance to environmental conditions24
41ASEXUAL SPORES (cont.) Chlamydospore Formed within hypha Thick-walled sporeCandida albicans27
42ChlamydosporesThe chlamydospore is a method of producing a substantial resting spore very quicklyNutrient is shunted from adjacent cells into a preferred cell and it swells up, converts nutrient materials to oil droplets for efficient storage, then rounds off with a thick, often roughened outer wall for protection
54ALL FUNGI: are eukaryotes develop from spores display neither flagella, cilia, nor chloroplastshave cell walls (though not necessarily ones composed of cellulose as are plant cell walls, but instead of chitin and other polysaccharides)Though displaying great variety and complexity, the fungi are routinely divided into two major groups:the macroscopic (fleshy) fungithe microscopic fungi (molds and yeasts)
55Fungal growth requirements In contrast to bacteria, fungi tend grow in places that are:more acidichave higher osmotic pressuresare lower in moistureare low in nitrogencontain complex carbohydrates
56Fungal structures Hyphae are one dimensional arrangements of cells. septa are the cross walls which separate individual cells in hyphae.Mycelium are a tangled mass of hyphae.Mycelium can extensively permeate the substrate within which the fungi grows whether it be soil, water, or even living tissue.
57Molds vs Yeast Molds Molds are aerobic, filamentous fungi including mildewsrustssmutsMolds tend to grow on surfaces rather than throughout substrates.Yeastsunicellular/nonfilamentous:Yeasts are fungi which are:typically spherical or ovalfacultatively anaerobicThey are often observed as powdery coatings on plant material.
58Dimorphic fungiDimorphic fungi are fungi that behave like molds (multicellular---consist of hyphae) under some conditions, and like yeasts (unicellular---lack hyphae) under others.
60Fungal reproductionfungi replicate by mitosis rather than the binary fission employed by bacteria.Types of fungal reproduction, :buddingfissionhyphae fragmentationsporulation
61Sexual and asexual: Fungal spores come in two varieties: asexual spores and sexual sporesSpores are used extensively to identify fungi.Asexual sporesasexual spores are formed by a single parental fungi and therefore genetically identical to the parental fungi.Asexual spores come in a variety of types formed by a variety of mechanisms including:Arthrospores (sliced bread pieces)Blastospores (buds on a twig)Chlamydospores (giant cell with oil)Conidiospores (fingers)Sporangiospores (sac)
64Zygomycetes Asexual phase—Sporangium—bread mold (Rhizopus stolonifer) Sexual phase--- sporgangium ---shotgun fungus (lives on dung) it shoots its sporgangium explosively towards light or fly pathogen (Entomophthora muscae—--these types of fungi have been used as agents for biological control of insects)
65BasidiomycetesBasidiosporeExamples: boletes, puffballs,smuts, stinkhorns and tooth fungi
71Ascomycetes “sac” fungi Septate hyphae and yeasts Asexual spore: ConidiosporesApproximately 30,000 species including yeasts (Saccharomyces cerevisiae), some of the molds (Aspergillus), morels, and truffles. Ascomycetes have typical reproductive structures called asci.
73Basidiomycetes “club”fungi Mushrooms Approximately 25,000 species including many macroscopic fungi (mushrooms, puffballs, shelf fungi) as well as a number of plant pathogens (rusts, smuts).
74Mycosis: Fungal infection Usually chronic FUNGAL DISEASESMycosis: Fungal infectionUsually chronicFour groups of mycoses based on degree of tissue involvement and mode of entry44
75Because fungi are slow growing, mycoses are generally long-lastingTYPES OF MYCOSESSystemicSubcutaneousCutaneousOpportunistic45
76SYSTEMIC MYCOSES Deep within the body effects a number of different tissues and organsUsually soil fungiSpore inhalation=Route of transmission-starts in the lungs and spreads to other body tissuesNot contagious46
77SYSTEMIC MYCOSES (cont.) HistoplasmosisCoccidiomycosisCoccidioides immitis got renamed for the AZ Valley fever Coccidioides posadasii47
78Infections beneath the skin Soil and plant fungi SUBCUTANEOUS MYCOSESInfections beneath the skinSoil and plant fungiHyphae or spores in wounds48
79CUTANEOUS MYCOSES Called “Dermatophytes” Epidermis Hair Nails Secrete keratinase-degrades keratin (protein found in hair, skin and nails)Contagious-direct contact with infected hairs and epidermal cells3049
80Skin high osmotic pressure Low moisture CUTANEOUS MYCOSESSkin high osmotic pressureLow moisture52
94MycetomaMycetoma is a chronic infection of the skin, subcutaneous tissue and sometimes boneIt is generally found on the foot where it is given the name watering can footMycetoma may be due to several fungi or actinomycetes (actinomycetoma).Actinomycetes are bacteria producing filaments like fungi. Both the fungi and the actinomycetes are found in soil and plant material in tropical regions.The organism is inoculated into the skin by a minor injury, for example, a cut with a thorn when barefoot.
96Clinical featuresMycetoma is more common in men than women, particularly those aged 20 to 50. It generally presents as a single lesion on an exposed site and may persist for years.It starts as a small hard painless lump under the skin.It grows slowly but eventually involves underlying muscles and bones.The middle of the lesion caves in, ulcerates and discharges pus, which contains grains.Eventually, sinus tracts (holes) develop which also discharge pus and grains.The surface skin is scarred and pale.Considerable deformity often makes it difficult to walk.Mycetoma may cause no discomfort but it often itches or burns.Secondary bacterial infection is common.Treatment is slow
97Mucosal normal microbiota suppresses the growth of Candida albicans CANDIDIASISMucosal normal microbiota suppresses the growth of Candida albicans62
98CANDIDIASIS (cont.) Vaginitis and thrush are initiated by: Antibiotics eliminate normal microbiotapH changesInfants that may not have their normal microbiota established=thrush63
102MYCOSES OF THE RESPIRATORY SYSTEM Histoplasmosis-resembles TB, starts in the lungs, most cases are minorHistoplasma capsulatumCoccidioidomycosisCoccidioides immitis in CACoccidioides posadasii in AZ66
103MYCOSES OF THE RESPIRATORY SYSTEM (cont.) BlastomycosisBlastomyces dermatidisPneumocystis pneumoniaPneumocystis carinii67
104Resembles tuberculosis May affect all organs Vague symptoms HISTOPLASMOSISResembles tuberculosisMay affect all organsVague symptomsYeast lives within macrophages and multiplies68
105HISTOPLASMOSIS (cont.) Histoplasma capsulatumDimorphic fungiMississippi river and Ohio river states69
106HISTOPLASMOSIS (cont.) Very low mortality50/year/USATransmissionAirborne conidiaBats: Carry fungus in fecesBirds: Feces70
108Histoplasmosis second most significant fungus disease It is infectious but not contagiousThe "summer flu" that Midwesterners use to get often is now thought to have been histosplasmosisHistoplasmosis basically is a pulmonary or respiratory disease, but may extend to the liver, lymph nodes, and spleen; it may disseminate to the blood and bone marrow and be fatalThe victim frequently has chills and fever to 105 degrees, night sweats, chest pains, and fatigued. A non-productive cough is fairly common.
117COCCIDIOIDOMYCOSIS In tissues C. immitis forms spherules Thick-walled structures filled with sporesIn soil, forms filaments that reproduce by the formation of arthrospores, transmitted by wind, 100,000 infections per year76
118Life cycle of C. immitis Spherule form (top half) multiplies in the lungs; mycelia(bottom half)grow in the soil
127Blastomycosis—Glichrists Disease Blastomycosis is a chronic, systemic fungal disease that affects humansThe disease affects the lungs.It is caused by Blastomyces dermatitidis.The main route of infection is by inhalation of sporesThe disease is infectious but is not contagious.Major symptoms in humans include loss of weight, fever, cough, and bloody sputum and chest pains.The disease may disseminate into the skin, bones, or urogenital tract.
128Isolation of organism from pus and biopsies Treatment Amphotericin B BLASTOMYCOSIS (cont.)DiagnosticIsolation of organism from pus and biopsiesTreatmentAmphotericin B86
129PNEUMOCYSTIS PNEUMONIA Pneumocystis cariniiOpportunistic pathogenLeading cause of death in AIDS patientsPresent in healthy lungsImmunosuppressed individuals89
130PNEUMOCYSTIS PNEUMONIA (cont.) Rare before AIDS epidemicLess than 100 cases/year1993-Indicator of AIDSCurrently, one of the most common infectious diseases90
132Those darn pigeons!!Cryptococcosis: Yeast Meningitis Affects: Humans The disease is caused by a systemic pathogenic yeast called Cryptococcus Neoformans, which is found worldwide.Cryptococcosis in humans usually begins as a primary infection of the lungs.There are no visible early symptoms may include cough, chest pain, weight loss, fever or dizziness. The disease may be in the lungs, mucous membranes, bones, and joints, with no organ or tissue of the body exempt.It very frequently involves the brain covering as cryptococcal meningitis.Pigeon excreta is the most common source of C. Neoformans. The yeast is carried in the intestinal tract of pigeons.Pulmonary cryptococcsis has occurred in the workmen who have been exposed to the yeast while demolishing old buildings where pigeons had roosted.Most of the cryptococcal infections occur from inhalation of the fungas along with the dust from areas enriched with pigeons manure.
133Other diseases associated with pigeons Salmonellosis is more than just food poisoning.Pigeons are important factors in the spread of salmonellosis, since the bacteria are left wherever the pigeons defecatePigeons trample back and forth through their copious excretions on ledges and air intake ventsThe dust enters through air conditioners and ventilators.S. Typhimurium var. Copenhagen is the most common salmonella isolated from pigeonsSalmonellosis in humans may manifest itself in one or more of four types (1) temporary carriage without infection (2) Gastroenteritis (food poisoning) (3) enteric fever septicemia (blood poisoning) (4) Persistent infection
136Antifungal antimicrobials Amphotericin B, nystatin (Streptomyces nodosus)miconazole Monistat 3 (azole)Relatively toxic-KidneysAmphotericin should be used primarily for treatment of patients with progressive and potentially life-threatening fungal infections; it should not be used to treat noninvasive forms of fungal disease such as oral thrush, vaginal candidiasis and esophageal candidiasis, in patients with normal neutrophil counts.Miconazole nitrate inhibits the biosynthesis of ergosterol, an essential component of the fungal cell wall. Miconazole nitrate has also been shown to interact with the synthesis of triglycerides and fatty acids, and to inhibit fungal oxidative and peroxidase enzymes.
137FUNGAL DISEASES OF THE DIGESTIVE SYSTEM Mycotoxins: Fungal ToxinsErgot poisoningAflatoxin poisoning93
138Ergotism: Disease caused by ingestion of contaminated grains ERGOT POISONINGClaviceps purpureaInfects Grain CropsErgotism: Disease caused by ingestion of contaminated grainsClaviceps-contaminated grains (rye or wheat)94
139Claviceps purpureaas recently as 1951, in Pont-St. Esprit, a small town in France, there was an outbreak of the disease. In Europe it is the custom to buy fresh bread nearly every day.
140In this small town there was only one bakery and everyone bought bread from it. Strange things started happening. People developed a burning sensation in their limbs, began to hallucinate that they could fly, did strange things to their dogs with forks and in general acted weirdly. This outbreak is chronicled in a marvelous (but out of print) book called "The day of St Anthony's Fire" by John Grant Fuller. St. Anthony is the patron saint of lost causes When all of the other saints have failed, St. Anthony is the one you are supposed to pray to. And St. Anthony's fire was rampant in the town that day. Similar outbreaks probably occurred throughout the world wherever the conditions were right for the growth of Claviceps purpurea.
141The chemical responsible for the hallucinations is actually LSD The chemical responsible for the hallucinations is actually LSD! lysergic acid. There was even an outbreak of ergotism on the television show "Quincy" starring Jack Klugman, who played a coroner. He was aboard a cruise ship and people were acting very strangely. Quincy finally traced the behavior to contamination of the flour tortillas that had been served aboard ship.
142The X-Files also had an episode featuring ergot, although it had a surreal twist (of course). In that episode, Scully got a tattoo that caused her to hallucinate (she thought the tattoo was talking to her). Turns out the tattoo artist was an ex-con who learned his art in prison. He collected plants in the prison yard and extracted dyes from them for his tattoos.
143Another ergot derivative may cause spontaneous abortions in animals-- in small doses this same drug is used to aid in childbirth. Another of the ergot derivatives is used to cure migraine headaches.
145ERGOT POISONING (cont.) Witchcraft in Salem (1690s)Similar Behavior caused by Lysergic acid (LSD)96
146There have been various attempts to explain those witch trials There have been various attempts to explain those witch trials. None of them are more logical and interesting than the hypothesis of ergot poisoning, caused by Claviceps purpurea. The behavior was not identified as witchcraft until 1691, and this was just the beginning of the problem.All of the accused had similar symptoms: manic melancholia, psychosis, delirium, crawling sensations of the skin, vertigo, headaches, vomiting and diarrhea. All of these are symptoms of ergot poisoning, and it is likely that at least the initial hysteria was started by Claviceps purpurea infecting the grains of ryecompelling, although circumstantial, evidence that the Salem witch trials coincided with a weather period that would have produced large quantities of ergot on rye, which was grown in the lowlands in that area.
147"The Trial of George Jacobs, August 5, 1692. " By T. H. Matteson, 1855 "The Trial of George Jacobs, August 5, 1692." By T. H. Matteson, Oil painting. Peabody and Essex Museum, with permission.
148AflatoxinAflatoxin is a naturally occurring mycotoxin produced by two types of mold Aspergillus flavus and Aspergillus parasiticus.Aspergillus flavus is common & widespread in nature and is most often found when certain grains are grown under stressful conditions such as drought.The mold occurs in soil, decaying vegetation and hayAt least 13 different types of aflatoxin are produced in nature with aflatoxin B1 considered as the most toxicWhile the presence of Aspergillus flavus does not always indicate harmful levels of aflatoxin it does mean that the potential for aflatoxin production is present.
149Aflatoxin poisening Aspergillus flavus Peanuts and cottonseeds Acute intoxicationLiver damage97
150AFLATOXIN POISONING (cont.) Chronic intoxicationLiver cancerDepending on the levels, the toxins can severely affect the liver and they are a known human carcinogen99