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Fungi eukaryotes are divided into 2 categories
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Yeast (fungi)
- are unicellular
- and reproduce asexually via budding or fission
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Hyphae(fungi)
- are multicellular
- and reproduce sexually or asexually
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Fungi characteristics
- Dimorphism( comfounds classification)
- rigid cell walls (consist of chitin)
- body(thallus) consist of mycelium
- fruiting bodies
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mycelium
loosely organized masses of filaments called hyphae
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importance of Fungi
- they are chemoheteropods
- fermentation abilities are utilized in food industry and medical applications (penacillin)
- extracellulary digest food and obtain nutrients and absorption
- most are saprophyted (ex. decomposers)
- some form symbiotic relationships with plants (mycorinisae)
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Pathogenis Fungi are
- often faculative, rarely obligated
- few are human pathogens
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Reguirement of pathogenic Fungi
- Proximity to host (need to gain access to host)
- environmental resorvior is spores or normal flora
- ability to adhere and penetrate cells and resist removal
- ability to digest and absorb nutrients from host
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Human immune defensed against pathogenic fungi include:
- frequent epithelial cell turnover( skin naturally shed)
- pH of skin and mucosa
- normal flora will fight it off
- cilia will prevent it from entering the respiratory tract
- Treatments are often toxic to human and fungal cells
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Superfcial fungal diseases
- are common fungal diseases that effect only keratinized tissue
- epidermal layer
- hair
- nails
- urogenital(vaginitis,yeast infection) ,
- oral(thrush,oropharyngeal),
- skin,
- fingernails.
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Cutaneous fungal infections
usually involve dermophytes affecting the epidermis
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subcutaneous fungal infections
affects the skin layers beneath the epidermis (usually due to punctures or skin wounds) tissue, bones, and lymphatics
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Systemic fungal diseases
- are rare and originate in the lungs and then invade other organs, kidneys, liver, spleen,brain,eyes,heart,major organs
- deeply invasive
- 4th most common form of nosocomial infections in US
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Oppertunistic fungal diseases
are serious diseases encountered by perple with reduced immune sustems
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2 Types of skin fungal diseases are
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2 types of respiratory fungal diseases are
- Aspergillosis
- Histoplasmosis
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Ringworm agent
- Dermastophytes
- sp. tricopytan, microsporium, epidermopyton
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Ringworms produce
Keratinase used to breakdown proteins found in skin, hair and nails
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Dermatophytes (fungus)
spores can live for more than a year in human skin scales in the environment
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ringworm transmission
- direct
- indirect (fomites)
- vectors (domestic animals)
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ringworm diseases
- tinea corpis- body
- tinea capitis- scalp
- tinea barbae- beard
- tinea cruris- groin/joc itch
- tinea pedis-toes
- tinea unguium-fingernals, toenails
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ringworm treatment
- anti-fungal creams and/or antifungal oral medications
- removal of dead epithelial tissue
- good hygiene
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ringworm prevention
- good hygiene
- treat items for spores
- avoid prore contaminated objects (gyms,lockers,pools)
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Candidiasis agent
Candida albicans
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candidiasis characteristics
- unicellular
- budding yeast
- ubiquitous
- normal microflora
- invasive pathogen
- thrives in damp, warm conditions
- most common opportunistic fungal infection
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candidiasis transmission
direct
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forms of candidiasis disease
superficial-urogenital(vaginitis,yeast infection) , oral(thrush,oropharyngeal), skin, fingernails.
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candidiasis (moniliasis) at risk group
- infants, pple w/ dentures, pregnant wmn, diabetics, long ter use of chemotherapeutics, immunocompromised indeviduals
- most common cause of diaper rash
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candidiasis treatment
- sometimes drying agents
- Antifungal drugs (topical,oral, IV, suppositories)
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candidiasis prevention
- prevent/control optimal growth conditions for yeast (moisture, heat,friction)
- maitenance of hygiene, skin integrity, immune system functioning
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Aspergillosis agent
Aspergillus fumigatus
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Aspergillosis characteristics
- ubiqutous
- small spores are buoyant( remain airborne)
- may produce mycotoxins which can cause liver cancer
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Aspergillosis transmission
- indirect (fomites)
- vehicles (airborne food)
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forms of Aspergillosis
- allergic aspergillosis
- aspergillomas
- invasive pulmonary infection
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Allergic Aspergillosis
- common in asthmatics
- Lungs: weezing, cough,malais,fever etc.
- Sinuses:facial pressure, headache, blocked nose, yellow or green discharge from the nose and cough
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Aspergillomas
may form in the lungs or other organs
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Invasive pulmonary infection
fever chest pain shortness of breath blood in septum and urine, pneumonia, delarium, menengitis, shock, endocarditis
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Aspergillosis treatment
- allergies: immunosuppressant drugs (predizone, steroids)
- invasive pulmonary: Antifungal agents (oral or IV.), Surgical removal of aspergillomas or infected ares (endocarditis)
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Aspergillosis prevention
- Masks
- Mintain hygiene & immine functioning
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Aspergillosis concerns
food poisoning via aflatoxins, contaminated foods ( milk and p. butter)
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Histoplasmosis (valley Fever) agent
histoplasma capsulatum
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histoplasmosis characteristics
- Ubiquitous to soil (found in poultry, house litter, caves, areas harboring bats, and in birds roosts)
- Dimorphic fungal shapes ( changes shape, filimentous(naturally); yeast (in humans))
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histoplasmosis transmission
vehicle (airborne inhilation of spores)
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histoplasmosis forms of disease
- Asymptomatic 90%
- Invasive infection (pneumonia like)-chills,fever, chest pain when breathing.
- Chronic invasive infection (Tb like symptoms)- granulomas
- Dissemination to meninges and internal organs
- *most common is chronic and dissemination
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Histoplasmosis treatment
- Mild cases are self limiting Antifungal agents (long term needed for some cases)
- Supportive therapy
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histoplasmosis prevention
- Regulate vectors (bats or birds)- control population numbers, properly manage waste
- Use protective gear/ mask in high risk areas
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