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63 Cards in this Set
- Front
- Back
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What are the primary nosocomial infection from fungus?
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Candida and Aspergillus
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What do ABX do for fungal infections?
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They limit bacteria infections, but FAVOR fungal infections
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What are some superficial and cutaneous fungal infections?
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Dematophyte: Athlestes Foot, Ringworm
Vaginal yeast infections: Candida Albicans (both opportunistic & cutaneous) Fungi that infect outer later of skin, hair, nails NOT very invasive |
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What are some Subcutaneous fungal infections?
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Sporotrichosis (assoc. w/rose bushes)
Myectoma Chromoblastomycosis Cause infection under the skin by some wound/lesion Can infect non-compromised |
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What are some Sytemic Mycoses fungal infections?
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Respiratory infections by DIMORPHIC fungi DO NOT have to be compromised to get a respiratory infection
Most people are asymptomatic or mild Coccidioidomycois, histoplasmosis, blastomycois |
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Opportunistic Fungal Infections
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Cause invasive disease in COMPROMISED hosts disseminate through blood; rapidly fatal
Cryptococcosis Candidiases Aspergillosis Zygomycosis Pneumocystis |
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What are compromised patients
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HIV, Transplant recepients, Cancer (immunocompromised)
Diabetics, Long term ABX use, Catheterized pts, burn pts, chronic bronchitis/asthma, pts receiving corticosteroids |
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What are bone marrow tranplant pts susciptable to?
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Aspirgillus
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What are Diabetics suscitible to?
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Molds that cause Rhinocerebral disease
Causes lesion on face which can be invasive into the bone and brain; fatal within days |
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What are Catheterized pts suscitible to?
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Candida, Malassezia furfur
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What is Malassezia furfur
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Cathetericed pts suscitible
It is a yeast, and can cause hypopigmentation on chest or back if it becomes oppurtunistic |
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What are burn pts. suscitible to?
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Skin is compromised
Candida, Aspergillus |
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What are people with chronic bronchitis/asthma suscitible to?
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Aspergillus; A ubuquitous mold, very common
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What is sick building syndrome?
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Can occur with common mold (Aspergillus); do not have to grow in the host to trigger a rxn
mold contamination produces high levels of spores or conidia and released into the air Individuals will have a positive hypersensitivit rxn seen with a skin test Usually non-pathogenic (opportunistic pathogen) |
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What are some general characteristics of mold?
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Cell: Eukaryotic
Cell Wall: Chitin, mannans, glucans Plasma Membrane: Ergosterol Reproduction: Sexual &/or Asexual spores |
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What are different from Fungi and Mammalian Cells?
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There plasma membrane is made from ergosterol (sterol), instead of cholerterol
There cell wall is made of chitin |
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What is mold?
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the filamentous form of fungi
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What is yeast?
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Oval-shaped, single-celled form of fungi
Reproduce by budding |
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What is dimorphic fungi?
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Fungi that grow as a mold at 25 C (in nature) and yeasts at 37 C (in the body)
Candida = noraml flora, grows as yeast |
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What is dematiaceous fungi and what does it cause?
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Black or brown pigmented fungi
Causes phaeohyphomucosis Becomes more prominent w/ opportunistic infections Found in soil |
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What are hyphae?
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Filaments or tubular structures of molds
Two types: Septated and Nonseptated |
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What are septated hyphae?
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Hypahe with cross walls
Long filament broken up with cross walls Aspergillus |
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What are nonseptated or coenocytic hyphae?
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Hyphae w/o cross walls
Like a big, long empty tube; less ridgid Zygomycetes |
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What is Pseudohyphae?
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Hyphae like structures formed by incomplete budding of yeast cells
They are constricted at their point of attachment (true hyphae are not) Candida Albicans |
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What type of hyphae does Candida Albicans form?
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Will form both hyphae and pseudohyphae
Dimorphic |
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What is mycelium?
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A mass of intertwined hyphae
Mold = mycelium |
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What is Aerial mycelium?
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Mold the contains the spores and reproductive structures
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What is Vegitative mycelium?
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Gron INTO agar and absorn nutrients (like roots)
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What is Conidia?
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The asexual spores of aerial mycelium
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What are Conidiophores?
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Support chains of conidia
Grow out into chains off of bud Aspergillus |
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What are Sporangiospores?
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Spores within a sac like structure
Zygomycetes |
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What is Blastoconidia and what are three examples?
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Budding yeast cell
Histoplasma Capsulatum & Blastomyces (both dimorphic) & Cryptococcus Neoformans (yeast in both forms) |
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What is signifigant about Cryptococcus Neoformans?
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It exists as yeast in both environment and infectious form
AIDS definging illness it is meningitis in HIV pts |
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What are microconidia and Macroconidia?
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Single or multi cellular conidia
Used to speciate Dematophytes (ringworm, athletes foot) Macro = multiple spores in same structure |
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What is Arthroconidia and what has it in its infectious form?
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Conidia formed by fragmentation of hyphae
Infectious form of Coccidioides Immitis |
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What are endospores?
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Spores produced within a spherule (tiny sphere)
Coccidiodes Immitis |
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What does Coccidiodes Immitis form and what special has to be done?
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Forms an endospore; does NOT form a yeast cell
If suspect this must inform clinical lab so they can handle in hood, b/c very infectious and airborne |
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What are some sexual spores/reproduction and how are they used?
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Tascospores, Basidiospores, Zygospores
Used to classify the fungi, if unknown placed into the class Deuteromycete |
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What was Malassezia furfur called before and what does it commonly cause?
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Pitytosporum Obuculare
Opportunistic pathogen but can also cause skin pigementation changes Seen in ICU's (clog catheters) and kids on lipid supplement |
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What should you look for in diagnosis?
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Clinical symptoms important
Looking for fungus in clinical specimen VERY important Still want to confirm by culture (may take days) |
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What should you specifically look for on fungus for a diagnosis?
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Look for type of conidia and the hyphae, and the type of spore
Lactophenol Cotton Blue |
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What is the most common stain for clinical specimen, what can it pick up, and how does it work?
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KOH preparation
Can pick up yeast infections Degrade cells but WILL NOT degrade the fungal wall (Chitin) |
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What can be combined with KOH?
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Calcoflour white
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What is Gormori's Methenamine Silver?
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Typical histological stain
Fungi turn dark brown or black |
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What does the EIA test lood for?
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Looks for Antibodies to: Histoplasma, Blastomycosis & Coccidiodomycosis
NOT that good of a test b/c sometimes make AB cross reactive, producing false positives |
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What are you looking for in the EIA test?
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Looking for IgM (acute/current infection)
or Four fold increse in IgG (recent infection) |
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What are skin tests useful for?
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ONLY indicate a past or present infection
Can NOT diagnose |
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What is the Latex Agglutination test for?
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Test for Cryptococcal capsule
Looks for these antigens in the CSF; b/c it often will disseminate into it |
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What is Ergoterol?
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The unique component of fungi cell wall
Common target for Anti-fungals Different groups of these drugs interrupt different stages of ergosterol synthesis |
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What are some common characteristics Candida Albicans?
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Normal flora of lower GI, oral, and femal genital (yeast infections)
Endogeneous infection (unusal b/c most fungi are exogeneous) Person to person transmission Dimorphic |
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What happens to Candida Albicans when it becomes invasive?
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When invasive you see see septated hyphae and pseudohyphae
This can give you a good idea if it is candida versus another common mold |
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What is the germ tube test?
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Used to identify candida albicans as oppose to non-albicans
Albicans make germ tubes which is the switch from yeast to hyphae growth Diagnoistic Test |
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What are some common characteristics of Candida Galbrata?
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2nd most Candida
Does NOT form hyphae, pseudohyphae or germ tubes |
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What are some opportunistic pathogens of Candida?
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C. Albicans, C. Parasilosis, C. Tropicalis, C. Krusei, C. Galbrata
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What Candida do you have to worry about Anti-fungal resistance for?
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Candida Glabrata and Candida Krusei
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Characteristics of Candidasis of Muchous Membranes: Oral Thrush
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Commen in Infants (from birth canal); white plaque inside mouth
AIDS defining illness in adults but can see in Adults with diabetes and ABX use |
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Characteristics of Candidasis of Muchous Membranes: Vaginal Candidiases
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Yeast infections
Immunicompromised pts. more prone to recurrance Others suscitible: Pregnancy, diabetics, ABX therapy, hormonal treatment What plaque areas |
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Characteristics of Cutaneous Candidasis
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Chronic nail infection (onychomucosis); with either dermatophyte or candida
Anywhere warm, moist (diaper rash, overweight) |
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When and what is involved with Chronic Mucocutaneous Candidiasis?
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Children w/ endocrine disorder or defect in T-cell (compromised)
Involved face, nails Plaques are MORE crusty May disapper on its own especially as child gets older |
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When does Systemic Candidiases occur?
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When someone is compromised (HIV), imminosuppreissive treatment (transplants), pts with catheters, IV or prosthetics, and Pts. recieving corticosteroids
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Characteristics of Candidiases disease
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Can infect any organ once in blood; tends to go for kidney, brain, heart, lung, eye
Complications in tranplant pts, abdominal surgery, cardiac surgery |
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What are common characteristics of Candidiases in AIDS patients?
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Oral thrush, esophagitis, recurrent yeast infections (females)
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What test is not that helpful in identifying Candida?
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Serology b/c everyone has Candida in normal flora
Look for positive culture in normally sterile sites |
