Cutaneous and Subcutaneous Mycoses PART2

Question 1

are immediately recognized by the
presence of large (8 to 15 μm × 35 to
150 μm) spindle-shaped, echinulate
(covered with small spines), rough-walled macroconidia with thick walls (up to 4 μm) containing four or more septa

Answer 1

Microsporum spp.

Question 2

The exception Microsporum
which characteristically produces
macroconidia with two cells instead of 4 or more cells

Answer 2

Microsporum nanum,

Question 3

Microconidia, when present, are
small (3 to 7 μm) and club-shaped
and are borne on the hyphae, either
laterally or on short conidiophores.

Answer 3

Microsporum spp.

Question 4

develop either rapidly or slowly (5 to 14 days) and produce aerial hyphae that may be velvety, powdery, glabrous, or cottony, varying in color from whitish, to buff, to a
CINNAMON BROWN with varying shades
on the reverse side of the colony.

Answer 4

Microsporum spp.

Question 5

is anthropophilic and is spread directly by
means of infected hairs on hats, caps, upholstery, combs, or barber clippers
.Most infections are chronic; some heal spontaneously, whereas others may persist for several years

Answer 5

M. audouinii

Question 6

Infected hair shafts fluoresce yellow-green under a Woods lamp. Grow more slowly than other members of the genus Microsporum (10 to 21 days)

Answer 6

M. audouinii

Question 7

• produce a velvety aerial mycelium that is colorless to light gray to tan
• reverse side often appears salmon-pink to
  reddish-brown

Answer 7

M. audouinii

Question 8

Most commonly, atypical vegetative forms, such as terminal chlamydoconidia and antler and racquet hyphae, are the only clues to the identification of this organism

Answer 8

M. audouinii

Question 9

often is identified as a cause of infection by
exclusion of all the other dermatophytes.

Answer 9

M. audouinii

Question 10

primarily a pathogen of animals (zoophilic) .Hairs infected with ___fluoresce a bright
yellow-green under a Woods lamp

Answer 10

M. canis

Question 11

Direct examination of a calcofluor white or potassium hydroxide preparation of infected hairs reveals small spores (2 to 3 μm) outside the hair

Answer 11

M. canis

Question 12

grow rapidly, are granular or fluffy with a feathery border, white to buff, and characteristically have a lemon-yellow or yellow-orange fringe at the periphery

Answer 12

M. canis

Question 13

On aging, the colony becomes dense and cottony and a deeper brownish-yellow or -orange and frequently shows an area of heavy growth in the center

Answer 13

M. canis

Question 14

reverse side of the colony is bright yellow, becoming orange- or reddish-brown with age

Answer 14

M. canis

Question 15

shows an abundance of large
(15 to 20 μm × 60 to 125 μm), spindle shaped,
multisegmented (four to eight) macroconidia with curved ends; thick-walled with spiny (echinulate) projections on their surfaces

Answer 15

M. canis

Question 16

free-living fungi of the soil (geophilic) that
only rarely causes human or animal infection and occasionally m .Infected hairs generally do not fluoresce under a Woods lamp

Answer 16

M. gypseum

Question 17

microscopic examination of the infected hairs shows them to be irregularly covered with clusters of spores (5 to 8 μm), some in chains

Answer 17

M. gypseum

Question 18

grow rapidly as flat, irregularly fringed colonies with a coarse, powdery surface that appear to be buff or cinnamon colored

Answer 18

M. gypseum

Question 19

underside of the colony is orange to brownish

Answer 19

M. gypseum

Question 20

macroconidia are seen in large numbers and are characteristically large, are ellipsoidal, have rounded ends, and are multisegmented (three to nine) with echinulated surfaces

Answer 20

M. gypseum

Question 21

the only member of the genus Epidermophyton, is a common
cause of tinea cruris and tinea pedis

Answer 21

E. floccosum

Question 22

susceptible to cold, specimens
submitted for dermatophyte culture
should not be refrigerated before
culture, and cultures should not be
stored at 4°C

Answer 22

E. floccosum

Question 23

Direct examination of skin scrapings
using the calcofluor white or potassium hydroxide preparation, the fungus is seen as fine branching hyphae

Answer 23

E. floccosum

Question 24

grows slowly; the growth appears olive-green to khaki, with the periphery surrounded by a dull orange-brown

Answer 24

E. floccosum

Question 25

After several weeks, colonies develop
a cottony white aerial mycelium
that completely overgrows the colony the mycelium is sterile and remains so
even after subculture

Answer 25

E. floccosum

Question 26

Microscopically, numerous smooth, thin-walled, club-shaped, multiseptate (2 to 4 μm)
macroconidia are seen

Answer 26

Epidermophyton sp

Question 27

They are rounded at the tip and are
borne singly on a conidiophore or in
groups of two or three

Answer 27

Epidermophyton sp.

Question 28

Microconidia are absent, spiral
hyphae are rare, and chlamydoconidia
are usually numerous

Answer 28

Epidermophyton sp.