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168 Cards in this Set

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Another name for fungal diseases is _____.
mycoses
What are the four divisions of fungi
Zygomycota, Ascomycota, Basidiomycota, Deuteromycota
Mycosses are typically acquired via:
inhalation, trauma, or ingestion.
True or False

Most mycoses are contagious
False- they are not generally transmissable from person to person.
What group of species are likely to be contagious most of the time? Some of the time?
Dermatophytes

Candida and Pneumocystis
Why are mycoses generally not reported to the CDC?
They are not contagious
List four cataegories of true fungal pathogens.
Blastomyces dermatidis, coccidiodes immitis, histoplama capsulatum, and paracoccidioides brasiliensis
If it ain't a true fungal pathogen, it is considered a ______.
Opportunistic Fungi
Defne what it means to be dimorphic
Having mycelial thalli composed of hyphae in an environment where temperatures are frequently below 30 degrees celsius.
List four factors that predispose individuals to opportunistic mycoses.
Medical procedures
Medical therapies
preexisting conditions
lifestyle factors
Why do opportunistic fungi lack genetic characteristics?
Because thhey lack genes for proteins that aid in colonizing the body.
True or False

Fungal pathogens and opportunists differ with respect to geographical distribution.
True
Are dermatophytes considered pathogenic or opportunistic?
Neither
What are the three categories of clinical manifestations of fungal diseases?
1. Fungal Infections
2. Toxicoses
3. Allergies
What kind of agar is fungi cultured on and why?
Saboraud dextrose agar- because it facors fungal growth over bacterial growth
Which test dissolves keratin in skin cells and allows for the identification of fungal cells?
KOH preparations
____ stain is used to stain fungal tissues black
GMS Gomori methenamine silver
Why is it difficult to distinguish between actual fungal infection and simple fungal exposure?
Because fungi are prevalent in the environment and many are commensal.
Fungal masses are likely to be misdiagnosed as ___ and ___.
tuberculosis or endogenous tumors.
Why is it difficult to recover from fungal diseases?
They resist T cell attacks and are biochemically similiar to humans cells which means that most fungicides are also toxic to human tissues
Humans contain cholesteral in their cell membranes whereas fungi congtain ____.
ergosterol
What are some side effects of long term use of antifungal agents?
anemia, headache, rashes, GI upset, and serious liver and kidney damage
"Gold Standard" of antifungal agents.
Amphocetricin B

(fungilcidal)
Alternatives to amphocetricin B.
Ketoconazole, itraconazole, and fluconazole

(fungalstatic)
This drug inhibits DNA and RNA synthesis, doesn't target ergosterol, and is used in conjunction with amphotericin B.
5-fluorocytosine
5-fluorocytosine is often used to treat _______ infections.
Cryptococcal
This antifungal drug interferes with microtubule formation and chromosomal separation in cell division.
Griseofulvin
What division are the four pathogenic fungi from?
Ascomycota
True or False

All pathogenic fungi are uniformly acquired via inhalation
True
Blastomycoses are caused by _______.
Blastomycoses dermatidis
Blastomycoses dermatidis is endemic ___.
across the united states North to Canada

But outbreaks have been reported in Latin America, Africa, Asia, and Europe
Why are the incidences of human infection of blastomycoses increasing?
Because the number of immunocompromised individuals in the population are also rising.
_____ is the most common mansifestation of blastomyces infection in humans.
Pulomary blastomycosis
What are some symptoms of pulmonary blastomycosis
cough, fever, malaise and weight loss.
True or False

Pulmonary Blastomycosis is usually fatal.
False- it usually resolves itself but it may become chronic
What is a clinical manifestation of cutaneous blastomycosis?
Painless lesions of the face and upper body
When blastomycosis spreads beyond the lungs, it becomes ________.
cutaneous blastomycosis
When blastomycosis spreads to the spine, pelvis, cranium, ribs, long bones, or subcutaneous tissues it becomes ____.
osteoarticular blastomycosis
What is the treatment of blastomycoses infections?
10 weeks of amphotericin B

or 3-6 monthos of oral itraconazole
Coccisiodomycosis infections are caused by _____.
coccidiodes immitis
Coccidiodes immitis is endemic to...
southwestern USA (arizona, nevada, CA, new mexico)

small and semi arid regions of south america
Coccidiomycosis can spread many miles and to many people as a result of this.
windstorms and earthquakes
In dry weather, c.immitus grows as ____ and produces asexual spores called ____.
1. mycelium
2. arthroconida or arthrospores
When arthrospores germinate, they become a parasitic form known as ______.
spherule
Spherule life cycle:
matures --> enlarges --> multiple cleavages --> ruptures --> MANY SPORES
What is the major manifestation of coccidiodomycosis?
pulmonary
What is the drug of choice for coccidiomycosis?

If you've got the AIDS?
amphotericn B

itraconazole or fluconazole
What is the causative agent of histoplasmosis?
histoplasma capsulatum
Where do you find histoplasma capsulatum?
in the eastern US along Ohio River, however also endemic to Africa and South Africa
What are the two strains of H. Capsulatum?
Capsulatum- most widely distributed

duboisii- limited to africa
Life cycle of histoplasmosis:
1. inhalation
2. attacks alveolar macrophages
3. macrophages disperse fungus via blood and lymph
4.cell mediated immunity kicks ass
What are the manifestaions of clinical histoplasmosis?
1. Chronic pulmonary histoplasmosis: severe coughing, blood tinged sputum, night sweats, loss of apetite, weight loss

2. Chronic cutaneous histoplasmosis: ulcerative skin lesions

3. Systemic histoplasmosis: enlargement of the spleen and liver. Fatal

4. Ocular histoplasmosis: inflammation and redness
What is a distinctive feautre of cultured histoplasma capsulatum.
spiny spores
True or False

In endemic regions of the US close to 90% of the population tests positive for H.capsulatum
True- although in most people it's probably asymptomatic
What is the causative agent of paracoccidiodomycosis?
paracoccidiodes brasiliensis?
What fungus is found in cool, damp soils from southern mexico to regions of south america and brazil?
p. brasiliensis
Disease cycle of paracoccidiodes brasliliensis
1. long incubation period
2. pulmonary disease
3. chronic cough, fever, night sweats, malaise, weight loss
4. chronic inflammatory disease of mucous membranes
5. ulcerated lesions of the gums, tongue, lups and palate
6. cutaneous lesions spread to surrounding areas of the mouth and nose
Hint: yeast cells in a "steering wheel" formation
paracoccidiodes brasliensis
Opportunistic mycsoes are limited to people with ____.
Poor immunity
What are the five genera of of opportunistic fungi typically encountered?
1. Aspergillus
2. Candida
3. Cryptococcus
4. Pneumocystis
5. Mucor
Causative agent of aspergillosis?
Aspergillus
Aspergillus is found where?
soil, food, compost, agricultural buildings, air vents of homes, and offices worldwide
List the 3 clinical pulmonary diseases of aspergillus.
1. hypersensitivity aspergillus
2. noninvaasive aspergillus
3. acute invase pulmonary aspergillosis
Hypersensitivity aspergillosis manifests as:
asthma or other allergic symptoms
Noninvase aspergillomas are:
ball like masses of fungal hyphae - most cases are asymptomatic
Acute invasice pulmonary aspergillosis characteristics:
fever, cough, pain as present in pneumonia. Significant respiratory impairment can occur.
____ invasion of aspergillus in the skin via trauma or dissemination from the lungs,
cutaneous aspergillus
____ aspergillus involves major organ systems.
systemic
True or False

Immunolofical tests to detect angtigens in blood can be used to help confirm presence of aspergillus
True
Treatment of aspergillus hypersensitivity:
use of various allergy medications or desensitization to the allergen. also: amphotericin B and surgical removal of aspergillomas. Maintenance therapy with itraconazole is recommended wtih immunocompromised patients.
Causative agent of candidiasis:
Candida albicans
What opportunistic fungi can be transmitted between individuals?
candida
Which fungi has clusters of budding yeasts and pseudohyphae?
candida
Oral candidiasis in infants is treated with:
nystatin
vaginal candidiasis treatment:
azole suppositories/creams, and/or oral administration of fluconazole for vaginal candidiasis
Candidiasis of the fingernails?
onchomycosis
invasive candidiasis is treated with?
amphotericin B and often wtih 5-fluorocystine
___ is a basidomycete.
cryptococcus neoformans
2 strains of cryptococcus neoformans?
1. c. neoformans gattii

2. c. neoformans neoformans (worldwide)
How do you get cryptococcosis?
inhalation of bird poo spores
Unique characteristics of c. neoformans?
1. phagocytosis resistant capsule surrounding yeast form

2. produces melaning which inhibits phagocytosis

3. predilection for CNS which is isolated from the immune system by the blood brain barrier
Diseases of cryptococcus neoformans:
1. primary pulmonary cryptococcosis
2. invasive pulmonary cryptococcosis
3. Cryptococcal meningitis
4. Cryptococcoma (similiar to #3, but cause motor and neurological impairment)
5. Cutaneous cryptococcoma
Most common form of cryptococcal infection:
Cryptococcal meningitis

symptoms slow to develop -
headache, nauseua, vomitting, neck stiffness

later lost of vision and coma occur
Cryptococcoma: what and where
fungal masses in the cerebral hemispheres, cerebellus, and rarely in the spinal cord.
Confirmation of cryptococcal meningitis
detection of fungal antigens in CSF
Treatment for cryptococcoses
amphotericn b and 5-fluorocytosine together for 6 - 10 weeks
Causative agent of pneumocystis pneumonia
Pneumocystis jiroveci

opportunistic
Which fungi resembles a protozoa?
Pneumocystis jiroveci
Which fungi is an obligate parasite?
Pneumocystis jiroveci
Diagnosis of PCP?
Chest x ray and GMS

AND FLUORESCENT ANTIBODY
When you don't know how to diagnose?
Pick GMS
Treatment of PCP
trimethoprim and sulfanimide
also pentamidine is ok

(all antiprotozoan drugs)
Zygomycoses
1. Mucor
2. Rhizopus
3. Absidia
_____ are commonly seen in pateintes iwth uncontrolled diabtes, in people who inject illegal drugs, cancer patients, and in some patients receiving antimicrobial agents.
zygomycoses
4 conditions of zygomycoses
1. Rhinocerebral zygomycosis
2. Pulmonary zygomycosis
3. Gastrointestinal zygomycosis
4. Cutaneous zygomycosis
Rhinocerebral zygomycosis
infection of paranasal sinuses that spreads to foof of the mouth (COTTON LIKE GROWTHS) subsequently invades blood vessels where it produces fibrous clots that can cause tissue necrosis
Pulonary zygomycosis
deep inhalation of spores like from moledy foods into brnchioles and alveoli

kills lung tissue
Gastrointestinal zygomycosis
Ulcers in intestinal tract after ingestion
Cutaneous zygomycosis
introduction in skin after trauma. Lesions range from pustules and ulcers to abcesses and dead patches of skin
Diagnosis of zygomycoses
patient history and microscopic samples. KOH mounts and GMS stains (show irregular branching and few septate divisions)
Treatment of Zygomycoses
physical curettage and IV amphotericin B for 8 - 10 weeks
3 mycoses common in AIDS victims?
Candida albicans, aspergillus fumigatus, and cryptococcus neoformans
Why so many funal opportunists appering?
1. Growing number of immunocompromised individuals (AIDS)

2.Widespread use of antifungal drugs leads to resistant strains
New fungal opportunists?
fusarium spp. & oebucukkuyn narbeffeu --> ascomycetes

trichosporon beigelii --> basidiomycete
Which fungal opportunists is resistant to amphotericin B?
Fusarium spp
Which new fungal opportunist causes respiratory distress?
fusarium
Which new fungal opportunist causes pulmonary distress?
penicellium marneffei
___ mycoses are usually acquired by direct contact and are the most common fungal infections.
Superficial
Primary food of superificial fungi?
keratin
Superficial infection(s)?
Black and White Piedra
____ is a superficial infection that forms nodules on hair shafts.
Piedra - don't share hairbrushes! yuk
Causative agent of black piedra and where?
Piedaia hortae

central and south america and southeast asia
causative agent of white piedra and where?
trichosporon beigelii

worldwide in the tropics and subtropics
TX for Piedra?
shaving the head or antifungal agents like terbinafine
..used to be called ringworm...
dermatophytes
dermatophytes grow only on...
skin, nails, and hair
medical name for dermatophytoses
tinea
dermatophytes provoke ____ which _____.
cell mediated immune response
tissue damage
What 3 genera of ascomycetes are responsible for dermatophytoses?

which species affect hair?
1. Trichophyton
2. microsporum
3. epidermophyton floccosum

trichophyton affects hair
Athelets foot

agents
Tinea pedis

Trichophytop rubrum
t. mentagrophytes var. interdigitale
Epidermophyton floccosum
Jock itch
tinea cruris

Trichophytop rubrum
t. mentagrophytes var. interdigitale
Epidermophyton floccosum
Onchomycosis
Tinea unguium

Trichophytop rubrum
t. mentagrophytes var. interdigitale
What confirms a diagnosis of dermatophytoses?
presence of arthroconidia
TX of dermatophytoses
1. topical or antifungal agents

2. if widespread, terbinafine 6-12 weeks

3. Stubborn- griseofulvin until cured
___ is a basidiomycete that, when chronically infected, causes pityriasis.
Malasseziafurfur
_____ is characterized by depigmented or hyperpigmented patches of scaly skin.
Pityriasis
Pityriasis is AKA
TINEA VERSICOLOR
M.furfur causes what else besides tinea versicolor?
folliculitis, seborrheic dermatitis, and dandruff
What's tje quickest way to diagnose m.furfur infections?
Stick patient under a UV light

also budding yeasts and short hyphal forms
TX for superficial malassezia
topically with imidazoles like ketoconazole shampoos

also lotions with zinc pyrithione, selenium sulfide lotions, or propylene glycole solutions
___ are involved in cutaneous and subcutaneous mycoses.
common soil saprobes
Examples of cutaneous and subcutaneous fungi
chromoblastomycosis and phaeohyphomycosis
chromoblastomycosis and phaeohyphomycosis are caused by
dematiaceous fungi
What 4 fungi cause chromoblastomycosis?
phialophor verrucosa, fonsecaea pedrosoi, f. compacta, and cladophialophora carrionii
which ascomycetes cause phaeohyphomycosis?
alternaria, exophiala, wangiella, and cladophialophora
chromoblastomycosis features
small itchy, but painless scaly lesions on skin

several years later lesions thicken, become flat and large

then you get inflammation, fibrosis and abcess formation near surrounding tissues

may spread to rest of the body
phaeohyphomycoses types
paranasal sinus phaeohyphomycoses

cerebral phaeohyphomycosis (caused by cladophilophora bantiana)<-- rarest but deadliest
How to distinguish b/t chromoblastomycosis and phaeohyphomycosis
c's have golden brown sclerotic bodies, p's have brown pigmetnted hyphae
TX for phaeohyphomycoses
itraconazole, but permanently destructive to tissue
TX for chomoblastomycosis
surgical removal of infected and surrounding tissues (amputation may be necessary) Thiabendazole and 5-fluorocytosine 3-12 months
what to do to avoid dematiaceous infections
Wear shoes
What is a fungal mycetoma?
tumorlike infection of the skin, fascia, and bones of hand or feet caused by mycelial fungi of several gernera in the division ascomycota: madurella, pseudallescheria, exophiala, and acremonium
Cases of fungal mycetoma in US mostly likely caused by
pseudallescheria or exophiala
mycetoma infection
live in soil, get in body by prick wounds and scrapes by twigs, thorns, or leaves contaminated with fungi

Ugly black foot
tx of mycetoma infection
surgival removal of mycetoma and 1-3 years of antifungal therapy with ketoconazole
Rose gardener's disease
Sporotrichosis
Causative agent of sporotichosis
sporothrix schenckii
Sporotrichosis limited to
arms and legs since s. schenckii resides in soil
Fixed cutaneous sporotirichosis lesions become
puss filled
if sporotrichosis affects lymphatic system
lymphocutaneous sporotrichosis
TX of sporotrichosis
topical applications of saturated potassium iodide for several months.
What are the two types of toxicosis?
Mycotoxicosis
mycetismus
define mycotoxicoses
caused by eating food contaiminated with fungal toxins
define mycetismus
mushroom poisoning resulting from eating the fungus
fungi can produce ______, chemicals that are poisonous to animals and humans
mycotoxins
Long-term ingestion of mycotoxins can cause what complications?
Liver and kidney damage, GI or gynecological distrubances or cancers
_____ are toxins produced by Aspergillus.
Aflatoxins
Aflatoxins can cause
liver damage and liver cancer throughout the world, but is most prevalent in tropics
List some useful mycotoxins
Claviceps ppurpurea - used in drugs

ergometrine - stimulates labor contractions
Poisonous mushrooms are commonly called
toadstools
The deadliest mushroom toxin is produced by the:
"death cap" mushroom
Death cap mushroom species
amanita phalloids
List the two toxins in the death cap mushroom and their function
phalloidin- irrecersibly binds actin in cells and disrupting cell structure

alpha-amanitin- inhibits mRNA synthesis

both toxins cause liver damage
This mushroom causes bloody diarhhea, convulsions, and death within 2 days after ingestion
Gyromitra Esculenta, the false morel
This mushroom causes excessive thirst, nausea, and kidney failure between 3 days and 3 weeks after ingestion.
Cortinarius gentilis
hallucinogenic toxins of psilocybe cubensis and amanita muscaria are:
ibotenic acid and muscimol
TX of mushroom poisoning
vomit
oral administration of activated charcol
possible liver transplant
Fungal allergies typically cause _____ in which immunoglobin ___ binds the allergin.
Type I hypersensitivity

E