Systemic fungi

• normal habitat: soil
• can cause pulmonary infection when inhaled

Blastomyces dermatitidis

Blastomyces dermatitidis tissue section

Blastomyces dermatidis mycelial phase

Conidia wider than pointer 4-5 micrometer

Blastomyces dermatitidis yeast phase (lactophenol blue wet mount)

Yeast wider than pointer 8-20 micrometer

Blastomyces dermatitidis tissue section (Gomori silver stain)

yeast wider than pointer (8-20 micrometer)

Histoplasma capsulatum

Histoplasma capsulation in brain tissue (Gomoro stain)
Magnification 100X

Histoplasma capsulatum in tissue

100X

Histoplasma capsulatum mycelial phase (slide culture wet mount)
8-20micrometer, 400X
note the spiky conidia

Paracoccidioides brasiliensis 

No sexual phase

37 deg C: multiple buds yeast with narrow bases (multinucleate, need sulfur containing aminoa acid)

Disease: Lesions [due to conidia inhalation]

Subclinical (no symptom just flu, nodules & plaques)

Chronic unifocal (adult smoker, whose 1 lung infected)

Chronic multifocal (resemble TB, cough, chest pain, weight loss)

Subjuvenile

AIDS

Distribution:

South, Central America

humid Summer & dry Winter

Rural>>Urban

Clinical disease M>>F

-Estrogen inhibit tranformation of Y to H

-Estrogen bing protein found in cytoplasm

Diagnose:

Skin test

Serological test

 Paracoccidioides brasiliensis yeast phase (lactophenol blue wet mount)
10-60 micrometer
multiple buds with narrow bases

Paracoccidiodes brasiliensis tissue section (Gomori stain)

multiple buds with narrow bases

Agents that cause Mycetoma

granule from Mycetoma (Madura foot)

causative agent: fungus

Coccidiodes immitis

"immitis" = not mild, severe biohazard

18S rRNA
25 deg C: septate hyphae & alternating arthroconidia with disjunctions that lyse [saprophytic that ruptures with wind]

37 deg C: slimy polysaccharide, yeast with large endospores [in host]

Habitat: alkali soil, arid climate (southern Arizona, central California, Southern New Mexico, & west Texas)

Disease: MOST DANGEROUS SYSTEMIC MYCOSES

Acute Coccidiodomycetoma [inhaling the arthroconidia, effect ppl with low immune system]

-endospores germinate in the lungs (rare, but lethal)

-erythema nodusum (red infected lumps)

-Adult M> Adult F (hormomal control)

Chronic cutaneous Coccidiodomycosis

-High risk for: HIV patients, organ transplant, pregnant woman (hormone)

Diagnose:

Skin test

Serological test

Microscopy

Coccidiodes immitis sperule

note the large endospores

Coccidiodes immitis sperule in human lung tissue (Gomori silver stain)

humungus endospores

Coccidioides immitis sperule (KOH mount)

spot the endospore

Artifact: this is fat globule that can be mistaken for sperule or yeast.

Geotrichum mycelia (lactophenol blue wet mount)

Coccidiodes immitis mycelial phase (Lactophenol blue wet mount)

Sporothrix schenckii

• dimorphic
• 22 deg C: fine septate hyphae with cluster of conidia
• 37deg C: elongated yeast cells with cigar-shaped buds (the form when they infect tissues)

Habitat: soil, animal excreta, living or decaying vegetative
Disease: Sporotrichosis [caused by animal bites, rose thorns, insect sting...]
-papule enlarges overdays or weeks
-can persist for years
-does not cure without treatment
-erythematous(redness from inflamation), ulcerated, pus

Sporothrix schenckii yeast phase from a laboratory mouse
smaller than pointer 1-3 micrometer
look for cigar shaped yeast

Sporothrix schenckii yeast phase lactophenol blue wet mount

look for cigar shaped yeast

Sporothrix schenckii mycelial phase (stain of slide culture)

very fine, delicate

smaller than pointer