SUBCUTANEOUS MYCOSES Flashcards
Subcutaneous mycoses
a. Mycetoma
b. Chromoblastomycosis
c. Phaeohyphomycosis
d. Sporotrichosis
chronic granulomatous infection that usually involves the lower extremities
Mycetoma
infection is characterized by swelling, purplish discoloration, tumor-like deformities of the subcutaneous tissue, and multiple sinus tracts that drain purulent material containing yellow, white, red, or black granules called ______
Mycetoma
Grains
The infection gradually progresses to involve the bone, muscle, or other contiguous tissue and ultimately requires amputation in most progressive cases
Mycetoma
Mycetomas usually are seen among people living in
Tropical and subtropical regions
Mycetoma The organisms associated with mycetoma are saprophytic and commonly found in
Soil, standing water and sewage
humans acquire infections through traumatic implantation of the organism into the skin and subcutaneous tissues
Mycetoma
Mycetoma Subcutaneous Mycoses
- Two types:
Actinomycotic (bacterial) mycetomas
Eumycotic (fungal) mycetomas
Causes of Actinomycotic mycetomas
Bacteria
caused by the aerobic actinomycetes, including
Nocardia, Actinomadura, and Streptomyces spp.
Caused by a heterogeneous group of fungi that have septate hyphae
Eumycotic (fungal) mycetomas
Eumycotic mycetoma is subcategorized as
white grain mycetomas or black grain mycetomas
is the most common fungal agent associated with mycetoma
Madurella mycetomatis
Mycetoma
Direct examination of clinical specimens from patients with a eumycotic mycetoma or phaeohyphomycosis demonstrates
yellowish brown, septate to moniliform hyphae (string of beads)
White Grain Mycetoma also known as
Scedosporium spp
Initial growth begins as a white, fluffy colony that changes in several weeks to a brownish gray (the so-called mousy gray) colony; the reverse of the colony progresses from tan to dark brown.
Scedosporium spp.
White grain mycetoma
that cause mycetomas, such as Acremonium falciforme, grow slowly and produce gray colonies.
Acremonium spp.
Acremonium spp. that cause mycetomas, such as __________________, grow slowly and produce _____________.
Acremonium falciforme
Gray colonies
Black grain mycetoma
Madurella spp. and E. jeanselmei
Colonies of Madurella spp. vary from white (during the early phases of growth) to ___________________ diffusible pigment is characteristic of this fungus.
olive-brown; a brown
appear yeastlike and darkly pigmented (olive to black) but in time develop a velvety appearance with the production of aerial hyphae
E. jeanselmei
produce a fluffy or downy, olive-gray to black colony, and growth is rapid.
Curvularia spp.
forms slow-growing, velvety colonies that appear smooth or radially furrowed and dark gray or olive-brown to black. The reverse side of the colonies appears black. The hyphae are septate and nonsporulating
T.grisea
chronic fungal infection acquired through traumatic inoculation of an organism, primarily into the skin and subcutaneous tissue
Chromoblastomycosis
Chromoblastomycosis characterized by the development of a papule at the site of the traumatic insult that slowly enlarges to form _______________ characterized as resembling ______________capable of spreading through the _______________
Warty or tumorlike lesion
Cauliflower
Lymphatic system
The lesions usually are confined to the feet and legs but may involve the head, face, neck, and other body surfaces.
Chromoblastomycosis
Chromoblastomycosis
Histologic examination of the lesion reveals characteristic ___________ which are ____________, septate cells that appear to be dividing by binary fission and resemble __________.
Sclerotic bodies
Copper colored
Copper pennies
infections cause hyperplasia of the epidermal layer of the skin, which may be mistaken for squamous cell carcinoma
Chromoblastomycosis
Chromoblastomycosis is widely distributed, but most cases occur in
tropical and subtropical areas
The fungi most often associated with chromoblastomycosis include
Cladophialophora carrionii
Fonsecaea monophora and pedrosoi
Phialophora verrucosa
Chromoblastomycosis Scrapings from crusted lesions added to 10% KOH show ______________________ or _______________ which are rounded, brown, 4 to 10 μm in diameter, and have fission planes. They resemble __________________
Muriform cells (aggregation of dark brown cells that resemble stones in a stonewall)
Sclerotic bodies
Copper pennies
includes species that produce long chains of budding, often fusiform, conidia (blastoconidia) that have a dark septal scar.
Cladosporium
includes species that produce short, flask-shaped to tubular phialides, each with a well-developed collarette
Phialophora
Phialophora
Produce colonies that are__________________________;some strains may appear to have concentric zones of color
wooly and olive-brown to brownish gray
includes organisms that exhibit a mixed type of sporulation
Fonsecaea
produces a distinct Fonsecaea-type conidiophore, may also produce a Rhinocladiella-type sporulation
Fonsecaea
type of sporulation with long chains of elliptical conidia (2 to 3mμm × 4 to 5 μm) borne from erect, tall, branching conidiophores
Cladophialophora (C. carrionii)
produces phialides, each with a distinct cup- or flask-shaped collarette
P. verrucosa
produces phialides with a flattened collarette
P. richardsiae
Conidial heads with sympodial arrangement
of conidia are seen, with primary conidia giving rise to secondary conidia
Fonsecaea spp.
general term used to describe any infection caused by a dematiaceous organism
Phaeohyphomycosis
Phaeohyphomycosis
Includes _______;_____________; _______________; and ____________.
Molds
Brownish Yeastlike cells
Pseudohyphae
Hyphae
These infections may be subcutaneous, localized, or systemic
Phaeohyphomycosis
Include phaeohyphomycotic cysts, progressive soft tissue infection, brain abscess, sinusitis, endocarditis, mycotic keratitis,pulmonary infection, and systemic infection.
Phaeohyphomycosis
Symptoms often include headache, neurologic manifestations, and seizure
Phaeohyphomycosis
Phaeohyphomycosis Subcutaneous Mycoses
- The most common fungal isolates associated with Neurological manifestations
C. bantiana
Rhinocladiella mackenziei
Verruconis gallopava
Exophiala dermatitidis.
Species that are commonly associated with phaeophyomycosis
Alternaria, Exserohilum, Bipolaris, E. jeanselmei, Exophiala spinifera, and Curvularia spp.
colonies are rapidly growing, fluffy, and gray to gray-brown or gray-green.
Alternaria
produce rapidly growing colonies that resemble those of Alternaria spp.
Curvularia
produce colonies that are gray-green to dark brown and slightly powdery, as do Exserohilum spp.
Bipolaris spp.
grow slowly (7 to 21 days) and initially produce shiny, black, yeastlike colonies.
E. jeanselmei and E. dermatitidis
Mycetoma bacterias
Nocardia, Actinomadura, and Streptomyces spp.
White grain Mycetoma
S. apiospermum complex
Acremonium
Fusarium spp.
Black grain mycetoma
Madurella spp.
E. jeanselmei,
Curvularia spp.
Chromoblastomycosis
Cladophialophora
Phialophora,
Fonsecaea spp.
Phaeohyphomycosis
E. jeanselmei
E. dermatitidis
Curvularia
Bipolaris
Alternaria
Exserohilum spp.
is a subcutaneous infection, but lymph and pulmonary infections can occure is a
Sporotrichosis
Also known as rose gardener’s disease, as infections can come from rose thorns and contact with sphagnum moss
Sporotrichosis
Sporotrichosis sppecies that are involved in human infection include
S. schenckii
Sporothrix brasiliensis
Sporothrix globosa
Sporothrix luriei
Sporothrix spp. have a worldwide distribution, and their natural habitat
Living or dead vegetation
Humans acquire the infection (sporotrichosis) through
trauma (thorns, splinters, bites, or scratches), usually to the hand, arm, or leg
- It is a dimorphic fungus
Sporothrix schenckii
When grown on media with blood at 35°C, these fungi grow as small yeasts
Sporothrix schenckii
When grown on SDA or PDA at room temperature, they are in the mould phase characterized by delicate hyphae and microconidia
Sporothrix schenkii
Yeast cells may be seen in segmented neutrophils and are “cigar-shaped”
Sporothrix schenckii
