Microsporum a pathogenic fungi Which comes under dermatophytes and cause ringworm infection and fungal infection on skin. All the Introduction, morphological characteristics, pathogenesis, lab diagnosis and treatment given here. If you want better understanding go on to mine YouTube channel linked below: https://youtu.be/2wbsB8jxv6o There you can find other more interesting topics related to microbiology.

1. Pathogenic Fungi :
MICROSPORUM
Presented by:
Neha kausar Nasim
sheikh

2. CONTENT
• Introduction
• Morphological characteristics
• Pathogenesis
• Laboratory diagnosis
• Treatment

3. INTRODUCTION
• Microsporum is the genus of fungi comes under Dermatophytes
group
• Dermatophytes- it is a group of three types of fungus i.e.
Microsporum, Trichophyton and Epidermophyton that causes skin
diseases in Humans and Animals.
• Microsporum fungi infects only keratinized tissue like skin, hair
and Nails.
• They are restricted to non-viable skin because they are unable to
grow at 37 degree Celsius.
• Enzymes which helps the fungi are Proteases, Elastase,
Keratinases. These are degradative enzymes which degrade
keratinized tissue and serves as nutrients for the fungi.
• Natural habitat of some microsporum spp. Is soil(geophilic) others
primarily affect animals(zoophilic) or human(Anthropophilic).
• The infection caused by Microsporum are known as ringworm or
tinea , Though infections are not caused by worms but it appear as
snake-like on skin, hence named ringworm infection.

4. MORPHOLOGICAL CHARECTERISTICS
• Microsporum can be identified by their colonial
appearance and microscopic morphology after
growth for 2weeks at 25 degree Celsius on
Sabouraud’s dextrose agar.
• Microsporum species tend to produce distinctive
multicellular machroconidia with echinulate walls.
• Microsporum forms both Macroconidia and
Microconidia on short conidiosphores(hyphae).
MACROCONIDIA MICROCONIDIA
Large asexual
reproductive structure.
Small asexual
reproductive structure.
Hyaline, Multi sepate(2-
15)
Hyaline, single septate
Spindal shaped Club shaped
Rough and Thick walled Smooth and Thin walled
8 to 15 X 40 to 150 µ m 2 to 3 µ m

5. Microsporum canis
• Colonies :- white cottony surface and
deep yellow color on reverse, Thick
walled.
• On the rice grains, a deep yellow pigment
is produced by M.canis which helps to
differentiate it from M.audouinii
• Macroconidia are abundant. Thick walled
with many septa up to 15 . Macroconidia
are often hooked or curved at ends.
• Microconidia are small and club-shaped.
• In-vitro hair perforation test :- Positive
• M.canis causes tinea capitis and tinea
corporis. Tinea barbae, tinea mannum.

6. Microsporum audouinii
• Colonies :- dense fur like mat having radiating
edges, Grayish white to salmon pink colored
colonies.
• Pectinate hyphae and rare macroconidia and
microconidia.
• Anthropophilic.
• Hair and skin infected with M.auduinii gives
fluorescence under wood’s UV light.
• In-vitro hair perforation test :- Negative
• It causes tinea capitis and tinea corporis

7. Microsporum
gypseum
• Colonies :- forms a tan,
powdery colony, reverse colony
often appear ragged around
edges.
• Macroconidia usually have 4-6
septa.
• Microconidia are smaller than
M.canis
• Geophilic as well as Zoophilic
(fur of rodents)
• It causes Tinea capitis & Tinea
corporis

8. Microsporum ferrugineum
• Colonies:- slow growing , flat, glabrous, wrinkled, leathery
to downy.
• Pale yellow colonies on Lowenstein-Jensen medium
differentiate it from others.
• Septate hyphae usually deformed and no Macroconidia,
Microconidia
• In-vitro hair Perforation test :- Negative
• Causes tinea capitis.

9. PATHOGENESIS
Tinea Capitis:- Ringworm of scalp and
hair
• Hyphal invasion of skin of scalps
• Spread to the keratinized wall of hair follicle
• Hypha grow downward on nonliving portion
of hair
• As the hair grows upward the hyphae
produce chain of spores that forms a sheath
around hair shaft
• The infection produce dull gray circular itchy
patches.Tinea Corporis:- Ringworm infection of the body(smooth skin)
• Fungal metabolites, Enzymes, Antigens diffuse through the viable
layer of epidermis
• Vesicle formation
• Lesion expand centrifugally and active hyphal growth at periphery.

10. Tinea Manuum:- Ringworm of the
hands.
• Shows red itchy rash, burning,
cracking and scaling
• May be transmitted sexually or via
scratching and touching.
• It typically starts as a small patch than
gradually becomes larger.
Tinea Barbae:- Ringworm of the
beard and moustache.
• Same as tinea capitis.
• Infection occur as a follicular
inflammation.
• Mostly caused by Trichophyton rarely
caused by Microsporum spp.

11. SPECIES NATURAL RESERVOIR RINGWORM INFECTION
Microsporum
audouinii
Anthropophilic
Tinea corporis & Tinea
capitis
Microsporum canis
Zoophilic (Cats and
dogs)
Tinea corporis,Tinea
capitis,Tinea mannum,
Tinea barbae
Microsporum
ferrugineum
Anthropophilic
Tinea capitis
Microsporum
gypseum
Geophilic (also isolated
from fur of rodents)
Tinea corporis & Tinea
capitis

12. 1. Nail clipping, skin scrapings, hair placed in a slide than 10-
20%KOH is added with Lactophenol blue stain and examine
the sample with a microscope to determine presence of
hyphae.
2. Wood's lamp examination (ultraviolet light) may be used to
diagnose microsporum spp. that fluoresce.
LABORATORY DIAGNOSIS
Spores of microsporum spp. Impart greenish to
silvery fluorescence when examined under Wood’s
lamp.

13. M. canis :-
Positive
M. auduinii :-
Negative
3. Fungal culture
medium can be used
for positive
identification of the
species i.e.
Sabouraud’s dextrose
Agar(SDA).
4. In-vitro hair
perforation Test :
Placing an organism
in a petri-dish with
water, yeast extract
and hair sample.
TREATMENT
General Antifungal medications can be used to treat microsporum
(ringworm) infections,
• Topical medications :- clotrimazole, miconazole, econazole
and terbinafine.
• Oral medications :- Ketaconazole, griseofulvin, terbinafine, and
itraconazole.

14. THANKING YOU