dermatophytes

Question 1

the cause of tinea or ringworm infections

Answer 1

dermatophytes

Question 2

common characteristics of dermatophytes

Answer 2

all have septate hyphae- slow growers
often seen in KOH prep
ID by type of conidia they have
found on supporting structures known as conidiophores

Question 3

microsporum

Answer 3

infect hair and skin
IF macroconidia- thick walled

macro and micro

Question 4

trichophyton

Answer 4

infect hair, skin, and nails
if there are macro conidia they are thin walled

Question 5

epidermopyton

Answer 5

infect skin and nails
macroconidia- club shaped; rare

Question 6

dermatophytes can cause the hair to have

Answer 6

endothrix or ecothrix

Question 7

ecothrix

Answer 7

usually doesn’t invade into the hair shaft

Question 8

endothrix

Answer 8

means that is normally will invade into the hair shaft itself

Question 9

what are dermatophytes best plated on

Answer 9

cornmeal or potato dextrose

Question 10

gold standard for viewing conidial structure

Answer 10

slide cultures

Question 11

microsporum audouinii

Answer 11

more common in kids
infect scalp, sometimes skin
microscop- juse see sterile hyphae (no spores); a few chlamydospores

comb like pectinate hyphae

wood lamps+

Question 12

microsporum audouinii color

Answer 12

greyish white in color

Question 13

Microsporum canis

Answer 13

transmitted puppies or kittens

scalp or skin infections

fluffy, yellow pigmented
reverse yellow

Question 14

Microsporum canis ID

Answer 14

by macroconidia- have 6 septations and pointed ends

remember all dermatophytes have septate hyphae

Question 15

microsporum gypseum

Answer 15

adults
geophilic organism and transmitted by infected dirt

skin infections

Question 16

how is gypsum differentiated from canis

Answer 16

gypseum is more rounded at the end
-6 or less septations and described as cigar shaped

Question 17

Trichophyton mentagrophytes

Answer 17

very common in lab
transmitted: animals, dirt of humans

common cause of athletes foot and infection of nails

Question 18

Trichophyton mentagrophytes
hair infection type

Answer 18

endothrix- infect shaft

can see in hair penetration test

urea + in 4 days

Question 19

characteristics of Trichophyton mentagrophytes

Answer 19

microconidia looks like cross
characteristics coiling!!

Question 20

how is Trichophyton mentagrophytes
different from canis

Answer 20

mentagrophytes
-top is tan or buff colored and reverse is salmon

Question 21

most common infecting human

Answer 21

T.Rubrum

-mainly affecting skin and nails

Question 22

T.Rubrum

Answer 22

another common cause of athletes foot

elliptical or tear drop shape
micro- resemble “birds on a wire”

Question 23

T.Rubrum color

Answer 23

whitish and reverse is red
-enhance on corn meal

Question 24

major cause of tinea capitis

Answer 24

T.tonsurans

Question 25

disease that T.tonsurans causes

Answer 25

black dot ringworm -hair will break off at shaft of scalp leaving black dot

Question 26

T.tonsurans microscopically

Answer 26

bizarre shaped microcon may see club shaped or balloon may see chlamydospores

Question 27

most severe form of tinea capitis

Answer 27

T.schoenleneii

Question 28

T.schoenleneii infection

Answer 28

may result in permanent hair loss and scarring of scalp called favus

Question 29

T.schoenleneii microscopically

Answer 29

produce irregular hyphae said to look like favic chandeliars -moose antlers no macro or micro conidia

Question 30

common cause of jock itch

Answer 30

Epidermophyton floccosum

Question 31

Epidermophyton floccosum ID

Answer 31

club shaped macro conidia in clusters of 2 or 3 at the end of hypael element looks different for each cultures