Fungi Flashcards
Microsporum canis
disease association
zoophilic, geophilic or anthrophilic
host
“ringworm”, fungal abscess/kerion
zoophilic
cat is natural host
also occurs in dogs
Microsporum periscolor
zoophilic, geophilic or anthrophilic
host
zoophilic & geophilic
primarily dogs
Microsporum gypsum
zoophilic, geophilic or anthrophilic
host
1 dermatophyte in horses in South
2nd most common dermatophyte in dogs
geophilic
Trichiphyton equinum
zoophilic, geophilic or anthrophilic
host
zoophilic
horses
Trichiphyton mentagrophytes
zoophilic, geophilic or anthrophilic
host
zoophilic
horses, sometime dogs
reservoir: wild rodents
Trichiphyton verruscosum
zoophilic, geophilic or anthrophilic
host
zoophilic
cattle
Microsporum nanum
zoophilic, geophilic or anthrophilic
host
zoophilic
pigs
Epidermophyton spp.
disease association
zoophilic, geophilic or anthropophilic
host
“athelete’s foot”
anthropophilic
humans
Microsporum audouinii
disease association
zoophilic, geophilic or anthrophilic
host
tinea capitis in children
anthropophilic
humans
diagnostics for dermatophytosis
wood’s lamp
experience
culture on dermatophyte test medium (DTM) or Sabouraud’s Agar
KOH prep on crusts/hair
wavelength of UV light of wood’s lamp
320-400 nm
shortcomings of using wood lamp for dermatophytosis
false - from non-fluorescing strains or a cold lamp
false + from ointments, dead skin or Pseudomonas spp.
shortcomings of DTM for dermatophytosis
false + possible
when is it necessary to include a histopathological evaluation in cases of suspected fungal disease?
for common contaminants
e.g. zygomyces
organisms that exhibit dimorphism and is it thermal or tissue dimorphism?
Sporothrix schenckii (thermal)
Blastomycosis (thermal)
Histoplasma capsulatum (thermal)
Coccidiodes immitis (tissue)
Sporothrix schenckii yeast appearance
intralesional yeast “cigar bodies”
zoonotic fungi
Microsporum canis
Sporothrix schenckii
diagnostic methods for dimorphic systemic mycoses
Blastomyces dermatitidis
- galactomannan Ag in urine
- brain heart infusion agar w/ cycloheximidde & chloramphenicol
Histoplasma capsulatum
- urine Ag test
Coccidioides immitis
- anti-CI Ab
Malassezia pachydermatitis
common in vetmed
YEAST
ear infections
no culture – cyto or clinically fine
Sporothrix schenkii (sporotrichosis)
host
disease
horses, dogs, cats, people
“rose-picker’s disease”, non-healing wounds on head, neck, extremities
Pythium indidiosum (pythiosis)
host
disease
geographic distribution
horses, dog, humans
(oomycosis) - osteomyelitis “swamp cancer” “leeches”, non-healing granulomas
stagnant water in tropical regions
Basidiobolus spp.
zygomycosis
Mucor and Rhizopus spp.
disease
host
zygomycosis
mucormycosis most common form
immunocompromised patients, predilection for Tasmanian platypus
Candida albicans
opportunistic systemic mycoses - yeast (narrow base)
mouth, bladder, kidney, peritonitis, crop mycosis in birds
Aspergillus fumigatus
host
disease
horses (common), then dogs
immunosuppression not required
mycetomas (fungal maasses) in guttural pouch or nose
A. fumigatus & Mucor spp.
host
disease
cattle
mycotic abortion
Pseudallescheria boydii
host
disease
differential for canine nasal aspergillus or in mesentary
cow - granulomatous rhinitis & sinusitis
Aspergillus spp, Fusarium spp, Alternaria spp.
host
disease
mycotic keratitis in horses and dogs
Cryptococcus neoformans
host
disease
pathogenesis
cats, dogs, humans
space occupying lesions - resp, skin, CNS, eye
enriched pigeon droppins “creatinine”
C. neoformans gattii
host
disease
geographic distribution
cats, dogs, humans
space occupying lesions - resp, skin, CNS, eye
Pacific NW horses
Blastomycosis geographic distribution
Eastern, Midwest, acidic/moist soil like near the Mississippi/ Ohio River Valley
Blastomycosis yeast characteristics
at body temp
broad based budding
Blastomyces dermatitidis
host
disease
dogs, humans
pyogranulomatous inflam - lungs then bone, CNS, eye, skin
Histoplasma capsulatum geographic distribution
Midwest/Southcentral, esp. Ohio/Mississippi River Valley
bird/bat droppings
Histoplasma capsulatum yeast characteristics
macrophages
capsule deficient crypto
Histoplasma capsulatum
host
disease
cats, dogs, humans
lung then spreads to SI, liver, LN, spleen, eye, rarely bone; wasting syndrome
Coccidiodes immitis geographic distribution
lower Sonoran life zones (cacti zones) w/ alkaline soil
SW US ( AZ, NM)
some CA, WA
Coccidiodes immitis yeast characteristics
“arthroconidia” - arthrospores, spherule with endospores
Coccidiodes immitis
host
disease
dogs, camelids
Valley Fever