Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
86 Cards in this Set
- Front
- Back
|
What are the two major forms fungi? Distinguish between them
|
Yeast - single cell, reproduce by budding, rigid cell wall
Mold - branching filaments = hyphae, form mycelium |
|
|
What does dimorphic mean in regards to mycology
|
The species is in a yeast form at body temperature/in body tissues and in a mold form in culture at ambient temperatures
|
|
|
What is the principal means by which filamentous fungi (molds) reproduce
|
Sporulation
|
|
|
What is Saboraud dextrose agar used for, what is significant about it?
|
Growing fungi, low pH inhibits bacterial growth
|
|
|
Describe the growth media used during laboratory identification of fungi
|
Low pH, may contain antibiotics, goal is to allow fungal growth and limit bacterial growth
|
|
|
What are cutaneous mycoses also known as
|
Dermatophytes
|
|
|
What are the three species of cutaneous mycoses that we should be aware of
|
Trichophyton, Epidermophyton, Microsporum
|
|
|
What do cutaneous mycoses cause infection of
|
hair, skin, nails
|
|
|
How are cutaneous mycoses most often transmitted
|
Infected skin scales, so, either human-human or animal-human
|
|
|
What is the source of nutrition for dermatophytes
|
keratin
|
|
|
Do dermatophytes invade nonkeratinized tissues
|
No
|
|
|
What locations does Trichophyton infect
|
Hair skin nails
|
|
|
What locations does Microsporum infect
|
Hair skin
|
|
|
What locations does Epidermophyton infect
|
skin nails
|
|
|
A dermatophyte that infects skin, hair, and nails
|
Trichophyton
|
|
|
A dermatophyte that infects skin and hair (but not nails)
|
Microsporum
|
|
|
A dermatophyte that infects skin and nails (but not hair)
|
Epidermophyton
|
|
|
Athlete's foot is caused by what organism
|
Tinea pedis
|
|
|
An organism causing ?a rash? ?petichiae? in a rounded pattern with an outer ring
|
Tinea corporis (Ringworm)
|
|
|
Scalp "ringworm" is caused by what organism
|
Tinea capitis
|
|
|
"Jock itch" is caused by what organism
|
Tinea cruris
|
|
|
Onychomycosis is caused by what organism (nail-bed)
|
Tinea unguium
|
|
|
Subcutaneous mycoses infect what
|
Dermis, subcutaneous tissue, and bone
|
|
|
Organisms causing subcutaneous mycoses usually come from where and are transmitted how?
|
Organisms reside in soil and decaying or live vegetation, usually acquired through traumatic lacerations or puncture wounds
|
|
|
What is a common subcutaneous mycoses in the US causing granulomatous leasions at puncture site with possible secondary lesions along draining lymphatics
|
Sporotrichosis
|
|
|
Sporotrichosis will present with what
|
Granulomatous lesions with secondary lesions along draining lymphatics
|
|
|
Is sporotrichosis dimorphic
|
Yes
|
|
|
What is an identifying characteristic of Sporotricosis organisms grown in a lab culture
|
"Flowerette" arrangements
|
|
|
What subcutaneous mycoses are common in the United States
|
Sporotrichosis
|
|
|
Describe chromomycosis
|
Crusty, warty nodules spreading along lymphatics
|
|
|
What is the usual cause of chromomycosis
|
"Dematiaceous" (pigmented) fungi
|
|
|
Describe mycetoma
|
Localized abscesses usually on feet, discharge pus, serum and blood through "sinuses" (abnormal channels), can spread to bone, DEFINING CHARACTERISTIC: Presence of colored grains
|
|
|
What are the true pathogenic organisms causing systemic mycoses
|
Coccidiodomycosis, Histoplasmosis, Blastomycosis, Paracoccidiomycosis
|
|
|
What are the opportunistic pathogens causing systemic mycoses
|
Cadidiasis, Cryptococcosis, Aspergillosis, Mucormycocis, Pneumocystis juroveci
|
|
|
Is coccidiodomycosis dimorphic
|
Yes
|
|
|
Is histoplasmosis dimorphic
|
Yes
|
|
|
Is blastomycosis dimorphic
|
Yes
|
|
|
Is Paracoccidiomycosis dimorphic
|
Yes
|
|
|
Is candidiasis dimorphic
|
No
|
|
|
Is cryptococcosis dimorphic
|
No
|
|
|
Is Aspergillosis dimorphic
|
No
|
|
|
Is Mucormycocis dimorphic
|
No
|
|
|
Is Pneumocystis juroveci dimorphic
|
No
|
|
|
How do many dimorphic fungi gain access to the body
|
Inhalation of airborne spores, spores germinate in lung
|
|
|
Describe the various pathologies associated with inhaled dimorphic fungi
|
Asymptomatic primary pulmonary infection - common
Acute pulmonary disease - less common Cronic Pulmonary or disseminated infection - rare |
|
|
Coccidiodomycosis is caused by what organism
|
Coccidiodes immitis
|
|
|
What region of the united states has a high prevalence of coccidiodomycosis
|
South West
|
|
|
What are arthrospores
|
Barrel-shaped spore
|
|
|
What is the culture form of Coccidiodes and what is its tissue form
|
Culture - Arthrospores, Tissue - Spherules
|
|
|
How is coccidiomycosis diagnosed/identified in the lab
|
Culture, histopathology, serology, DNA probe
|
|
|
What organism causes histoplasmosis
|
Histoplasma capsulatum
|
|
|
What regions of the US have higher prevalence of Histoplasmosis
|
Ohio and Mississippi River Valleys
|
|
|
A chiroptologist (person who studies bats) presents with yeast cells growing within macrophages, what is the organism likely to be
|
Histoplasma capsulatum
|
|
|
What are the major identifying characteristics of Histoplasma in the lab
|
can multiply in macrophages
Hallmark of this is intracellular parasitism |
|
|
What organism causes Blastomycosis
|
Blastomyces dematitidis
|
|
|
Blastomyces pathogenesis is similar to what organism
|
Histoplasma
|
|
|
How is a blastomyces infection acquired
|
Inhalation of spores
|
|
|
How does Blastomyces appear on a Gram stain
|
Gram negative, thick wall
|
|
|
What organism causes paracoccidiodomycosis
|
Paracoccidiodes brasilensis
|
|
|
What is another name for Paracoccidiodomycosis
|
South American blastomycosis
|
|
|
What is a major endemic dimorphic fungus in Latin America
|
Paracoccidiodes
|
|
|
How does paracoccidiodomycosis differ from histo and blasto
|
Same, except most common secondary site of infection is mucosa of mouth and nose
|
|
|
90% of paracoccidiodomycosis infections occur in what group of people
|
males
|
|
|
What does Paracoccidiodes look like when cultured at 37C
|
Pilot or Mariner's wheel (Large center bud with spoke like buds extending from it)
|
|
|
Why is Candida albicans not considered dimorphic
|
Yeast and hyphal forms can be seen at same time at same temp
|
|
|
What is the most common species of organism causing Candidiasis
|
Candida albicans
|
|
|
Candida albicans is natural flora of what
|
skin, mucous membranes, GI and GU tracts
|
|
|
The majority of Cadidiasis infections are exogenous/endogenous?
|
Endogenous (we infect ourselves)
|
|
|
What are the sites of infection of a systemic cadidiasis
|
Just about everywhere
|
|
|
Systemic candidiasis occurs most often in what populations
|
Immunosuppressed, cancer patients, patients on antibiotic therapy
|
|
|
What is the mainstay of diagnosis for candidiasis
|
Culture
|
|
|
What is Cryptococcocis caused by
|
Cryptococcus neoformans, YEAST form
|
|
|
Where is Cryptococcus neoformans found in nature
|
Worldwide, Particularly in soil with bird/pigeon droppings
|
|
|
What is the most common clinical manifestation of cryptococcocis and what is a risk for immunocompromised
|
Mild lung infection. Could spread to brain and meninges
|
|
|
How would you identify Cryptococcus on a slide
|
India ink, large capsule around yeast bud
|
|
|
What causes aspergillosis
|
several species of filamentous fungus, Aspergillus
|
|
|
Where is Aspergillus found
|
Soil, dust, decomposing organic matter
|
|
|
What are the superficial/colonizing syndromes of aspergillosis
|
Otomycosis (ear), Onchomycosis (nail), Keratitis (?eye?)
|
|
|
What are the invasive infections of aspergillosis
|
Invasive: pulmonary (could cause angioinvasion), sinusitis, disseminated (high fatality rate, difficult to treat)
|
|
|
What are the allergic related manifestations of aspergillosis
|
Allergic sinusitis: local eosinophilia. Allergic bronchopulmonary aspergillosis Long-term allergic response, elevated specific IgE, systemic eosinophilia, immediate response to skin prick. Aspergilloma (fungus ball)
|
|
|
What are some diagnostic tests for aspergillus
|
Direct examination of tissue (granulomas and radiating chains of septate hyphae), culture, detection of aspergillus galactomannan antigen in serum
|
|
|
What is a major characteristic to remember about the organism causing mucormycosis
|
Non-septate fungi
|
|
|
Is mucormycosis angioinvasive
|
Yes, like aspergillus
|
|
|
List the types of mucormycosis
|
Rhinocerebral (rapidly fatal, surgical intervention), Pulmonary, Cutaneous, Gastrointestinal
|
|
|
What group of people will most often be seen with Pneumocystis jurovecii
|
HIV+
|
|
|
What is a hallmark of Pneumocystis jurovecii associated pneumonia
|
Hypoxemia
|
