MLS 314 (MYCOLOGY AND VIROLOGY) – WEEK 3 & WEEK 4 Flashcards
1
Q
Obsoleted names of Horteae werneckii
A
Phaeoannellomyces werneckii, Exophiala werneckii, Cladosporium wernecki
2
Q
Member of the black yeasts-like species containing a wide hyphae that become profusely septate during growth of the fungus, and they have annellidic conidiogenesis from broad scars.
A
Horteae werneckii
3
Q
Halophilic species lives in seawater, mollusks, and other saline habitats
A
Horteae werneckii
4
Q
a superficial, asymptomatic fungal infection of the skin, usu. on the palms of the hands and occ. on other parts of the body
A
tinea nigra palmaris, keratomycosis nigricans
5
Q
Lesions are flat, smooth, not scaly, and appear as irregularly shaped brown to black spots resembling Ag(NO3)2 stains
A
Horteae werneckii
6
Q
The palmar and plantar lesions (stratum corneum) may also resemble melanoma.
A
Horteae werneckii
7
Q
reveals multiple brownish to black hyperpigmented maculae from a bilateral tinea nigra of palm
A
Horteae werneckii
8
Q
Malassezia furfur syn.
A
Pityrosporum furfur
Pityrosporum ovale pro parte
9
Q
contains 15 lipid-dependent species that are widely distributed in humans and other animals (eg., canine).
A
Malassezia
10
Q
Differentiation requires molecular sequencing
most clinical laboratories prefer to report results as
A
Malassezia
“Malassezia furfur species complex”
“Malassezia species”.
11
Q
Malassezia furfur
The most common species include:
A
- M. furfur
- M. pachydermatis
- M. sympodialis
- M. globosa
- M. obtusa
- M. sloofiae
12
Q
- non-lipid dependent
-Frequent colonizer of canine auditory canals
- linked to systemic infections in neonates
A
M. pachydermatis
13
Q
are the main causative agents of the skin infection pityriasis versicolor. 1 (syn. tinea versicolor)
A
M. furfur
M. sympodialis
M. globosa
M. slooffiae
14
Q
Tissue reaction reveals lesion that appear as scaly, discrete, or concrescent, hypopigmented ,and(or) mild to moderate hyperkeratosis and acanthosis on the stratum corneum chiefly on the neck, torso, and limbs.
A
Malassezia furfur
Scaly - (furfuraceous)
15
Q
Infection is largely cosmetic.
A
Malassezia furfur
16
Q
There may be a minimal mononuclear response in the dermis
A
Malassezia furfur
17
Q
Other dermatological diseases include seborrheic dermatitis (esp. in patients with AIDS), atopic eczema, psoriasis, and folliculitis.
A
Malassezia furfur
18
Q
May also cause fungemia and occ. systemic infection (most frequently involving the lung) in patients receiving prolonged infusion of lipid formulation through contaminated central venous catheters.
A
Malassezia furfur
19
Q
Predisposing factors include poor nutrition, excessive sweating, pregnancy.
A
Malassezia furfur
20
Q
Etiologic agent of the fungal infection called black piedra
A
Piedraia horteae
21
Q
The site of infection include the scalp hair, less commonly of the beard or moustache, and rarely of axillary or pubic hairs.
A
Piedraia hortae
22
Q
The disease is characterized by the presence of discrete, hard, gritty, dark brown to black nodules adhering firmly to the hair shaft.
A
Piedraia hortae
23
Q
Found mostly in tropical regions in Africa, Asia, and Central and South America.
A
Piedraia hortae
24
Q
Humans as well as other primates are infected.
A
Piedraia hortae
25
Note the the oval to elongate-shaped brown nodules affecting the hair shaft. These nodules are gritty on palpation.
Piedraia hortae
26
The nodules are usually multiple and vary in size from microscopic to 1 mm or more in diameter.
Piedraia hortae
27
They are oval or elongated in shape with their thickness tapering from one end to the other or from the middle to the edge.
Piedraia hortae
28
They are composed of a compact cellular substance that surrounds the hair shaft.
Piedraia hortae
29
Hair shafts affected by these nodules become weak and often break at the point of infection.
Piedraia horteae
30
The disease is chronic and can last for months or even years
Piedraia hortae
31
Trichosporon ovoides
Corrected name from formerly described and obsoleted
Trichosporon beigelii or Trichosporon curateum (now Cutaneotrichosporon cutaneum)
32
Causes scalp hair white piedra that infects hair shaft characterized by the presence of soft white, yellowish, beige, or greenish nodules found chiefly on facial, axillary, or genital hairs and less commonly on the scalp, eyebrows, and eyelashes.
Trichosporon ovoides
33
CCauses scalp hair white piedra that infects hair shaft characterized by the presence of soft white, yellowish, beige, or greenish nodules found chiefly on facial, axillary, or genital hairs and less commonly on the scalp, eyebrows, and eyelashes.
Trichosporon ovoides
34
Nodules may be discrete or more often coalescent, forming an irregular transparent sheath
Trichosporon ovoides
35
is the cause of summer-type hypersensitivity in Japan
shares antigenicity with the capsular polysaccharide of C. neoformans
T. asahii
36
this may yield a positive CALAS assay on serum of some patients with disseminated Trichosporon disease
C. neoformans
37
Skin scrapings from dark pigmented lesions.
Horteae werneckii)
38
Slow grower and typically matures within 21 days.
Horteae werneckii
Piedraia hortae
39
Horteae werneckii: Colony morphology
(SDA)
40
Obverse: at first light colored, moist to mucoid, shiny, and yeast-like Fig. A but soon becomes olive-black. Later, grayish green hyphae may form from at the periphery, and the center may lose its shine and become olive colored due to thin layer of mycelium usu. during 2nd to 3rd week.
Horteae werneckii)
41
Reverse is black
Horteae werneckii
Piedraia hortae
42
Wood’s lamp: No fluorescence
Horteae werneckii
43
Skin scrapings from discolored area, blood, or tissue
Malassezia furfur
44
Rapid; mature in 5 days at 30-35oC. Grow poorly at 25oC
Malassezia furfur
45
Colony morphology (SDA + cycloheximide + olive or vegetable oil)
Malassezia furfur
46
Malassezia furfur
Scrapings may also be inoculated on (?)
Leeming, or Notman medium
47
Obverse: Smooth, cream to yellowish brown, often becomes dry, dull, brittle, and wrinkled with age.
Malassezia furfur
48
Reverse is not applicable
Malassezia furfur
Trichosporon ovoides
49
Malassezia furfur
Wood’s lamp: Fluoresces yellow-green with black due to Malassezia’s production of (?), a tryptophan derivative
pityrialactone
50
Hair fragments containing one or more black nodules, collected by clipping or by plucking
Piedraia hortae
51
Slow growth; mature in 21 days
Piedraia hortae
Horteae werneckii
52
Colony morphology
[SDA + chloramphenicol or cycloheximide]
addition of (?) increase the mycelial production.
Piedraia hortae
thiamine
53
Obverse: Colonies are small, adherent, compact, somewhat raised, and dark greenish brown to black and may be glabrous or covered with very short aerial hyphae. (Fig. A) Reddish brown, diffusible pigment may form. (Fig. B)
Piedraia hortae
54
Reverse is black
Piedraia hortae
Horteae werneckii
55
Hair fragments containing the adherent nodules
Trichosporon ovoides
56
Moderately rapid; mature in 5-7 days
Trichosporon ovoides
57
Colony morphology [SDA + chloramphenicol)
Trichosporon ovoides
58
Cycloheximide is inhibitory to some species.
Trichosporon ovoides
59
Obverse: Yeastlike; at first cream colored, moist, and soft. The surface may become irregularly wrinkled, rather powdery or crumblike; the center may become heaped, and the colony may adhere to, and crack, the agar. The color often darkens to yellowish gray. Fig. A
Trichosporon ovoides
60
Reverse is not applicable
Malassezia furfur
Trichosporon ovoides
61
The early phase consists mainly of pale or dark brown, yeast like cells. Mature forms are one or two celled (3-5 x 7-10 µm)—annellides (round at one end while tapered and elongated with striations at the end where conidia are formed.
Horteae werneckii)
62
With age, dark, closely septated, thick-walled hyphae develop.
Horteae werneckii
Piedraia hortae
63
Annelloconidia may form and accumulate at annellidic points
along the hyphae. Each conidium can function as an annellide
and produce new conidia.
Horteae werneckii)
64
Chlamydoconidia may develop with age.
Horteae werneckii)
65
Using 10% KOH, an observable branching filaments & of variable lengths intermingled with clusters of small, unicellular, oval & round,
budding yeast cells that resembles “spaghetti & meatball” appearance.
Malassezia furfur
66
The yeasts show the presence of collarette between mother & daughter cells (budding is phialidic & unipolar) and average of 4µm (up to 8µm) in size.
Malassezia furfur
67
Hyphae are closely septate, dark, and thick walled and vary in diameter; with many intercalary chlamydoconidialike cells. Asci may be produced in culture.
Piedraia hortae
68
The walls of the asci readily dissolve,
releasing singlecelled, curved ascospores (5-10 x 30-35µm) that taper at the ends to form whip-like extensions.
Piedraia hortae
69
The ascospores are more likely to be seen on direct microscopic examination of the specimen than on culture.
Piedraia hortae
70
Hair fragments are placed in 25% KOH or NaOH with 5% glycerol, heated gently and carefully squashed.
Piedraia hortae
Trichosporon ovoides
71
The squashed nodule reveal a compact masses of dark septate hyphae and round to oval asci containing two to eight hyaline, aseptate banana-shaped (fusiform) ascospores that bear one or more
appendages. Fig. A
Piedraia hortae
72
On cornmeal-Tween 80 agar at 25oC for 72h, true hyphae and pseudohyphae with blastoconidia singly or in short chains are seen. Arthroconidia (2-4 x 3-9 µm) form on older cultures. The presence of pseudohyphae and blastoconidia differentiates Trichosporon from Geotrichum
spp
Trichosporon ovoides
73
Hair fragments are placed in 10% KOH or 25% NaOH-5% glycerol.
Trichosporon ovoides
74
The squashed nodule reveals an
intertwined hyaline septate hyphae, hyphae breaking up into oval or rectangular arthroconidia of 2-4µm [$]. Fig. A, occasional blastoconidia, and bacteria that may surround the nodule as a zooglea (jelly-like mass).
Trichosporon ovoides
75
Note the two-celled yeast like cells
(annellides) that is round at one end and tapered and elongated with striations at the other end where conidia are formed.
Horteae werneckii
76
Brown filaments in
NaOH mount of scraping from tinea
nigra.
Horteae werneckii
77
Note the septate hyphal elements and two-celled,
pale brown, cylindrical to spindle-shaped yeast-like
cells that taper towards the ends to form an annellide. Septa is darkly pigmented.
Horteae werneckii
78
Note the concentric hypopigmentation of the outer layer of the skin.
Malassezia furfur
79
Acanthosis like chromic pityriasis versicolor.
Malassezia furfur
80
Abundant growth of is evident
on a plate that was overlaid
with oil before the inoculum
was applied. No growth is
seen on a companion plate
without oil. (dextrose agar.)
Malassezia furfur
81
M. furfur in skin scrapings from a lesion of tinea versicolor (Kane’s stain). Note the “spaghetti and meatball’’ appearance. x 100.
Malassezia furfur
82
Macroscopic aspect of the colony on Agar Sabouraud, showing black velvety aerial mycelia colony raised in the center and flat in the periphery.
Piedraia hortae
83
Note the dark brown-black outer
perimeter, with a white central
region. Note the characteristic
reddish agar surrounding the
colony’s perimeter caused by a
reddish pigment produced by the
colonial organisms.
Piedraia hortae
84
The squashed nodule reveal a compact masses of dark septate hyphae and round to oval asci containing two to eight hyaline, aseptate bananashaped (fusiform)
ascospores that bear one or
more appendages
Piedraia hortae
85
Colonies are cream to yellow, smooth or lightly wrinkled, glistening or dull, and with the margin being either entire or lobate
M. fufur on Modified Dixon’s agar
86
Yeastlike cells (1.5 x 4.5 x
3-7 µm) are actually
phialides with small
collarettes. Cells are round
at one end and bluntly cut
off at the other, where wide
budlike structures form
singly; the buds are usually
on a broad base, but narrow
in some species
Malassezia furfur
87
Microscopic appearance
of yeast cells on
Littman oxgall overlaid with
olive oil. x 400.
M. furfur
88
Short chains, curved accompanied by clusters of oval to round, thick-walled
cells
M. furfur yeast cells on
Littman oxgall
89
Note the multiple hypopigmented bead-like nodules on the
distal hair shaft of the scalp.
Trichosporon species
90
Obverse: Yeastlike; at first cream
colored, moist, and soft. The surface
may become irregularly wrinkled,
rather powdery or crumblike; the
center may become heaped, and the
colony may adhere to, and crack, the
agar. The color often darkens to
yellowish gray.
Trichosporon species
91
Colonies are
white to cream colored,
powdery, sued-like to farinose with radial furrows and irregular folds.
T. asahii
92
T. inkin. Colonies are
restricted, white, finely
cerebriform with a granular
covering, without marginal
zone, often cracking the
media
Trichosporon species
93
Occasional blastoconidia,
and bacteria that may
surround the nodule as a
zooglea (jelly-like mass)
Trichosporon species
94
On cornmeal-Tween 80 agar
at 25oC for 72h, true hyphae
and pseudohyphae with
blastoconidia singly or in
short chains are seen.
Arthroconidia (2-4 x 3-9 µm)
form on older cultures. The
presence of pseudohyphae
and blastoconidia
differentiates Trichosporon
from Geotrichum spp.
Trichosporon species
95
Etiologic agents of dermatophytosis (“plant of the skin”) have been classified along with some nonpathogenic relatives in three anamorphic genera in the family Arthrodermataceae of the order Onygenales 2, phylum Ascomycota.
Microsporum
Trichophyton
Epidermophyton
96
Two population genetics patterns:
1. Population hosts
2. Occasional hosts
97
which is the normal epidemiologic reservoir of
the species.
Population hosts
98
species that may acquire infection but that do
not support ongoing populations.
Occasional hosts
99
(?) has mostly feline population hosts, and while humans are frequently infected by feline carriers, the species is seldom directly transmitted from human to human, making the
human species only an “occasional host”.
100
(?) are keratinophilic (keratin as the nitrogen
source) and group into three categories based on host preference
and natural habitat
Dermatophytes
101
(?) species almost exclusively infect humans; animals are rarely infected and transmitted via direct or indirect
contact.
Anthropophilic
102
(?) species are soil-associated organisms, and soil per se
or soilborne keratinous debris (eg., shed hairs, molted feathers) is
a source of infection for humans as well as for other animals.
Geophilic
103
(?) species are essentially pathogens of non-human
mammals or, rarely birds; however animal-to-animal transmission is not common.
Zoophilic
104
Some dermatophytes eg., T. rubrum are cosmopolitan, whereas others eg., (?), are geographically limited (found only in the Pacific Islands and regions in Southeast Asia and Central and South America)
T. concentricum
105
-generally manifests as infections of
the keratinized tissues (hair, skin, nails, etc.) of
humans, other mammals, and birds.
Primary
dermatophytoses
106
- described as cutaneous infections
resembling dermatophytoses that may occasionally be caused by yeasts
or by unrelated filamentous fungi that are normally saprobes or plant
pathogens
Opportunistic dermatomycoses
107
Tissue invasion is normally cutaneous, and unable to penetrate deeper tissues due to:
1. Nonspecific inhibitory factors in
serum
2. Inhibition of fungal keratinases
3. Barrier formed of epidermal
keratinocytes
4. Other immunological
barriers
108
Anthropophilic species
Epidermophyton floccosum
Microsporum audouinii
Trichophyton concentricum
T. mentagrophytes complex (velvety and
cottony isolates)
Trichophyton rubrum
Trichophyton schoenleinii
Trichophyton tonsurans
Trichophyton violaceum
109
Zoophilic species
Microsporum canis
T. mentagrophytes complex (granular isolates)
Trichophyton verrucosum
110
Geophilic species
Microsporum gypseum (Nannizzia
gypsea) complex
Trichophyton vanbreuseghenii
111
(?) is highly contagious
and may spread rapidly within a
family, institution, or school.
Tinea capitis
112
(?) is associated with shared clothing, towels, and sanitary
facilities.
Tinea cruris
113
(?) often involves communal showers,
baths, or other aquatic facilities but
may depend on environmental and
host factors.
Tinea pedis and Tinea unguium
114
Acquisition of (?) has been suggested to require a dominant autosomal susceptibility gene
T. rubrum tinea
pedis
115
(?) result from animal-tohuman contact or from indirect transmission involving fomites.
Zoophilic
116
(?) involves transmission of
soilborne inoculum to humans or
other mammals.
Geophilic
117
Usually carried out by
arthroconidia that have been
formed in or on infected host tissue
Transmission of CUTANEOUS FUNGI
118
Infections caused by (?) are named according to the anatomic location involved by their Latin names
dermatophytes
119
(?) infection of the bearded areas of the face and neck, moustache
Tinea barbae
120
(?) infection of the scalp and hair shaft, eyebrows and eyelashes
Tinea capitis
121
(?) infection of the glabrous skin on body parts not otherwise specified (usu. the trunk of the body, face, and major limbs)
Tinea corporis
122
(?) infection of the groin, perineum, and perianal region
Tinea cruris
123
(?) infection of the hand (palms)
Tinea manuum
124
(?) infection of the feet (soles and toe
webs)
Tinea pedis
125
(?) infection of the nails (onychomycosis is infection of the nail caused by any fungus, not necessarily caused by a dermatophyte)
Tinea unguium
126
Dermatophytes grow in an annular fashion on
most affected regions, producing a “(?)” infection form with a more or less raised and erythematous active area at the periphery and relatively scaly inactive zone at the center of established lesions.
ringworm
127
(?) patients may developed subcutaneous infections eg., Majocchi’s granuloma (aka. granuloma trichophyticum), kerion, mycetoma-like processes.
Immunocompromised
128
Principal current risk factors for common forms of dermatophytosis:
1. Age (youth for tinea capitis, advanced age for onychomycosis)
2. Family history of chronic dermatophytosis
3. Participation in athletics featuring extensive body contact (eg., wrestling, judo)
4. Foot maceration (eg., marathon running); Barefoot use of communal aquatic facilities
(showers, swimming areas)
5. Exchange of headgear, footwear, or inadequately cleaned bedding.
6. Contact with feral domestic animals (esp. street kittens)
129
Most common for Tinea favosa
T. schoenleinii
130
Less frequent
T. violaceum
131
(?), chronic lesions on the trunk and extremities particularly the Afro-Asiatic forms.
Tinea corporis
132
(“jock itch”)
Tinea cruris
133
(?), distalsubungual onychomycosis
Tinea unguium
134
Clinical features of Anthropophilic
T. schoenleinii
T. violaceum
Tinea corporis
Tinea cruris
Tinea manuum
Tinea pedis
Tinea unguium
Tinea pedis
E. floccosum
T. tonsurans
135
(?), lesions vary from highly erythematous, patchy, scaly areas with dull gray hair stumps to highly
inflamed lesions with folliculitis, kerion, alopecia, and scarring.
Tinea capitis
136
complex, granular
T. mentagrophytes
137
Less frequent
T. verrucosum
138
(?), highly inflamed and may present as acute pustular folliculitis that can progress to suppurative boggy lesions (kerion). Less severe lesions appear as dry, erythematous and scaly.
Tinea barbae
139
Clinical features
of Zoophilic
Tinea capitis
T. mentagrophytes
T. verrucosum
Tinea barbae
140
Geophilic
Less frequent
M. gypseum complex
141
(?), very rare chronic infection of
the scalp and glabrous skin characterized by the formation of cupshaped crusts (scutula) resembling honeycombs
Tinea favosa (favus),
142
M. gypseum complex
includes:
1. Arthroderma gypseum
2. A. incurvatum
3. A. fulvum
4. Microsporum duboisii
143
Dermatophytosis of the body or trunk plus neck and shoulder.
Tinea corporis
144
Erythematous circular lesions, scaly patch with
sharply demarcated margins resulting in abnormallooking patch of the skin at the hub of the week or ring
Tinea corporis
145
Can be transmitted via direct contact with an
infected person, by fomites, or by autoinoculation.
Tinea corporis
146
• Diagnose by examination of a direct preparation
of the skin scales.
Tinea corporis
147
• Agents: [rank according to frequency]
1. T. rubrum
2. Zoophilic dermatophytes
3. Any of the dermatophytes
Tinea corporis
148
Tinea cruris (“jock itch”)
149
Dermatophytosis of the proximal medial thighs,
perineum, and buttocks.
Tinea cruris (“jock itch”)
150
Lesion appears scaly, erythematous to tawny
brown, bilateral and asymmetric lesions extending
down to the inner thigh and exhibiting a sharply
marginated border frequently studded with small
vesicles.
Tinea cruris (“jock itch”)
151
• Agents: [rank according to frequency]
1. T. rubrum
2. E. floccosum
Tinea cruris (“jock itch”)
152
Dermatophytosis of the feet (“athlete’s foot”)
Tinea pedis
153
Lesion varies in appearance: the most common
manifestation is maceration, peeling, pruritic, and
painful fissuring between the fourth and fifth toes,
but an acute inflammatory condition with vesicles
and pustules can also occur, as can a
hyperkeratotic chronic infection of the sole
(“moccasin foot”)
Tinea pedis
154
• Agents: [rank according to frequency]
1. T. rubrum causes chronic infection
2. E. floccosum causes acute infection that
spontaneously resolve
Tinea pedis
155
• Agents: [rank according to frequency]
1. T. mentagrophytes
2. T. rubrum
3. E. floccosum
Tinea manuum
156
Dermatophyte infections on the palms and
between fingers.
Tinea manuum
157
Most cases occur in patients who also have tinea
pedis, and the infections caused by the same
causative dermatophyte.
Tinea manuum
158
Occurs only on the bearded areas of the face and
neck.
Tinea barbae
159
Superficial form: resemble tinea corporis
Tinea barbae
160
Pustular form: associated with zoophilic
dermatophytes (folliculitis is the inflammation of
hair follicles)
Tinea barbae
161
Boggy tumefactions, a kerion appears as an
inflamed, thickened, pus-filled area, and it
sometimes accompanied by a fever.
Tinea barbae
162
• May develop to alopecia and permanent scarring
Tinea barbae
162
• Agents: [rank according to frequency]
1. T. verrucosum
2. T. mentagrophytes
Tinea barbae
163
Dermatophytosis of the nails. Subcategory of the
more general phenomenon of onychomycosis.
Tinea unguium
164
• Superficial form: whitish patches on the surface
of the nail contain fungus without nail distortion,
usu. caused by T. interdigitale
Tinea unguium
165
Subungual form: deep layers of the skin is
invaded. The nail becomes brittle and thickened
and is frequently discolored. Debris from the
fungus & from tissue destruction accumulate in the
nail, causing distortion and cracking
Tinea unguium
166
• Agents: [rank according to frequency]
1. T. rubrum may cause “proximal-subungual tinea
unguium”1
2. T. interdigitale (“nodular” variant of T.
mentagrophytes)
Tinea unguium
167
Dermatophytosis of the hair of the scalp,
eyebrows, and eyelashes.
Tinea capitis
168
May vary from highly erythematous, patchy,
scaly areas with dull gray hair stumps or highly
inflamed lesions with folliculitis, kerion formation,
alopecia, and scarring
Tinea capitis
169
• Agents: [rank according to frequency]
1. T. tonsurans
2. M. canis
Tinea capitis
170
Specialized form of tinea corporis.
Tinea imbricata
171
Lesion are ringlike growth in overlapping circles.
Tinea imbricata
172
• Agents: [rank according to frequency]
1. T. concentricum
Tinea imbricata
173
Direct microscopy of infected dermatological
specimens (ie., skin, nails) may reveal one or more
of the following indicators:
1. Hyaline hyphal fragments
2. Septate, often branching hyphae
3. Chains of arthroconidia
174
• The appearance of of infected hairs depends on the invading (?) species.
dermatophyte
175
Hyphae invade the hairs, and arthroconidia are formed by fragmentation of the (?).
hyphae
176
The appearance and location of (?) may suggest the infecting genera or species.
arthroconidia
177
Distinguishes between atypical isolates of the T. mentagrophytes complex and T. rubrum.
178
• Distinguishes between atypical isolates of the
T. mentagrophytes complex and T. rubrum
179
• It may also be used for [?] that show wedgeshaped perforations perpendicular to
the hair shaft (a positive test result).
M. canis and M. gypseum
180
• Sterile [?] of healthy human hair fragment. Place 8-10 hair fragments into a 50 mL screw-cap tube and add [?] of sterile distilled water and [?] filter-sterilized yeast extract.
1 cm
20-25 mL
0.1 mL of 10%
181
• Place several fragments of the [?] in the tube.
fungal culture
182
• Incubate at [?] or until a positive reaction is seen (~8-10 days)
RT for 21 days
183
• Look for [?] caused by hyphae that penetrate the hairs perpendicularly.
wedge-shaped perforations
184
Three types of hair colonization
1. Ectothrix
2. Endothrix
3. Favic
185
M. audouinii
M. canis
M. ferrugineum
M. gypseum (Nannizzia
gypsea) complex
M. (Nannizzia) praecox
T. megninii
T. mentagrophytes complex
T. verrucosum
Ectothrix
186
T. soudanense
T. tonsurans
T. violaceum
Endothrix
187
T. schoënleinii
Favic
188
• Arthroconidia appear as a “tile mosaic sheath” around the hair or as
chains on the surface of the hair shaft
Ectothrix
189
Hair becomes grayish, dull and discolored; eventually the hair
becomes brittle and breaks off.
Ectothrix
190
M. canis, M. audouinii, and M. ferrugineum infections, colonized
hairs fluoresce green ender the Wood’s lamp
Ectothrix
191
Observed as chains of arthroconidia filling the insides of shortened
hair stubs
. Endothrix
192
The presence of conidia weakens the hair so that it loses is luster,
becomes brittle, and breaks off above the surface of the scalp.
. Endothrix
193
As it continues to grow, the conidia in the shafts of the hair stubs
appear black dots leaving a grayish patch “Gray patch”
. Endothrix
194
• Hairs are Wood’s lamp negative
. Endothrix
195
Creates parallel lesions with the hair shaft
Favic
196
Hair shaft is filled with long filamentous arthroconidia; empty
airfilled areas are left in the hair when they hyphae degenerate into
fat droplets. Lesions have a “mousy” odor.
Favic
197
Clinical entity characterized by the occurrence of dense masses of
mycelium & epithelial debris which forms yellowish, cup-shaped
crusts called scutula.
Favic
198
Dull green under the Woods’s lamp.
Favic
199
moderate to rapid grower
Microsporum audouinii
Microsporum gypseum complex
200
rapid grower
Microsporum canis var. canis
Trichophyton mentagrophytes
201
moderate to rapid grower
Microsporum gypseum complex
202
moderate to slow grower
Trichophyton rubrum
203
slow grower
Trichophyton schoenleinii
204
• Flat to velvety, thin, pale
salmon to pale brownish
reverse.
Microsporum audouinii
205
• Rare deformed
macroconidia, often with
break, constricted mid
region & at least trace
granulation
Microsporum audouinii
206
• Drop shaped
microconidia and aerial
arthroconidia may be
present. pectinate
branching
Microsporum audouinii
207
• Apiculate terminal
chlamydospores often
seen
Microsporum audouinii
207
• Flat to velvety, thin, pale
to yellow, with yellow
(rarely pale) reverse
Microsporum canis var. canis
208
• Macroconidia thickwalled, roughened and
beaked.
Microsporum canis var. canis
209
• Microconidia dropshaped.
Microsporum canis var. canis
210
• Granular, sandy in color,
or occasionally light
cinnamon or rosy buff.
Microsporum gypseum complex
211
• Reverse usually pale to
brownish
Microsporum gypseum complex
212
• Macroconidia abundant,
thin walled, fusoid
(tapered at both ends)
roughened with up to six
septa.
Microsporum gypseum complex
213
• Microconidia drop
shaped mostly formed
along sparsely branched
hyphae.
Microsporum gypseum complex
214
• Granular to powdery,
yellow-cream to buff
surface.
Trichophyton mentagrophytes
215
• Macroconidia
uncommon, club shaped,
smooth.
Trichophyton mentagrophytes
216
• Pale to red brown
reverse.
Trichophyton mentagrophytes
216
• Microconidia nearly
spherical, abundant,
mostly produced in dense
tufts; spiral appendages
present.
Trichophyton mentagrophytes
217
• Microconidia drop
shaped, abundant scanty
or not formed; lateral
hyphal projections often
present
Trichophyton rubrum
218
• Macroconidia abundant,
club-shaped, sometime
with rat-tail extension.
Trichophyton rubrum
219
• Typically wine red
reverse but yellow variants
occasional; red color
poorly formed in presence
of common bacterial
contamination
Trichophyton rubrum
220
• Powdery to low velvety,
cream to deep red
Trichophyton rubrum
221
• Convoluted with
glabrous texture, heaped
or folded topography.
Slightly velvety whitish
colony
Trichophyton schoenleinii
222
• No conidia seen.
Trichophyton schoenleinii
223
• Favic chandeliers or
nailhead hyphae are
present
Trichophyton schoenleinii
224
• Surface is brownish
yellow to olive gray or
khaki with a suede like
surface, raised and folded
in the center, with a flat
periphery and submerged
fringe of growth
Epidermophyton floccosum
225
• Macroconidia is
abundant, smooth thinwalled which are often
produced in clusters
growing directly from
hyphae. Usually,
macroconidia contains 6
cells.
Epidermophyton floccosum
226
• Numerous
chlamydospores may be
formed in primary
isolates1. Microconidia is
not formed.
Epidermophyton floccosum
