MICRO Exam 3

How can males get candida infections on their penis? What is this called?

Sex w/ someone who has Candida vaginitis. Balanitis

How does erythematous candidiasis appear? What pts. are most likely to have this?

Red, inflamed areas of varying size. NO curd-like patches. Seen commonly in denture pts.

*(Candida/Aspergillus)* is acquired from an endogenous source

Candida

Which genus is the most common cause of ALL fungal infections?

Candida (opportunistic overgrowth)

What species is the most common cause of invasive candidiasis?

Candida albicans

Which emerging Candida species is associated w/ high mortality and resistance to anti-fungals?

Candida auris

Dermatophyte infection of the scalp is tinea ________

Capitis

Neutralizing antibodies bind to what portion of a naked virus?

Capsid proteins

What types of cancers can HPV cause? (3)

Cervical, anal and oropharyngeal

*(Thrush/Chronic Hyperplastic Leukoplakia)* results in white lesions that ARE NOT easily wiped off.

Chronic hyperplastic leukoplakia

When are dimorphic fungi found in a mold form?

"Mold in the cold" ~25C, poor nutrients

When are dimorphic fungi found in a yeast form?

"Yeast in the heat" ~37 C, rich nutrients

Aspergillus has hyphae with extensive branching @ a *(45/90)* degree angle

45

Rhizopus has hyphae with extensive branching @ a *(45/90)* degree angle

90

How can C. albicans be differentiated from other Candida spp?

Formation of germ tube

What type of cancer can HTLV cause?

Adult T-cell leukemia and lymphoma

Fungal pathogens typically grow *(aerobically/anaerobically)*

Aerobically

Saprophytic definition

Aid in decomposition & recycling of C and N from dead organic matter

What is the most common pathology associated w/ exposure to fungal spores?

Allergic reactions

Which type of candidiasis is often seen as a complication of thrush of erythematous? How does this appear?

Angular chelitis Red/inflamed/ulcerated/crusted sores @ the corner of the mouth

*(Asexual/sexual)* reproduction is observed in most of the pathogenic fungi

Asexual. (sexual reproduction is RARELY seen clinically)

*(Candida/Aspergillus)* is acquired from an exogenous source

Aspergillus

What is the most commonly encountered mold outdoors?

Aspergillus

Which fungus is the 2nd leading cause of opportunistic fungal infections?

Aspergillus

Which Aspergillus spp. is the most virulent and most commonly encountered?

Aspergillus funmigatis

What makes up a majority of fungal cell wall and is the major immuno-stimulant?

B-glucan polymers

What is the gold standard agar used for culturing Candida?

Blood agar (very slow culture)

*(Naked/Enveloped)* viruses are able to be endocytosed by host cells

Both

Microsporum spp. grow in *(macroconidia/microconidia/both)*

Both. Macroconidia are spindle-shaped

Trichophyton spp. grow in *(macroconidia/microconidia/both)*

Both. Prominent microconidia. Cigar-shaped macroconidida

What type of cancers can EBV cause? (2)

Burkitt lymphoma Nasopharyngeal carcinoma

Secondary receptors for HIV

CCR5 or CXCR4 CCR5 is the ONLY receptor during initial infection. Ppl lacking this receptor are mostly protected from HIV.

Primary receptor for HIV

CD4

What are spores produced by molds called?

Conidia/conidiospores

How does Thrush appear?

Cream-colored, curd-like white pathches that are *easily removed w/ bleeding underneath*

*(Lytic/Cytophathic)* viruses kill the host cell, but NOT as part of their life cycle

Cytopathic

Fungal spores are resistant to *(heat/drying/both)*

Drying only. Not resistant to heat like bacterial spores

Which viruses are able to cause cancer? (6)

EBV HPV HHV-8 HTLV HBV HCV

Neutralizing antibodies bind to what portion of an enveloped virus?

Envelope glycoproteins embedded in lipid bilayer

*(naked/enveloped)* viruses are more fragile

Enveloped

Helical capsid containing human viruses are *(naked/enveloped)*

Enveloped

*(Naked/enveloped)* viruses are able to merge with the cell membrane of a host cell

Enveloped only

What are the 3 genera of dermatophytes?

Epidermophyton Microsporum Ttrichophyton

What is the primary target for anti-fungal medications? Where is this found?

Ergosterol Replaces cholesterol in plasma membranes of fungi

Fungi are *(prokaryotic/eukaryotic)*

Eukaryotic

What type of cancer can HBV and HCV cause?

Hepatocellular carcinoma

Which fungal group is inherently virulent and capable of causing diseases in normal individuals?

Histoplasma

Which fungal group is typically transmitted through bat/bird feces?

Histoplasma

Which 2 species are dimorphic fungi?h

Histoplasma (true) Candida (variable)

Which fungal spp is endemic in the Ohio & Mississippi valley?

Histoplasma capsulatum

Most common endemic fungal infection in US

Histoplasmosis

Individual filaments of mold are known as *(hyphae/mycelium)*

Hyphae

All RNA viruses are *(helical/icosahedral)* Are there any exceptions?

Icosahedral -ssRNA viruses are helical

All DNA viruses are *(helical/icosahedral)* Are there any exceptions?

Icosahedral No exceptions.

Aspergillus grows as a *(yeast/mold/both)*

ONLY a filamentous mold

What are viral envelopes derived from?

Infected cell membrane

What is a candida infection found in folds of skin called?

Intertrigo

What type of cancer can HHV-8 cause?

Kaposi's sarcoma (in HIV infection)

What is the major virulence protein secreted by dermatophytes that results in degradation of hair, skin and nails?

Keratinase

How does chronic hyperplastic leukoplakia appear clinically?

Lesions on oral mucosa of cheek, angles of mouth or tongue. *White patches CANNOT be rubbed off.*

Most helical capsids have a *(loose/rigid)* structure

Loose

*(Lytic/Cytophathic)* viruses kill the host cell as part of their life cycle

Lytic

Epidermophyton spp. grow in *(macroconidia/microconidia/both)*

Macroconidia. (club-shaped) NO microconidia

Icosahedral capsid containing human viruses are *(naked/enveloped)*

May be either

*(yeast/mold)* grows in a filamentous form

Mold

Dermatophytes grow as a *(yeast/mold/both)*

Mold only

*(yeasts/molds)* are multi-celled

Molds

Masses of filaments of mold are known as *(hyphae/mycelium)*

Mycelium

*(naked/enveloped)* viruses are more resistant to detergents, heat, drying, etc.

Naked

How can Aspergillosis manifest in the oral cavity?

Necrotic ulceration of the hard palate due to Aspergillosis in the nasal cavity

What component of the immune system prevents viruses from infecting cells?

Neutralizing antibodies

Candida infections of nails is called... What pts. are at a higher risk for this?

Onychomycosis (5% of nail infections) Diabetes = risk factor

Which form of candidiasis is called Thrush?

Pseudomembranous

How can oral candidiasis manifest? (4)

Pseudomembranous (Thrush) Erythematous Angular cheilitis Chronic hyperplastic (leukoplakia)

Aspergillus grows as a mold with *(septae/non-septae)* hyphae

Septae

Dermatophytes grow as a *(septae/non-septae)* mold

Septae

Primary receptor for influenza

Sialic acid

What is it called when a virus causes an infected cell to fuse membranes w/ a neighboring cell, resulting in a large multi-nucleated cells?

Syncytium

*(Thrush/Chronic Hyperplastic Leukoplakia)* results in white lesions that ARE easily wiped off.

Thrush

Which dermatophyte infections present similarly to ringworm in appearance?

Tinea corporis (trunk, arms, legs)

How are Candida infections typically acquired?

Typically, from one's own normal flora. May also get from catheters, prosthetic devices, etc.

Fungal spores are produced in *(favorable/unfavorable)* environments.

Unfavorable

Fungal cell walls contain *(cellulose/peptidoglycan/polysaccharides)*

Various immuno-stimulating polysaccharides NO cellulose or peptidoglycan

Predisposing factors for Candida infection. (8) *very important to know*

Very young/old HIV/AIDS Malignancy, cytotoxic therapies Antibiotic therapy Prostheses Dentures Diabetes Sjogrens syndrome (xeroxtomia)

What is tropism?

What type of cell a virus can infect is based on the receptor the virus has

*(yeasts/molds)* are single celled

Yeasts

Is Candida normal flora? If so, where?

Yes. URT, skin, GI, vagina

Which fungal group has hyphae that *lack septations* (non-septae)

Zygomycetes (Rhizopus is a spp. in this group)

Infection of the nose, eye, sinuses and brain that results in *black coloration of the skin* is commonly caused by what fungal agent?

Zygomycetes (Rhizopus)

Which fungal group has a tendency to invade major blood vessels, leading to black pus?

Zygomycoses (Rhizopus)

How do yeasts reproduce?

asexually by budding

Dermatophyte infection of the facial hair is tinea ________

barbae

Dermatophyte infection of the trunk is tinea ________

corporis

Dermatophyte infection of the groin is tinea ________

cruris

Dermatophyte infection of the face is tinea ________

faciei

Dermatophyte infection of the hands is tinea ________

manuum

Fungi that are associated with plant roots are called...

mycorrhizae

Rhizopus grows as a mold with *(septae/non-septae)* hyphae

non-septae

Dermatophyte infection of the feet is tinea ________

pedis

Dermatophyte infection of the nails is tinea ________

unguium