MYCO & VIROLOGY L3 (Midterms- Opportunistic and Systemic) Flashcards
(119 cards)
1
Q
Seen in immunocompromised patients.
Commonly encountered as saprobes
A
Opportunistic mycoses
2
Q
One of the most commonly encountered fungi in the lab (common in peanuts)
A
Aspergillus spp.
3
Q
- Second most isolated fungus after Candida spp.
- Widespread in the environment
- Conidia are easily dispersed in the environment
A
Aspergillus spp.
4
Q
Aspergillus spp. are transmitted by?
A
Inhalation
5
Q
Aspergillus spp. septate hyphae branches out at _____ degrees?
A
45
6
Q
In the _________, conidia of aspergillus spp. germinate and invade the tissue
A
lung air spaces
7
Q
IDENTIFY based on clinical manifestations:
- Pulmonary or sinus fungus balls
- Allergic bronchopulmonary aspergillosis
- External otomycosis (auditory canal)
- Mycotic keratitis
- Onychomycosis (nail and surrounding tissues)
- Sinusitis
- Endocarditis
A
Aspergillus spp.
8
Q
In terms of structure, aspergillus has a _______
hyphae and conidiophore. And if you look closely, they have a vesicle at the end of the condiophore, these vesicles have ________ attached to them
A
septated; mutulae
9
Q
Its other characteristics include an erect conidiophore arising from a foot cell within the vegetative hyphae
A
Aspergillus spp.
9
Q
A supporting structure where the phialides attached.
A
Metulae
9
Q
Conidia of aspergillus spp. are produced from the?
A
phialides
10
Q
What makes this unique is that it has a metula/metulae before the phialide
A
Aspergillus spp.
10
Q
Laboratory dx for aspergillus spp.
A
- Antigen-protein based assays
- Nucleic Acid Amplification Assay
11
Q
What is the downside of Antigen-protein based assays?
A
not true to all species of Aspergillus because it can have cross reactions
11
Q
This organism has a fungus ball
A
Aspergillus spp.
12
Q
This assay is used for monitoring patients who are at high risk ofdeveloping invasive fungal infections
A
Antigen-protein based assays
13
Q
What is the downside of Nucleic Acid Amplification Assay?
A
not readily available for fungi in general
14
Q
Enumerate the different species of aspergillus
A
- A. fumigatus
- A. flavus
- A. niger
15
Q
When cultured it rapidly grows (1-5 days) and manifests a yellow-green colony
A
Aspergillus flavus
16
Q
Microscopically, its phialides give rise to short chains of yellow orange elliptical or spherical conidia
A
A. flavus
17
Q
Produced directly from the vesicle
A
Uniseriate
18
Q
Produced from a primary row of cells called metulae
A
Biseriate
19
Q
Macroscopically, it produces darkly pigmented, roughened spores
A
A. niger
20
Q
Microscopically, its hyphae are hyaline and septate
A
A. niger
21
Aspergillus niger's colony **mature within**?
2-6 days
22
**Young colony** of A. niger appears?
yellow
23
Its appears **black dotted surface** due to conidia
Old colony of A. niger
24
Remains **buff** or **cream** **colored**
reverse colony of A. niger
25
IDENTIFY based on structure:
- Septate hyphae
- **Long** condiophores
- **Large metulae**
- Smaller phialides (**biseriate**)
A. niger
26
These can also be **commonly seen in clinical laboratory** but its association with the clinical disease that it can cause is **still unclear**.
A. niger
26
A. niger is known to cause?
fungus ball and
otitis externa
26
It is a ***rapid grower*** (2-6 days), has **blue-green appearance** and is **thermotolerant at 45C**
A. fumigatus
27
IDENTIFY based on microscopic characteristics:
- Septate hyphae
- **“foot cell”** at base ***-L or T-shaped***
A. fumigatus
28
Differentiate the different species of Aspergillus based on their **rate of growth.**
A. fumigatus: rapid grower; 2-6 days
A. flavus: rapid grower; 1-5 days
A. niger: rapid grower; 2-6 days
29
Common *environmental* isolates **associated with soil and plants**
Mucorales
30
They contaminate **grains, breads, and fruits** and are most often associated with **infections** of the ***sinuses, lungs, and skin*** of immunocompromised patients
Mucorales
31
IDENTIFY based on general microscopic characteristics:
- **Saclike fruiting structures** (sporangia)
- Sporangium is formed at tip of sporangiophore
- Septate hyphae
- **Rootlike structure**
Mucorales
32
What do you call the **septate hyphae** of mucorales?
stolon
33
The **rootlike structure** of mucorales is called?
rhizoids
34
Agents of Mucorales
- Cunninghamella
- Lichtheimia
- Mucor
- Rhizopus
35
**Central axis of the sporangia**
(multispored structure)
columella (singular)
36
**Swelling** of the sporangiophore below the columellae (plural)
Apophysis
37
Some species (of mucorales) also produce _____ that hold the sporangiophore within the **soil or growth substrate**. Which are then connected to a branching root, or ______
rhizoids; stolon
38
These attach at contact points where **rootlike structures** (rhizoids) may appear and **anchor** the organism to the agar surface
Stolons
39
Marked propensity for **vascular invasion**. Rapidly produce **thrombosis** and **necrosis** of tissue
Mucormycosis
40
**Common presentation** of mucomycosis
Rhinocerebral form
41
Potential means of **retroorbital spread** (i.e., invasion into the brain)
Perineural invasion
42
Specimens used for Mucorales testing/identification
- Deep tissue or lesion sample
- Nasal discharge or scrapings
- Respiratory samples
42
Specimens tested for mucorales should be transported within how many hours upon collection?
2 hours
43
TRUE OR FALSE: Mucorales are not sensitive to environmental changes
FALSE. **Mucorales are sensitive**
43
***Blood cultures are not ideal*** for this type of fungi
Mucorales
44
Stains used for dectecting/testing for presence of mucorales
Calcoflour white and KOH
45
Molecular methods used for dectecting/testing for presence of mucorales
- Nucleic acid testing
- Polymerase chain reaction (PCR) Amplificat
46
Agars used for **cultivating mucorales**
- Potato dextrose
- 2% Malt
- Cherry decoction (acidic) agar
47
These contain *high concentrations* of ***carbohydrates*** that **inhibits** the production of **asexual fruiting bodies** that are required for the proper identification of the **Mucorales species**
Growth media
48
IDENTIFY based on morphological colonial characteristics:
- **fluffy, white to gray or brown**
- Hyphae diffusely covers the surface of the agar within **24 to 96 hours**
- Rapid grower of hyphae
- **“lid lifter”**
Mucorales
48
Reproduction characteristics of Mucorales
sexually: zygospores
asexually: sporangiospores
49
IDENTIFY based on microscopic apperance:
- **Erect** sporangiophores
- **Few septate**
- **Internodal rhizoids** (short, thin projections that anchor the growing cells)
Lichtheimia
49
IDENTIFY:
-Can be recovered from the **sinuses**
- Sporangiophores
- Erect
- branching into **several vesicles** that bear
sporangioles
- ***White to gray cottony colony***
Cunninghamela
50
IDENTIFY:
- Agent for **rhinocerebral mucormycosis**
- found in patients with **diabetes** and **ketoacidosis**
Lichtheimia
51
Its hyphae are **broad** and **ribbon-like**
Lichtheimia
52
**Agent** of disseminated disease
Mucor
53
**Rhizoids are absent**. Its sporangia remain **intact**
Mucor
54
Colony characteristics of Mucorales
Dirty white-mousy brown colonies
55
IDENTIFY:
- **Most common Mucorale**s causing human disease
- May be **recovered** from **almost any source**
- Rhizoids appear **opposite of stolon**
- Rapid grower
- **erect sporangiophores** terminating in dark sporangia and sporangiospores
Rhizopus
56
Slide culture preparations shows **“umbrella-shaped”**
Rhizopus
57
Enumerate the different species of Mucorales
- Cunninghamella
- Lichtheimia
- Mucor
- Rhizopus
58
**Pulmonary disease** in immunocompromised
patients
Geotrichum
59
Microscopically, its **arthroconidia** formed from **vegetative hyphae** and occur **singly or may be branched**
Geotrichum
60
Colonies appear **white to cream** and **yeastlike** and ***can be confused with Trichosporon spp***. Septate and hyaline saprophyte
Geotrichum
61
IDENTIFY:
- Inhibited at 37°C
- **rarely cause infections**
- disease involve **chronic fungal sinusitis**
- Septate and hyaline saprophytes
Pencillium
62
Microscopically, its conidiophores are **erect**, sometimes branched, and metulae bearing one or several phialides on which oval to ovoid conidia are **produced in long, loose chains**
Pencillium
63
Its a rapid grower, with colonies usually in shades of **green or blue-green**
Pencillium
64
IDENTIFY:
- **share several characteristics** with opportunistic fungi
- Any opportunistics fungal agent **has the capacity to disseminate to sites**
- Generally **shows dimorphism**
22C - fungi
35-37C -Yeast
Systemic mycoses
65
Most **prevalent in middle-aged men** as are other systemic mycoses, presumably because **occupational** and **recreational exposure to soil** is often greater among men
Blastomyces dermatitidis
66
May exhibit **flulike symptoms** but *most often* are **asymptomatic**
Blastomyces dermatitidis
67
Also known as **Gilchrist disease, North American blastomycosis**, and **Chicago disease**. It occurs primarily in *North America and parts of Africa*.
Blastomyces dermatitidis
68
What are the two species of Blastomyces?
- Blastomyces dermatitis and Blastomyces gilchristii
69
***Macroscopically***, it shows slow to moderate growth. White to dark tan, Young colonies is **tenacious**, older colonies **glabrous to woolly**
Blastomyces
dermatitidis at
22C (mold form)
70
Culture media & temperature for **Blastomyces
dermatitidis (yeast form)**
Blood agar 37C
71
***Microscopically***, it appears **oval**, **pyriform** to **globose** smooth conidia borne on short, lateral hyphalike conidiophores
Blastomyces dermatitidis at 22C (mold form)
72
Large yeast (8-12 um). Blastoconidia attached
by **broad base**
Blastomyces dermatitidis (yeast form)
73
Acquired by the **inhalation** of the **microconidia**
Histoplasma capsulatum
74
IDENTIFY:
- Microconidia are **phagocytized** by macrophages in the pulmonary parenchyma
- **Usually asymptomatic** in intact immune defenses
- **Calcification** may appear in the lungs, liver, and spleen
Histoplasma capsulatum
75
Associated with **reticuloendothelial** **cytomycosis**, “**cave disease”, spelunker’s disease, and Darling disease**
Histoplasma capsulatum
76
This organism **resides in soil with a high nitrogen content**, particularly in areas ***heavily contaminated*** with **bat** and **bird guano**
Histoplasma capsulatum
77
Lab dx for Histoplasma capsulatum
Enzyme immune assay methods
78
Enzyme immune assay methods can be performed on:
- Serum, CSF, and Urine
79
***Macroscopically***, it is characterized by **slow growth**, appears **white to dark tan** with age, and wholly, cottony, or granular
Histoplasma
capsulatum at 22C
(mold form)
80
Microscopically, its **microconidia** are small, one- celled, round, smooth (2-5 um), its **tuberculated macroconidia** are large, round (7- 12 um), and has **hyphalike** conidiophores
Histoplasma
capsulatum at
22C
(mold form)
81
IDENTIFY: ***Small, oval, yeast*** (**2-5 um**)
Yeast form of Histoplasma
capsulatum
82
Culture media and temperature utilized for cultivating **Histoplasma capsulatum** **(yeast form)**
Pines medium, glucose-cysteine blood, or BHI agar-blood, 37C
83
IDENTIFY:
- Primary route is **pulmonary**
- Formation of **ulcerative granulomatous lesions** of the buccal, nasal, and occasionally gastrointestinal mucosa
- ***narrow range of temperature tolerance***
Paracoccidiodes brasilensis
84
This organism **often likes cooler areas of the body**
Paracoccidiodes brasilensis
85
Disease associated with Paracoccidiodes brasilensis
Paracoccidioidomycosis
and Lutz-Splendore-Almeida disease
86
Colonies frequently ***only* produce sterile
hyphae**
Paracoccidiodes brasilensis
87
**Fresh isolates** may produce conidia **similar** to those of ***B dermatitidis***
Paracoccidiodes brasilensis
88
Macroscopically, it is characterized by ***slow growth***.
**White to beige**, and colony is **glabrous,leathery, flat to wrinkled, and folded or velvety**
Paracoccidiodes brasilensis
89
IDENTIFY:
**Multiple blastoconidia budding** from ***single, large yeast*** (**15-30 um**)
Paracoccidiodes brasilensis (yeast form)
89
Paracoccidiodes brasilensis (yeast form) culture media & temperature
BHI agar-blood, 37
90
***Most virulent*** of all human mycotic agents
Coccidioides spp.
90
**Inhalation** of only a few arthroconidia produces
_______________ (pulmonary disease)
primary coccidioidomycosis
91
Symptom may present as **allergic manifestations** such as:
- Toxic erythema
- Erythema nodosum
(desert bumps)
- Erythema multiforme (valley fever)
- Arthritis (desert rheumatism).
Coccidioides spp.
92
**Filipinos** and **blacks** run the highest risk of
dissemination
Coccidioides spp.
92
Fever, respiratory distress, cough, anorexia, headache, malaise, and myalgia. ***can be present for 6 weeks or longer***
Respiratory symptoms of Coccidioides spp.
93
Include **nodules**, **cavitary lung disease**, and/or **progressive pulmonary disease**
Secondary coccidioidomycosis
94
Macroscopically, it is characterized by **rapid** growth, ***white to tan to dark gray***
C. immitis and C. posadasii at 22C
95
Macroscopically, its ***young colonies***
are **tenacious**, ***older colonies*** are **cottony**, and tend to grow in *concentric rings*
C. immitis and C. posadasii at 22C
96
Microscopically, ***C. immitis and C. posadasii*** have alternating one- celled ________ arthroconidia with **disjunction cell**
“barrel- shaped”
96
_________ can be converted to the _________ in ***modified converse medium*** at 40C in **5% to 10% carbon dioxide**
Coccidioides immitis; spherule phase
96
IDENTIFY:
- Usually seen in **endemic region** of *Southeast Asia*
- Infections are usually **disseminated**, with ***multiple*** organ involvement
- Appears as ***cutaneous*** lesions
- Can be **typically fatal**
Talaromyces marneffei
97
**Only true pathogen** of Talaromyces spp.
Talaromyces marneffei
98
This organism is seen in **Wright stained smears**
Talaromyces marneffei yeast form
98
Specimen used for Talaromyces marneffei
1. Skin lesions
2. Biopsy specimens
99
When cultured, it appears **sparse green arial hyphae, reddish-brown vegetative** hyphae, and produces **red diffusible pigment**
T. marneffei mold form
99
May **resemble H. capsulatum**. **Oval** to **cylindric** measuring 3-6 um long
Biopsy specimen of T. marneffei
100
Also known as **desert bumps**
Erythema nodosum
101
Erythema multiforme is also called
Valley fever
101
Also known as **desert rheumatism**
Arthritis
