exam 1 Flashcards by whitney webb

Are fungi classified as eukaryotic or prokaryotic?

eukaryotic

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what is the structural element that comprises a fungus?

hyphae

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which class of fungi has non-septate mycelium?

zygomycetes

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why are certain fungi classified as “Fungi Imperfecti”?

because it was once thought they didn’t sexually reproduce (perfect cycle is a reproducing one)

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how does the function of reproductive mycelia differ from that of vegetative mycelia?

Veg. anchor fungus to the substrate (below surface) also have a digestive enzyme rep. project above the surface have spores

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to which class do most pathogenic fungus belong too?

deuteromycetes

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what term best describes the nutritional characteristics of fungi?

saprotrophic

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are fungi aerobic or anaerobic

aerobic

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what is the best single medium for the primary isolation of fungi?

sabouraud’s with dextrose

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what is the purpose of corn meal agar?

nutritionally deprive organisms so sporulation (candida albicans)

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how long should routine fungal cultures be held before being discarded?

4 weeks

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what three things does the mounting medium lactophenol cotton blue do?

preserve fungal cultures reduce contamination of environment stain the hyaline fungal structures

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when a systemic mycosis has spread to various organs, what term is used to describe it?

disseminated or systemic

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what organism is best described as a thick-walled yeast cell with buds attached by a broad base?

blastomyces

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which systemic fungus is always a yeast? (i.e. not diphasic)?

Cryptococcus neoformans

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how is histoplasmosis acquired?

inhalation of spores and fungus is usually free living

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name the five spcies of dimorphic (diplasic) fungi

blastomyces dermatididis histoplasma capsulatum paracoccidiodes braziliensis sporothrix schenckii coccidiodes imitis

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which systemic fungus produces thick-walled yeast cells with multiple buds in tissue?

paracoccidiodes braziliensis

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which fungus can be observed as a non-budding, thick-walled spherule containing endospores in a direct smear from the body?

coccidiodes imitis

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which fungus produces spiny, tuberculate macrocondidia when cultured, but in the body can be seen as intracellular , yeast-like cells with a large vacuole in the cells of the RE system?

histoplasma capsulatum

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cryptococcosis is usually seen as a disease of which body system?

pulmonary

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which systemic fungus is the most fastidious (difficult to grow) in the laboratory?

histoplasma capsulatum

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what systemic fungus causes San Jacquain Valley Fever?

coccidiodes

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which systemic fungus causes South American blastomycoses?

paracoccidiodes braziliensis

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which stain is best to use to demonstrate Cryptococcus neoformans in CSF?

india ink

which systemic fungus is endemic in Piedmont NC and can produce a primary pulmonary infection or a primary skin infection which resembles ringworm?

blastomyces dermatididis

which systemic fungus produces chains of arthrospores and can be confused with the saprophytic fungus geotrichum candidum?

coccidiodes

what is the macroscopic appearance of sporothrix scheneckii at 37 degrees?

Yeast: creamy white/tan smooth colonies

list several species of dematiaceous fungi

cladosporium phialophora fonsecaea

which subcutaneous infection produces yeast-like brown cells in clusters in the body?

chromomycosis

what is the most common cause of maduromycosis?

petriellidum boydii

what color are the granules that are frequently found in the pus of madurmycosis?

yellow to whitish

what fungus produces a tear-shaped conidia arranged in rosettes at 25 degrees and yeast cells when grown at 37 degrees and causes a disease common among gardeners which is referred to as "rose fever"?

sporothrix schenckii

name several species that can be responsible for chromomycosis

cladosporium carrion phialophora verucasa fonsecaea pedrosoi (f. compacta)

which organisms can cause mycetomas (fungal tumors)?

madurella mycetomatis

an organism which produces brown, branching septate hyphae would be classified as what type of fungus?

dematiaceous

what device can be used as an aid to select hairs infected with ringworm?

UV light fluorescent light

what type of hair infection is characterized by empty areas or tunnels where the hyphae have degenerated visible throughout the entire length of the hair?

favic

what combination of fungal media would be best to sue to culture the dermatophytes?

mycosel and sabourdas

which three genera of fungi all cause ringworm of the skin?

micropsorum trichophyton epidermophyton

what fungus appears velvety white on the front and mahogany on the reverse and will not grow on sterile unfortified rice grains?

microsporum audouinii

what fungus is the most common cause of ringworm in dogs and cats and is characterized by a canary yellow reverse and spiny, spindle-shaped macroconidia?

microsporum canis

what fungus is the most frequently isolated from human ringworm infections and has a deep red reverse pigmentation?

trichophyton rubrum

what structures are frequently observed in trichophyton cultures?

spiral, coiled hyphae nodular bodies racket hyphae

as a rule, which dermatophyte does not infect nails?

microsporum auduinii

which dermatohpyte is the most common cause of epidemic scalp ringworm in American school children?

trichophyton tonsurans

what fungus causes tinae versicolor?

pityrosporon furfur

what fungus is the most common causative agent of tinae cruris?

epidermophyton

what term is used to refer to ringworm of the skin?

tinae corporis

what dermatophyte gives a positive in vitro hair test?

trichophyton mentagrophytes

which dermatophyte produces sterile, antler-like hyphae referred to as favic chandeliers and causes a severe type of ringworm of the scalp called favus?

trichophyton schoenleinii

which dermatophyte does not invade hair and produces oval, smooth-walled, club-shaped macroconidia and no microconidia

epidermophyton floccosum

which dermatophyte is the most common cause of ringworm of cattle and requires both inositol and thiamine to grow well?

trichophyton verrucosum

how is candida albicans identified?

+ germ tubes chlamydospores production

which fungus is the most common and troublesome laboratory contaminant and is the most pathogenic of the opportunistic fungi?

aspergillis

if an autopsy revealed systemic infection by fungus with borad, branching, non-septate hyphae, which species of fungus could be a likely cause of death?

rhizopus

which fungus commonly produces oval budding cells with pseudophyphae and will produce chlamydospores on cornmeal agar?

candida alibicans

brown gritty deposits in a sputum specimen are indicative of what genus?

aspergillus

what clinical conditions can be caused by candida albicans ?

oral infection thrush monilia

which species of opportunistic fungi can be causative agents of eye infections?

altenaria curvularia fusarium

which fungus is most frequently isolated in the clinical laboratory?

candida albicans

which species of rickettsia causes epidemic typhus?

prowazekii

which species of rickettsia causes scrub typhus?

tsutsugamuschi

which species of rickettsia causes rickettsial pox?

akari

which species of rickettsia causes Q fever?

coxiella burnetti

which species of rickettsia causes RMSF?

rickettsi

how do rickettsia and chlamydia differ?

rickettsia requires anthropod vectors

what clinical conditions can be caused by chlamydia trachomatis?

trachoma, inclusion conjunctivitis most common cause of NGU (non-gonoccocal urethritis)

how is psittacosis spread to humans?

contact with pet birds (parakeets, parrots, cockatoos) inhalation/aerosol

how are rickettsial infections diagnosed in the laboratory?

weil-felix reaction giemsa stain cell culture -\> embryonated eggs

what causes the rash that is frequently observed in rickettsial infections?

when the organisms invade endothelial cells of blood vessels

what are the characteristics of viruses?

obligate intracellular parasites have DNA or RNA (not both) don't respond to AB need electron microscope to see them

what term is used to refer to the viral nucleic acid core together with its protein coat?

nucleocapsid

what is the order of events in the process of viral infections?

1) adsorption to host 2) penetration (viropexis or injection)] 3) replication 4) assembly 5)release

what is interferon?

protein produced by cell that are already infected with virus that protects adjacent, noninfected cells \*natural body defense that prevents viral replication\*

which virus produces an acute respiratory infection and is commonly found in increased incidence in military camps?

adenoviruses

which virus is the causative agent of the common cold?

rhinovirus

which type of virus is referred to as "virus in search of disease"

ECHO enteric cytopathogenic human orphan

negri bodies are characteristic of which virus?

rhabdovirus (rabies)

which virus can cause chicken pox?

varicella-zoster (V-Z)

with what clinical conditions is Epstein-barr virus associated?

burkitt's lymphoma

which virus produces large, red intracellular inclusions?

cytomegalovirus (MV)

how is Hepatitis A transmitted?

fecal-oral route through contaminated food and water

herpes-zoster occurs in patients who have a history of what other viral infection?

chicken pox

what are the characteristics of Hepatitis B?

"serum hepatitis" IV drug users

how many serotypes of polio virus are there?

which vaccines have been deployed against polio?

salk and sabin

which virus has been associated with cancer of the cervix and causes genital lesions in humans?

herpes simplex virus

what serological test is used in the identification of rickettsia ?

weil-felix

what antigens for the weil-felix reaction are deployed that cross-react with rickettsial antigens?

proteus vulgaris

what virus is associated with severe congenital abnormalities in the fetus if the mother becomes infected during her first trimester?

german measles (Rubella)

an "emerging pathogen" is one that seems to be ont he rise in the last several years. What viral pathogen that causes an upper respiratory tract infection in infants and young children would fall into this category?

respiratory syncytial virus (RSV)

to what group of virus does HIV belong?

retrovirus group

what enzyme does the HIV virus posses? (capable of converting RNA to DNA)

reverse transcriptase

name two disease processes that are common in HIV patients that are rarely seen in "normal individuals"

cryptococcus toxis plasmosis CMV

what is the vector for rickettsia Prowazekii

rat flea

what is the vector for rickettsia tsutsugamuschi

larval mite

what is the vector for rickettsia akari