Basic concepts of mycology Flashcards
(121 cards)
1
Q
fungi are eukaryotic because?
A
they possess true nucleus, nuclear membrane, and mitochondria
2
Q
characteristics of yeasts
A
- single, vegetative cells (unicellular)
- moist, creamy, opaque or pasty colonies on media
3
Q
yeasts reproduce through ___ which involves maturation of the mother bud that can independent to blasticonidium
A
budding
4
Q
general considerations for the identification of molds
A
- growth rate
- colonial morphologic features
- microscopic morphologic features
5
Q
how do we differentiate fungi from other microorganisms?
A
fungi are eukaryotic while bacteria are prokaryotes
6
Q
why do fungi lack antibiotic susceptibility?
A
you cannot use antimicrobial agents, instead antifungal agents.
7
Q
fungi are ___ bcos they can acquire nutrients from their environment
A
saprophytic
8
Q
environmental requirement of fungi
A
OBLIGATE AEROBES
- they grow best at neutral pH and moisture is necessary for their growth.
9
Q
t or f: most fungi survive in dry conditions
A
true
10
Q
yeast usually appear?
A
tan to yellowish
11
Q
term refers to the daughter cells of yeast
A
blastoconidium
12
Q
in yeast, the parent cell is able to give the genetic material to the daughter cells through the process of?
A
mitosis
13
Q
molds are also known as?
A
filamentous fungi
14
Q
what makes it unique in the reproduction of molds?
A
base on their structure
15
Q
Moist, creamy, opaque or pasty colonies
A
yeast
16
Q
fluffy, cotton, wooly or powdery colonies
A
molds
17
Q
general considerations for the identification of molds
A
- growth rate
- colonial morphologic features
- fluffy, cotton, wooly or powdery colonies
- formation of mycelia
18
Q
mycelias that grow on top which tend to support the reproductive structures
A
aerial mycelia
19
Q
mycelia that grow on the bottom
A
vegetative mycelia
20
Q
mycelia that can be either aerial or vegetative
A
hyphae
21
Q
made up of many long strands of tube-like structures
A
**hyphae
22
Q
what is the best way to categorize the molds in examination of hyphae?
A
look for septate or septation
23
Q
has frequent cross walls, perpendicular to outer walls of hyphae, and looks like a separation in between
A
septate
24
Q
irregular intervals that can be found in hyphae
A
sparsely septate
25
term refers for the absence of cross walls or segments
aseptate
26
reproductive structures of molds
conidia
27
the structure that supports the conidia is ____
aerial mycelia
28
term refers to a furrowed or convoluted appearance of fungi in the media
verrucose
29
appearance of fungi in media:
slightly raised in the center
umbonate
30
what is rugose?
furrows radiate out from the center
31
slow growers fungi tend to grow?
11 - 21 days
32
intermediate growers fungi
6 - 10 days
33
growth rate for rapid growers fungi
5 days or less
34
pigmentation of fungi can either be?
hyaline of phaeoid
35
hyaline pigmentation refers to a?
nonpigmented or lightly pigmented
36
what is phaeoid?
- darkly pigmented
- melanized (dematiaceous)
37
true or false: pigmentation can only be seen with stains
false, usually seen WITHOUT stains
38
WHITEY SCALEY: hyaline or phaeoid?
phaeoid
39
how can we differentiate the type of diseases and causes of fungi?
through their pigmentation
40
stains of fungi
- Gomori methylene
- Fontana-Masson
41
black appearance which is brought by the stain?
Gomori methylene
42
using the Fontana-Masson stain, hyaline is usually seen in color?
pink to red
43
using the Fontana-Masson stain, phaeoid is usually seen in color?
brown
44
texture in loose, high aerial mycelium
cottony
45
low aerial mycelium has a ___ texture
velvety
46
texture which refers to a dense powdery resembling sugar granules
granular
47
describe the glabrous texture
smooth surface with no aerial mycelium
48
high aerial mycelium that appears slightly matted brown
wooly
49
fungi which tend to terminally change their phases
dimorphic fungi
50
mold and yeast phase
dimorphic fungi
51
temp for the dimorphic fungi mold phase
25-30C
52
temp for the yeast phase in dimorphic fungi
35-37C
53
both yeast and molds forms in the same culture
polymorphic
54
in culture, molds present as ____. they have mycelia observed
filamentous
55
fungi in the form of molds reproduce asexually or sexually?
both
56
imperfect fungi is also known as?
asexual or anamorph
57
asexual fungi are carried out by?
**Conidiogenous cells**
these cells produce the spores
58
an endogenous type of spores which has a sac-like structure and they tend to spread spores inside
sporangiospores
59
production of spores can be?
endogenous or exogenous
60
term refers to the production of spores which would spread outside
exogenous - conidiophore
61
formation of conidia is derived from?
hypha
62
- cells that contains genetic material having a fruit structure
- it holds the protein structures
conidiogenous cells
63
2 kinds of conidiogenous cells
phialides and annelides
64
phialides
base-like structure
65
the structure that holds phialides are?
conidiosphore
66
mycelia are hyphae and are the ones that support ___.
conidia
67
Without hyphae, conidiophore, and phialides, you will have ____
no conidia for reproduction
68
type of conidia having spore's formation like fragmentation
arthroconidia
69
2 types of conidium
- microconidia
- macroconidia
70
a unicellular, round, elliptical conidia
microconidia
71
a multiseptated and club or spindle shaped conidia
macroconidia
72
a saclike structure *produced at the tip* which reproduce asexually
sporangiospore
73
Asexual spores (sporangiosphore) are produced through?
sporangium
74
sexual spores are?
perfect fungi
75
fungi that reproduces sexually
teleomorph
76
asexual forms of the same fungus
synanomorphs
77
zygospores is a
sporangiospore
78
ascospores is a
conidia
79
fungi phyla
- ascomycota
- basidiomycota
- subphylum mucoromycotina
80
a group of fungi where there is no mode of reproduction or they have no means of producing sexually (imperfect fungi)
deuteromycota
81
- subphylum mucoromyctoina
- reproduce asexually
**mucorales**
(sporangiospores, sporangium, sporangiophore)
82
ascomycota (ascospores) reproduction
sexual
83
refers to the basidiospores or basidia which reproduce sexually
basidiomycota
84
50% of all named fungi belongs to this phylum
ascomycota
85
it has a distinct characteristic having a clamp connections
**BASIDIOMYCOTA**
86
biosafety cabinet for fungi
class II biosafety cabinet
87
specimen for diagnosis of fungi can be
- respiratory tract specimen (sputum, induced sputum, tracheal aspiration, bronchial washings, broncho alveolar lavage)
- CSF
- blood
- eye (corneal scrapings)
- hair
- skin
- nails
- vaginal
- urine
- tissue, bone marrow, and sterile body fluids
88
most common specimen in identifying yeast and hyphal elements
urine
89
agent used to liquefy sputum
N-acetyl-L-cysteine
90
storage req for respiratory tract specimen and the media used
room temp - processed **within 2 hrs**
refrigeration (4C) - delay
media: nonselective and media with antibacterial agents
91
storage req for CSF
should be processed immediately
- room temp or 30C
preparation: centri and filtration
92
blood cultures (automation) for blood specimen
BACTEC
ALERT
VersaTREK
93
temp req and duration for a blood sample
temp: 30C
duration: 21 days
94
a special container in which the wbc and rbc are lysed and centrifuged to get concentrates
isolator
95
storage and media used for corneal scrapings
media: non-inhibitory
storage: room temp
96
a common identifying method used for hair sample
wood lamp UV of >365 nm
97
a sample that requires aseptic technique
hair
98
incubation temp for a hair sample
22 - 30C
99
vaginal discharge should be?
- submitted w/in 24 hrs
- use of transport swab
- incubate 30C for 7 dats
- media: selective and inhibitory
100
a sample that uses a heparizined syringe and isolator tubes
bone marrow
101
used for direct microscopic examination of specimen
- KOH preparation
- KOH with calcoflour white
- India ink
- Tissue stains (periodic acid schiff and mason-fontana stain)
102
KOH preparation is used for samples like
skin, hair, nails, and tissue
103
breaks down keratin
10% - 20% potassium hydroxide solution
104
can be used with KOH, has a greater breakdown of debris, no heat required
Dimethyl sulfoxide (DMSO)
105
binds to polysaccharides in chitin walls of fungus and needs a fluorescent microscope
KOH with calcoflour white
106
+ result of KOH with calcoflour white
**fluoresce apple green or blue-white**
107
used to examine CSF
INDIA INK
- Encapsulated yeast C. neoformans
- Yeast: Clear w/ Halo (capsule
108
* a stain for detection of fungi
* hyphae of molds and yeast can be readily distinguished
Periodic Acid Schiff (PAS) Stain
109
for the examination of melanin pigment in fungal cell walls
Masson-Fontana stain
110
tease mount uses two teasing needles and the?
Lactophenol Cotton Blue (LPCB)
- Lactic acid, Phenol and dye – kills, preserves and stains
organisms
111
+ result for tease mount
blue appearance
112
The method of getting the hyphae or mycelia from the fungus
cellophane tape method
113
common or routine primary culture media for the **initial isolation** of pathogens and saprobes
**Sabouraud dextrose agar**
114
antibiotic agent that inhibit * insignificant fungal contaminants*
Cycloheximide
115
antibiotic agent that inhibit bacterial growth
Gentamicin or Chloramphenicol
116
a media that enhance the growth of dimorphic fungi
Brain-heart infusions (BHI) w/ 5% to 10% sheep blood
117
agar for the **Isolation and presumptive identification** of yeast and filamentous fungi
chromogenic agar
118
agar that allows identification of pathogenic yeast by examining the microscopic morphology of inoculum growth
Cornmeal agar
119
a test for yeast
principle: Grown with serum or plasma at __
Ability to form hyphae
germ tube
principle: Grown with serum or plasma at 35c
120
positive for germ tube
Candida albicans
121
incubation requirements for culture(temp, duration)
temp: **30C**
duration: **21 - 30 days**
cultures should be examined at least 3x weekly
