Others important fungi are included in this group Histoplasma capsulatum Blastomyces dermatitidis Paracoccidioides barasiliensis Coccidioides immitis Cryptococcus neoformans

1. Mycotic zoonosesDr. Ripan Biswas
Assistant Professor
Department of Veterinary public Health
West Bengal University of Animal & Fishery Sciences

2. • Fungi are eukaryotic,
•Cell walls similar in structure to plants but vary in
chemical composition
• Chitin, glucan, mannan
•Thallus (body)
• unicellular (yeasts) or multi-cellular (molds)
•Mycelium (molds)
• loosely organized mass of filamentous hyphae

3. The Characteristics of Fungi
• Body form
Unicellular yeast
Multicellular mold
• filamentous (tube-like
strands called hypha
(singular) or hyphae
(plural)
• mycelium = aggregate of
hyphae
• sclerotium = hardened
mass of mycelium that
generally serves as an
overwintering stage.
• multicellular, such as
mycelial cords,
rhizomorphs, and fruit
bodies (mushrooms)

4. mycelium
fruiting bodies
both are
composed
of hyphae

5. Hypha
Septate vs Coenocytic (Nonseptate)

6. The Characteristics of Fungi
• Heterotrophy - 'other food'
•Saprophytes or saprobes - feed on dead
tissues or organic waste (decomposers)
•Symbionts - mutually beneficial relationship
between a fungus and another organism
•Parasites - feeding on living tissue of a host.
•Parasites that cause disease are called
pathogens.

7. Heterotrophic by Absorption
•Fungi get carbon from organic sources
•Hyphal tips release enzymes
•Enzymatic breakdown of substrate
•Products diffuse back into hyphae
Product diffuses back
into hypha and is used
Nucleus hangs back
and “directs”

8. Hyphal growth
• Hyphae grow from their tips
• Mycelium = extensive, feeding web of hyphae
• Mycelia are the ecologically active bodies of fungi
This wall is rigid Only the tip wall is plastic and stretches

9. Modifications of hyphae

10. Hyphal growth from spore
• Mycelia have a huge surface area
mycelium
germinating
spore

11. Mycotic zoonoses
Superficial
mycoses
outermost
layer of the
skin and hair
Tinea versicolor, Piedraia
hortae
White
piedra
Cutaneous
mycoses
Cutaneous
tissue/
Epidermis
Microsporum &
Trichophyton
Ring worm lesion
Sub-
cutaneous
mycoses
Sub-
cutaneous
Rhinosporidium seeberi,
Sporothrix (Sporotrichum)
schenckii
rose gardener's
disease
Systemic
mycoses
Lung Aspergillosis
Blastomycosis
Candidiasis
Cryptococcosis
Histoplasmosis
zygomycosis

12. Dermatophytes/ Tinea/ Ringworm
Trichophyton Microsporum Epidermophyton
Trichophyton verrucosum M. Canis Epidermophyton floccosum
T. mentagrophytes var.
interdigitalis
M. nanum Epidermophyton stockdaleae
T. tonsurans M. gypseum
T. Equinum T. tonsurans
Dermato-Skin
Phyt (on)-plant that grows>>>>>>>>plant that grows on the skin

13. Anthrophilic Zoophilic Geophilic
Epidermophyton
floccosum
M. Canis M. gypseum
T. rubrum T. verrucosum M. nanum
M. audouinii M. distortum M. cookei
T. mentagrophytes
var. interdigitalis
T. Equinum T. ajelloi
T. tonsurans M. gallinae T. simii

14. Microsporum : Hypae produce chain of spores forming sheath around
the hair shaft- ectothrix
Trichophyton : hypae produce spores within the hair
shaft – endothrix
Hair become weakened; typically break easily at the follicle opening

15. Tinea capitis : infection in scalp and hair >>>Trichophyton or
Microsporum
Tinea barbae : infection in beard area
Tinea corporis : infection in the trunk
Tinea cruris (jock itch): infection in groin/ inguinal region
Tinea manum : infection in hand
Tinea pedis (athlete’s foot) : infection in foot

16. Laboratory diagnosis
•
1. Skin : from the margin of the lesion, with the scalpel.
2. Nail : deeper part is collected and superficial part is discarded.
3. Hair : plucked by fine forceps.

17. Wood’s lamp test
Ectothrix of Microsporum species impart a greenish to silvery
fluerescence when examined under Wood’s light

18. Microscopic examination
KOH preparation of skin or nail : branching hypae or chains of
arthoconidia are seen
Unstained microscopic
KOH prep. of scraping from
a ring worm showing
arthrospore (asexual spores)

19. Multicellular macroconidia of
M. canis
Club shaped macroconidia with thin and
smooth wall arise in small clusters of E.
floccosum
Elongated microconidia of
T. tonsurans

20. KOH preparation of hair : ectothrix and endothrix are seen
ectothrix (arthospore outside hair shaft)
endothrix (arthospore inside hair shaft

21. • Culture :
- Incubation period : 1-3 weeks.
- Incubation temparature : 25˚ C.
- Media used :
1. Sabouraud’s dextrose agar media.
2. Dermatophyte test media : Sabouraud’s dextrose agar +
cyclohexamide + chloramphenicol + phenol red.
3. Malt agar.

22. T. tonsurans : flat, powdery, velvety colony
Epidermophyton-
flat, velvety
with a tan to
olive green tinge

23. PCR : species specific identification

24. Systemic Mycotic
Zoonoses

25. Aspergillosis
Aspergillus is a ubiquitous genus of mould that is commonly found in
soil and decaying vegetation
Aspergillus fumigatus most commonly found species-90%
Other species that can cause human disease include Aspergillus flavus,
Aspergillus terreus and Aspergillus niger
Aspergillosis is not contagious
Aspergillus cannot be transmitted from person to person

26. In outdoor environments-
Soil
Compost heaps
Damp grain
Inside buildings
Damp insulation
Fireproofing material
Bedding
Behind sofas
In the corner of damp rooms
Dust
Air conditioning systems
Farmer’s Lung Disease
Hay
Animal feed

27. Invasive pulmonary aspergillosis (IPA)
Fever
Pleuritic chest pain
Haemoptysis (coughing up blood)
Cough and shortness of breath
Treatment
Voriconazole is recommended as first-line therapy for IPA
Chronic pulmonary aspergillosis (CPA)
Allergic bronchopulmonary aspergillosis
Aspergillus rhinosinusitis

28. Invasive aspergillosis •Voriconazole
•Amphotericin B
•Isavuconazole
•Posaconazole
•Echinocandins
Chronic pulmonary
aspergillosis
•Itraconazole
•Voriconazole
•Posaconazole
•Isavuconazole
•Amphotericin B
•Echinocandins
Allergic
bronchopulmonary
aspergillosis
•Corticosteroids
•Itraconazole
•Voriconazole
•Nebulised amphotericin
B
Aspergillus bronchitis
•Itraconazole
•Voriconazole
•Nebulised amphotericin
B

29. Others important fungi are included in this group
1. Histoplasma capsulatum
2. Blastomyces dermatitidis
3. Paracoccidioides barasiliensis
4. Coccidioides immitis
5. Cryptococcus neoformans
Four of these pathogens are dimorphic-
1. H. Capsulatum
2. B dermatitidis
3. P. Barasiliensis
4. C. immitis
They grow as filamentous molds
as saprobes and in culture at 25 ﾟC
when they infect humans or are
cultured at 37 ﾟC
they transform to a unicellular
morphology.

31. Histoplasmosis
Also known as Darling's disease
 Acute pulmonary>>>>>>> "flu-like"
 Chronic pulmonary/ Disseminated>>>>>if untreated>>> The
sputum may be purulent or bloody
All are endemic to
certain geographical
areas where they can
usually be found in
the soil.

32. BLASTOMYCOSIS (Blastomyces dermatitidis)
Amphotericin
B remains is
the drug of
choice (DOC)
although it is
very toxic and
must be
administered
intravenously
for several
weeks.
Ketoconazole
is also being
used in mild
cases
Gilchrist Disease

33. Coccidioides immitis
Valley Fever/ California Disease

34. Desert soil, pottery, archaeological middens, cotton, and rodent
burrows all harbor C. immitis.
C. immitis is a dimorphic fungus with 2 life cycles. The
organism follows the SAPROPHYTIC cycle in the soil and
the PARASITIC cycle in man or animals

41. Thanks to all of my
students to listen
attentively