Cutaneous/systemic Mycoses & Fungus Flashcards
Yeast in cutaneous or systemic mycoses
Sporothrix schenckii
Hyphae cutaneous to systemic mycoses
Mucormycetes
Pigmented fungi
Oomycetes (not fungus)
Algae cutaneous to systemic mycoses
Prototheca spp (also not a fungus)
Lesions look like fungal infection
Sporotrichosis
Dimorphic fungus
Found in soil/dead vegetation, rose thorns, “rose growers disease” common in cat nails
Sporotrichosis infection and form
Cats*, dogs, horses, humans
Abrasion/puncture - needs traumatized skin
Forms: cutaneous, lymphocutaneous, systemic
Sporotrichosis lesion
Mass like effect, ulceration on skin, development of draining tracts, conjunctival sporotrichosis
Sporotrichosis DX
Cytology - small oval yeast in macrophages (can look like histoplasma)
Culture
Histo pathology
TX for sporotrichosis
Azole drugs
Iodide drugs (dogs only)
Prognosis & public health for sporotrichosis
Good if localized to skin, guarded if disseminated
True zoonotic fungi - ppl can be infected
Mucormycosis
Caused by the murcorales - many organisms live in decaying plant matter
- mucor, rhizopus, lichtheimia, basidobolus, conidiobolus
Formerly called zygomycosis
Found in tropics/subtopics
Type of fungi mucormycosis
Opportunistic and uncommon
Occur in immunosuppressed or otherwise compromised patients
Common in dogs, ruminants (in the rumen) & EQ
Lesions with mucormycosis
Lesions on palette in mouths - secondary to trauma
Ulceration, nodules, draining tracts
DX and TX for mucormycosis
Cytology, culture, histo path
Surgery - radical excision
Azole drugs, amp B, taper immun suppressive drugs
Prognosis is guarded esp if invasion beyond skin
Phaeohyphomycosis
Pigmented fungi
Produce melanin - bipolaris, exophiala, curvularia
Phaeohyphomycosis - infection
Opportunistic and uncommon
Habitat is ubiquitous
Occur in immposouppressed patients, can infect cutaneous, cerebral or disseminated
DX and TX for phaeohyphomycosis
Cytology, histopath, culture
Surgery - excision, azole drugs, amp b, taper steroids
Prognosis is grave
Oomycosis
Not a fungus - Pythiosis. “Swamp cancer”
Fungus like but it lacks chitin, ergosterol and is more related to algae & diatoms
Oomycosis structure and habitat
Warm freshwater, gulf states, rare in va
Requires previous damage to skin for infection
Common in dogs and horses
Infects cutaneous and gastrointestinal forms
Lesions of Oomycosis
Presents like fungal infection
Ulceration, develop draining tract, mass development, granulomas with mass effect
Stomach wall thickening/ulceration
DX of Oomycosis
Cytology - appear w hyphal like structures
Culture, histopath
Serology - detect antibodies to Pythium, helpful for GI form, not necessary for cutaneous infection
TX for Oomycosis
Surgery - aggressive treatment
Azole drugs - not ideal
Amp b
Vaccine is autogenous, works in acute cases, common practice in horses & people
Prognosis is grave, recurrence is common
Protothecosis
Not a fungus - algae
Ubiquitous in aquatic environments
Opportunistic pathogens
Common in dogs, horses, cats, ruminants
Forms of protothecosis
Cutaneous
GIT
Disseminated (esp ocular)
Animals can present for vision problems, chronic diarrhea, skin lesions
Protothecosis uveitis
Detached retina
Inflammation
Enter the eye hematogenous lay
DX or TX for protothecosis
Cytology, culture, histopath
Surgery - often radical,
azole drugs - itraconazole, Amp b
Prognosis is grave
Can spread to humans in unpasteurized milk
