Post on 12-Dec-2015
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SUBCUTANEOUS & SYSTEMIC MYCOSES SUBCUTANEOUS & SYSTEMIC MYCOSES MYCOLOGY AND VIROLOGY | LECTURE
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Lymphocutaneous sporotrichosis showing more advanced, ulcerating lesions developing along the lymph system of the forearm.
Fixed cutaneous verrucous-type sporotrichosis of the wrist and hand
Microscopic morphology of the saprophytic or mycelial form of Sporothrix schenckii when grown on Sabouraud's dextrose agar at 25oC. Note the daisy-like microconidia
Microscopic morphology of the parasitic or yeast form of Sporothrix schenckii when grown on brain heart infusion agar containing blood and incubated at 370C. Note budding yeast cells.
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Sporothrix schenckii on Sabouraud's dextrose agar grown at 25oC colonies are moist and glabrous, with a wrinkled and folded surface. Pigmentation may vary from white to cream to black
Subcutaneous Mycoses } Involve the deeper layers of the skin, including the cornea,
muscle, and connective tissue } Caused by saprophytic fungi that lives on soil or on
vegetation } Occurs by direct implantation of spores or mycelia fragments
into a puncture wound in the skin } The host immune system recognizes the fungi, resulting in
variable tissue destruction and frequently epitheliomatous hyperplasia
} Tend to remain localized and rarely disseminate systemically } Types of Subcutaneous Mycoses:
c Sporotrichosis c Chromomycosis c Mycetoma c Rhinosporidiosis c Lobomycosis c Entomophthoromycosis
SPOROTICHOSIS
} ‘Rose gardener’s disease’ ê Thorns of roses would inoculate the spores
} Classic infection is associated with traumatic inoculation of soil or vegetable or organic matter contaminated with the fungus
} Chronic mycotic infection of the cutaneous or subcutaneous tissues and adjacent lymphatics characterized by nodular lesions which may suppurate and ulcerate
} Occasionally involve the CNS, lungs (Pulmonary sporothricosis) or genitourinary tract
} ETIOLOGIC AGENT: ê Sporothrix schenkii ê Thrives on vegetation ê Dimorphic fungi
� Ambient temp= MOLD � In vitro or tissue @ 35°C - 37°C= small
budding YEAST ê Grows in soil and decaying vegetation
} PATHOGENESIS & CLINICAL FINDINGS: ê Trauma to the skin introduces the conidia or hyphal
fragments ê Initial lesion usually on the lower extremities
� Can also be anywhere � In children, often with facial lesions
} Fixed Sporotrichosis ê Single nonlymphangitic nodule ê Limited and less progressive ê Endemic areas where there is high immunity
level } Lymphocutaneous sporotrichosis
ê Initial lesion develops as a granulomatous nodule that may progress to form a necrotic or ulcerative lesion
ê Multiple subcutaneous nodules and abscesses ê Occur along the lymphatics.
} LABORATORY DIAGNOSIS ê Specimens
� Specimens include biopsy material or exudate from granulous or ulcerative lesions.
ê Microscopic Examination � Sensitivity can be enhanced by
Gomori's and periodic acid-Schiff stain � Mold – flowerette or daisy-like conidia � Yeast – cigar-shaped yeast cell � Asteroid body
Often seen in tissue Consists of a central basophilic
yeast cell surrounded by radiating extensions of eosinophilic material, which are depositions of antigen- antibody complexes and complement
ê Culture � Most reliable method of diagnosis � Specimens are streaked on inhibitory
mold agar or Sabouraud's agar containing antibacterial antibiotics and incubated at 25-30 °C
� The identification is confirmed by growth at 35°C and conversion to the yeast form.
} TREATMENT ê Ocassionally self-limiting ê Oral administration of saturate solution of
Potassium Iodide in milk ê Oral itraconazole or other azoles
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SUBCUTANEOUS & SYSTEMIC MYCOSES SUBCUTANEOUS & SYSTEMIC MYCOSES MYCOLOGY AND VIROLOGY | LECTURE
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Skin scrapings from a patient with chromoblastomycosis mounted in 10% KOH and Parker ink solution showing characteristic brown pigmented, planate-dividing, rounded sclerotic bodies
Chronic verrucose chromoblastomycosis of the foot due to Phialophora verrucosa. Note tissue hyperplasia characterized by the formation of verrucoid, warty cutaneous nodules raised 1 to 3 cm above the skin surface
Phialophora)type)
Phialophora verrucosa • flask-shaped or elliptical
phialides with flaring collarettes
• phialospores on top of the phialide
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phialide
phialospores
Cladosporium,type,
CHROMOMYCOSIS/CHROMOBLASTOMYCOSIS } Mycotic infection characterized by the development in tissue
of dematiaceous (brown-pigmented), planate-dividing, rounded sclerotic bodies (also called Muriform or Medlar bodies)
} Occurs mainly in tropics, usually observed on legs of barefooted agrarian workers
} ETIOLOGIC AGENTS
ê Phialophora verrucosa ê Fonsecaea pedrosoi ê Rhiniocladiella aquaspersa ê Fonsecaea compacta ê Cladosporium carrionii ê All dematiaceous ê Grow on woody plants and in the soil
} PATHOGENESIS & CLINICAL FINDINGS ê Agents often gain entry into the human body by
contact with wood splinters or thorns. ê Early lesions are small, warty papules and ê Usually enlarge only slowly. ê Over years lesions become crusted, verrucose,
wart-like with extension along the draining lymphatics
ê Cauliflower-like nodules with crusting abscesses eventually cover the area
} LABORATORY DIAGNOSIS ê clinical presentation histopathologic findings of
chestnut-brown, sclerotic bodies } CULTURE
ê Slow growing ê Suede like ê Olive black in color
} MICROSCOPIC MORPHOLOGY ê Microscopic Morphology ê Species can be differentiated by studying the
types of sporulation: ê Cladosporium – conidia in branching chain
formation ê Phialophora - production of vase or flask-shaped
conidiophore ê Acrotheca – conidia surrounding the swollen,
knotted, club-shaped terminal ends of hyphae
ê Phialophora verrucosa � Phialophora type
ê Cladosporium carrionii � Cladosporium
ê Rhinocladiella aquaspersa � Acrotheca type
ê Fonsecaea pedrosoi � acrotheca type
ê Fonsecaea compacta � May exhibit all 3 types of sporulation � Smaller conidia and more compact than
F. pedrosoi Phialophora type ª Phialophora verrucosa
§ Flask-shaped or elliptical phialides with flaring collarettes
§ Phialospores on top of the phialide
Cladosporium type ª Cladosporium carrionii
Acrotheca type ª Rhinocladiella aquaspersa ª Fonseceae pedrosoi ª Fonseceae compacta
� May exhibit all 3 types of conidiation
} TREATMENT ê itraconazole and terbinafine ê Because of the risk of recurrences developing
within the scar, surgery is not indicated
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SUBCUTANEOUS & SYSTEMIC MYCOSES SUBCUTANEOUS & SYSTEMIC MYCOSES MYCOLOGY AND VIROLOGY | LECTURE
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Mycetoma)
• Human & animal infection characterized by: ▫ draining sinuses ▫ granules vary in ! Size ! color ! hardness
Grains of Madurella mycetomatis (tissue microcolonies) are brown or black, 0.5 to 1.0 mm in size, round or lobed, hard and brittle, composed of hyphae which are 2 to 5 um in diameter, with terminal cells expanded to 12 to 15 (30) um in diameter
subcutaneous
Mycetomaa)
• etiologic agents ▫ EUMYCOTIC MYCETOMA
• Curvularia
www2.truman.edu
www.dehs.umn.edu
www.mold.ph
subcutaneous
Mycetoma)
www.biologie.uni-halle.de
• Etiologic agents • EUMYCOTIC MYCETOMA
▫ Leptosphaeria
subcutaneous
www.medicine.cmu.ac.th
Mycetoma)
• Etiologic agents
▫ EUMYCOTIC MYCETOMA
• Pseudallescheria
MYCETOMA } Human & animal infection characterized by:
ê Draining sinuses ê Granules vary in
-Size -Color
-Hardness
ê caused by traumatic implantation of spores ê involves cutaneous & subcutaneous tissues, fascia &
bone of foot or hand } ETIOLOGIC AGENTS:
ê Actinomycotic mycetoma (caused by bacteria): ¶ Nocardia ¶ Actinomadura ¶ Streptomyces
ê Eumycotic mycetoma (caused by fungi): ¶ Madurella ¶ Acremonium ¶ Pseudallescheria ¶ Exophiala ¶ Leptosphaeria ¶ Curvularia ¶ Fusarium ¶ Aspergillus
} PATHOGENESIS & CLINICAL FINDINGS ê The earliest lesion is a small, painless,
subcutaneous nodule or plaque that increases slowly but progressively in size
ê As the mycetoma develops,the affected area gradually enlarges and becomes disfigured as a result of chronic inflammation and fibrosis.
ê With time, sinus tracts appear on the skin surface and drain serosanguineous fluid that often contains grossly visible granules.
ê The infection commonly breaches tissue planes and destroys muscle and bone locally
} LABORATORY DIAGNOSIS ê Key to the diagnosis of eumycotic mycetoma is the
demonstration of grains or granules ê Grains can be visualized microscopically by
mounting in 20% KOH. ê Grains are easily visualized in tissue stained with
H&E ê Culture is usually necessary for definitive
identification of the organism.
} ETIOLOGIC AGENTS: r Eumycotic mycetoma
ê Curvularia
ê Leptosphaeria
ê Pseudallescheria
ê Aspergillus
} TREATMENT
ê Response to amphotericin B, ketoconazole, or itraconazole is variable and often poor, although such therapy may slow the course of infection
ê Promising treatment responses have recently been reported for terbinafine, voriconazole, and posaconazole
ê Local excision is usually ineffective or not possible, and amputation is the only definitive treatment
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• Mature spherule with endospores typical of rhinosporidiosis.
Lobomycosis showing extensive verrucoid lesions on the legs
• Grocott’s methenamine silver (GMS) stained tissue section showing numerous darkly pigmented yeast-like cells, often in chains, 9-12 um in size typical of Loboa loboi.
Entomophthoromycosis caused by Basidiobolus ranarum showing an ulcerated subcutaneous lesions on the abdomen of a young boy from Darwin.
Entomophthoromycosis caused by Basidiobolus ranarum showing a subcutaneous lesion involving the entire thigh and buttock of an Indonesian boy.
Haematoxylin and eosin (H&E) stained section of tissue from a lesion on a child's arm showing broad septate hyphae surrounded by an eosinophilic sheath (Splenodore-Hoeppli phenomenon) typical of Entomophthoromycosis
• Microscopic morphology of Basidiobolus ranarum showing numerous round, smooth, thick-walled zygospores
Entomophthoromycosis caused by Conidiobolus coronatus in a patient seen at the Pasteur Institute in Paris in 1972 from the then French Camaroons. Note the massive swelling and distortion of the subcutaneous tissue of the nasal and perioral regions, with a large polypoid protrusion on the inner aspect of the lower lip.
• Microscopic morphology of Conidiobolus coronatus showing several mature, spherical sporangiola (conidia) with hair-like appendages, called villae and prominent papillae, marking the site of former attachment to the sporangiophore.
RHINOSPORIDIOSIS } Is an infection of the mucocutaneous tissue caused by
Rhinosporidium seeberi } Causes a chronic granulomatous disease characterised by
the production of large polyps, tumours, papillomas, or wart-like lesions.
} The nose is the most commonly affected site.
LOBOMYCOSIS } Chronic, localised, subepidermal infection } Keloidal, verrucoid, nodular lesions or vegetating crusty
plaques and tumours } Loboa loboi - masses of spheroidal, yeast-like organisms in
lesions } Cauliflower-like and hyper or hypopigmented } Etiologic agent known as "Loboa loboi" } PATHOGENESIS AND CLINICAL FINDINGS
ê The initial infection is thought to be caused by traumatic implantation
ê The lesions begin as small, hard nodules resembling keloids and may spread slowly in the dermis and continue to develop over a period of many years.
ê Older lesions become verrucoid and may ulcerate. ê The disease may be transferred to other areas of
the skin by further trauma or autoinoculation. ê 90% of cases are men, mostly in farmers and
other high- risk groups exposed to various harsh conditions as well as aquatic habitats
} CONTROL ê Wide surgical excision of the affected area ê Clofazimine ê Slow and chronic and the although not life
threatening the prognosis is poor.
ENTOMOPHTHORMYCOSIS } Also known as Subcutaneous zygomycosis } Etiologic agents:
¶ Conidiobolus coronatus (upper part of the body, face)
¶ Basidiobolus ranarum (lower, legs) } Entomophthoromycosis caused by Basidiobolus } Chronic inflammatory or granulomatous disease generally
restricted to the limbs, chest, back or buttocks } Primarily occurring in children with predominance in males. } Initially, lesions appear as subcutaneous nodules, which
develop into massive, firm, indurated, painless swellings, which are freely movable over the underlying muscle but are attached to the skin which is hyperpigmented but not ulcerated.
} Etiologic Agent: ¶ Basidiobolus ranarum (= B. haptosporus)
commonly present in decaying fruit and vegetable matter, and as a commensal in the intestinal tract of frogs, toads and lizards.
} Entomophthoromycosis caused by Conidiobolus } A chronic inflammatory or granulomatous disease that is
typically restricted to the nasal submucosa and characterized by polyps or palpable restricted subcutaneous masses.
} Human infections occur mainly in adults with a predominance in males (80% of cases).
} Distribution: Worldwide, especially tropical rain forests of Africa.
} Aetiological Agent: Conidiobolus coronatus, commonly present in soil and decaying leaves.
} Laboratory Diagnosis ê Both types of subcutaneous zygomycosis require
biopsy for diagnosis ê Morphology: Short, poorly stained hyphal
fragments, surrounded by eosinophilic Splendore-Hoeppli material
} Treatment: ê Both types of infection may be treated with
itraconazole. ê Facial reconstructive surgery may be necessary ê in the case of C. Coronatus infection
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Histoplasmosis of the lower gum showing ulcer around base of tooth.
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Microscopic morphology of the saprophytic or mycelial form of Histoplasma capsulatum showing characteristic large, rounded, single-celled, tuberculate (with spike-like projection) macroconidia formed on short, hyaline, undifferentiated conidiophores.
323
Tissue section stained with haematoxylin and eosin (H&E) from a biopsy of the mouth lesion shown in slide 7. Note macrophages containing numerous yeast cells of Histoplasma capsulatum
329
Microscopic morphology of the parasitic or yeast form of Histoplasma capsulatum cultured on brain heart infusion agar containing blood incubated at 37oC. Note the small round to oval budding yeast-like cells.
325
Culture of Histoplasma capsulatum on Sabouraud's dextrose agar showing a white suede-like colony with a pale yellow-brown reverse.
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Culture of Histoplasma capsulatum on Sabouraud's dextrose agar showing a pale yellow- brown reverse.
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exoantigen immunodiffusion test kit for the identification of Histoplasma capsulatum
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Exoantigen immunodiffusion plate showing positive identification of Histoplasma capsulatum. Note H and M bands of identification; EX = culture filtrate; H = Histoplasma antibody and antigen, C = Coccidioides antibody and antigen; B = Blastomyces antibody and antigen.
Systemic Mycoses } Deep w/in the body } Caused by fungi that live in the soil } Typically begins in the lungs then spread to other body
tissue } Not contagious } Types of Systemic Mycoses:
¶ Histoplasmosis ¶ Coccidiodomycosis ¶ Blastomycosis ¶ Paracoccidiomycosis
HISTOPLASMOSIS
} Also known as Cave disease, Darling's disease, Ohio valley disease, Spelunker’s Lung and Caver's disease
} Intracellular mycotic infection of the reticuloendothelial system caused by the inhalation of the fungus
} Approximately 95% of cases of histoplasmosis are inapparent, subclinical or benign.
} Five percent of the cases have chronic progressive lung disease, chronic cutaneous or systemic disease or an acute fulminating fatal systemic disease
} All stages of this disease may mimic tuberculosis. } Distribution: World-wide, especially U.S.A. Sporadic cases
do occur in Australia. } Aetiological Agent: Histoplasma capsulatum, especially
from soil enriched with excreta from chicken, starlings and bats.
} Laboratory Diagnosis: ê Specimen: Sputum, bronchoalveolar lavage (BAL)
, blood, bone marrow, tissue ê Morphology in Culture
¶ Room Temp (25°C); Saprobic phase - Mold with tuberculate macroconidia and small, oval microconidia
¶ Body Temp (37°C); parasitic phase – Small budding yeast
ê Serology ¶ Antibody: complement fixation,
Immunodiffusion ¶ Antigen: serum and urine
COCCIDIOMYCOSIS
} Commonly known as San Joaquin Valley fever } Initially, a respiratory infection, resulting from the inhalation
of conidia, that typically resolves rapidly leaving the patient with a strong specific immunity to re-infection
} Sometimes the disease may progress to a chronic pulmonary condition or as a systemic disease involving the meninges, bones, joints and subcutaneous and cutaneous tissues.
} Distribution: endemic in south-western USA, Northern Mexico and various centres in South America
} Aetiological Agent: Coccidioides immitis, a soil inhabiting fungus considered as the most virulent of all human mycotic pathogens; major biohazard to laboratory personnel
} Laboratory Diagnosis: ê Specimen: Sputum, bronchoalveolar lavage (BAL)
, tissue ê Morphology in Culture
¶ Room Temp (25°C); Saprobic phase - Mold with barrel-shaped arthroconidia
¶ Body Temp (37°C); parasitic phase – Spherul containing endospores
ê Serology ¶ Antibody: complement fixation,
Immunodiffusion, tube precipitin, latex particle agglutination
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SUBCUTANEOUS & SYSTEMIC MYCOSES SUBCUTANEOUS & SYSTEMIC MYCOSES MYCOLOGY AND VIROLOGY | LECTURE
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Ulcerated granuloma due to B. dermatitidis.
051
Cutaneous blastomycosis of 20 years duration showing loss of skin.
Cutaneous blastomycosis from the same patient as in slide 31 showing loss of skin from the arm and fingers.
Blastomyces dermatitidis mold phase.
Giemsa stain of Blastomyces dermatitidis showing broad-based budding yeast
Coccidioidomycosis showing chronic lesions of the face. Active lesions are seen on the cheek. An atrophic, depigmented scar representing a healed lesion is on the forehead.
Chronic cutaneous coccidioidomycosis showing granulomatous lesions on face, neck and chin
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Extension of pulmonary coccidioidomycosis showing a large superficial, ulcerated plaque.
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Microscopic morphology of Coccidioides immitis showing typical single-celled, hyaline, rectangular to barrel-shaped, alternate arthroconidia, separated from each other by a disjunction cell.
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Microscopic morphology of Coccidioides immitis showing typical single-celled, hyaline, rectangular to barrel-shaped, alternate arthroconidia, separated from each other by a disjunction cell
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Direct microscopy of skin scrapings from a cutaneous lesion mounted in 10% KOH characteristic endosporulating spherules
The presence of spherules with endospores is and Parker ink solution showing (sporangia) of Coccidioides immitis. diagnostic.
109
Periodic Acid-Schiff (PAS) stained tissue section of viscera from an experimentally induced infection in a mouse showing typical endosporulating spherules of Coccidioides immitis. Young spherules have a clear centre with peripheral cytoplasm and a prominent thick wall. Endospores (sporangiospores) are later formed within the spherule by repeated cytoplasmic cleavage. Rupture of the spherule releases endospores into the surrounding tissue where they re-initiate the cycle of spherule development.
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Culture of Coccidioides immitis on Sabouraud's dextrose agar showing a suede-like to downy, greyish white colony
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Culture of Coccidioides immitis on Sabouraud's dextrose agar showing a tan to brown reverse.
(continuation… Coccidiomycosis)
BLASTOMYCOSIS } Also known as North American Blastomycosis,
Gilchrist’s disease and Chicago disease } Chronic granulomatous and suppurative disease having a
primary pulmonary stage that is frequently followed by dissemination to other body sites, chiefly the skin and bone
} Distribution: North America, some cases from Africa, Asia and Europe.
} Aetiological Agent: Blastomyxes dermatitidis, a soil inhabiting fungus.
} Laboratory Diagnosis ê Specimen: Sputum,BAL, lung, tissue, skin biopsy ê Morphology in Culture
¶ Room Temp (25°C); Saprobic phase - Mold, round to oval or pear-shaped conidia; “lolipop conidia”
¶ Body Temp (37°C); parasitic phase – Broad- based,budding yeast
ê Serology ¶ Antibody: complement fixation,
Immunodiffusion, enzyme immunoassay ¶ Antigen: serum and urine
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SUBCUTANEOUS & SYSTEMIC MYCOSES SUBCUTANEOUS & SYSTEMIC MYCOSES MYCOLOGY AND VIROLOGY | LECTURE
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Mucocutaneous paracoccidioidomycosis showing extensive destruction of facial features.
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Mucocutaneous paracoccidioidomycosis showing an ulcerated lesion on the lips and loss of teeth
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Mucocutaneous paracoccidioidomycosis showing an ulcerated lesion on the pharyngeal mucosa.
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Grocott’s methenamine silver (GMS) stained lung tissue section showing multiple, narrow base, budding yeast cells "steering wheels" of P. brasiliensis.
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Microscopic morphology of Paracoccidioides brasiliensis showing multiple, narrow base, budding yeast cells "steering wheels" of P. brasiliensis
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PARACOCCIDIOIDOMYCOSIS } Also known as South American Blastomycosis } Chronic granulomatous disease that characteristically
produces a primary pulmonary infection, often inapparent, and then disseminates to form ulcerative granulomata of the buccal, nasal and occasionally the gastrointestinal mucosa.
} Distribution: geographically restricted to areas of South and Central America
} Aetiological agent: Paracoccidioides brasiliensis } Laboratory Diagnosis:
ê Specimen: Sputum, bronchoalveolar lavage (BAL), tissue
ê Morphology in Culture ¶ Room Temp (25oC); Saprobic phase -
Mold, round microconidia and intercalary chlamydospores
¶ Body Temp (37oC); parasitic phase - multiple, budding yeast; “steering wheel,” “pilot wheel,” “mariner’s wheel”
ê Serology ¶ Antibody: complement fixation,
Immunodiffusion
**Activities FUNGI DISEASE MOLD FORM TISSUE
FORM Blastomyces dermatitidis
Gilchrist’s disease
Lollipop conidia
Broad base budding yeast
Histoplasma capsulatum
Ohio valley disease
Tuberculate macroconidia
Small budding yeast
Coccidioides immitis
San Joaquin valley fever
Barrel shaped arthroconidia
Spherule with endospores
Paracoccidioides brasiliensis
South American blastomycosis
Round macroconidia
Mariner’s wheel
• REFERENCES: Bailey & Scott's Diagnostic Microbiology 12th Ed • Murray, P eat al. Medical Microbiology 6th Ed.
“Before I formed you in the womb, I knew you, before you were born I set you apart.”
- Jeremiah 1:5