Mycology Flashcards

Question

***_Cladophialophora carrionii_***

Answer 1

* an agent of chromoblastomycosis phaeohypomycosis * other reported infections include endocarditis, keratitis, and osteomyelitis * Pigmented septate hyphae * **Vase shaped phialides with flared, darker collarettes** * Clusters of conidia

Answer 2

* Sympodial conidia * Conidiophores straight, upright, unbranched, thick walled, and dark brown.

Answer 3

* Fonsecaea pedrosoi * Fonsecaea compacta * dematiaceous (dark/brown) septate and loosely branching hyphae. * conidia produced are pale brown or olivaceous in color * In tissues, it appears as large (5 12 µm diameter), round, brownish * and thick-walled bodies * Can exhibit different morphotypes * Cladosporium type * Phialophora type * Rhinocladiella type * **Conidiophores are long, septate** * Conidia produced from tips of condiophores but also along condiophore * sides and directly from hyphae

Answer 4

* Tinea/Pityriasis versicolor (Malassezia sp.) * Tinea nigra (Hortaea werneckii) * Black piedra (Piedraia hortae) * White piedra (Trichosporon sp.)

Answer 5

* Tinea/Pityriasis versicolor * M. furfur is a lipophilic yeast and normal skin flora * May cause systemic infections in patients receiving prolonged infusions of lipids through central catheters * Direct examination of skin scraping in 10% KOH prep Round to oval cells in clusters, accompanied by short, angular hyphae (spaghetti and meatball) * Isolation and Culture M. furfur grows poorly on regular * SAB * Produce pinpoint colonies at first * Grows well when overlaid with olive * oil (lipophilic)

Answer 6

* Superficial infection of the skin * Primarily found in tropical regions of Central and * South America and the Caribbean, and occasionally in humid regions of the US * Causes dark brown/black patches on skin of palms and sometimes the soles of the feet * Direct Microscopic Exam of Hortaea werneckii * Skin scraping in 10% KOH and Parker ink or calcoflour white mounts * Isolation and Culture of Hortaea werneckii * Colonies are slow growing (3 weeks), shiny, olive to greenish black yeast-like colonies * Two-celled cylindrical yeast-like cells that after 7 days colonies may develop a dark * septate hyphae with annellation.

Answer 7

* Formation of hard black nodules on the * shafts of the scalp, beard, mustache and groin * Primarily in tropics – Central & South * America, SE Asia & Africa * Direct Microscopic Exam * Hairs containing one or more black nodules are placed in 10-25% KOH, shows compact * masses of dark, septate hyphae and round to oval asci containing ascospores * Isolation and Culture * Hair fragments implanted onto primary * isolation media (SAB Dex agar) * Colonies of Piedraia hortae are dark greenish, * brown to black, glabrous or covered with very short aerial hyphae * Closely septate hyphae, dark and thick walled, intercalary cells

Answer 8

* White Piedra * Fungal infection of hair shaft characterized by the presence of soft white, yellowish, beige or green nodules on hair shafts of face, axilla or genital area * More common in South America, Africa and Asia * Trichosporon ovoides- scalp hair white piedra * Trichosporon inkin - most cases of pubic white piedra * Characterized by irregular, soft, white to light brown nodules * Direct Microscopic Exam * Hair should be examined using 10% or 25% * KOH or calcoflour white * Look for irregular, soft, white or light brown * nodules firmly adhering to the hairs * Isolation and Culture * Grows on SGA with antibiotics without cycloheximide, since this drug is inhibitory to some of the species * Grows rapidly, white or yellowish to deep cream colored, smooth, wrinkled, velvety with a mycelial fringe * Microscopic: True hyphae and pseudohyphae * with blastoconidia singly or in short chains

Answer 9

* Cutaneous infection from introduction of pathogen from trauma often in the feet or hands * Sulfur granules from draining sinuses * inflammation and black tissue * India from farm workers

Answer 10

* Scedosporium Complex * annelloconidia * "Lolipop" like appearance * single stalk with conidia at the tip or base * Psuedaellescheria boydii * Cat-Fur like colony * Cleistothecia

Answer 11

* Pneumonia with cysts * Pneumatocysts * Cannot be cultured * Diagnosis of cysts

Answer 12

* chronic granulomatous and suppurative disease having a primary pulmonary stage * frequently followed by dissemination to other body sites chiefly, the bone and skin * Synonymns * Gilchrist’s Disease * Chicago Disease * North American Blastomycosis * Blastomyces dermatitidis * Endemic Worldwide * Most cases are seen in North America-North American Blastomycosis. * Not Cali * Not subclinical- Not opportunistic * Manifestations * Primary pulmonary (--\> acute pulm.) * Chronic cutaneous * Extrapulmonary * Systemic * Dimorphic

Answer 13

* one-celled, smooth-walled conidia borne on short lateral to terminal hyphal branches * Diagnosis * Direct Exam * See characteristic yeast form in tissues * Fungal culture * recovery of dimorphic fungus Blastomyces dermatitidis * Exoantigen test * DNA probe * Cycloheximide in selective fungal media inhibits the yeast form of Blastomyces dermatitidis * Definitive ID * Conversion from mold phase to the yeast phase * subculture mold form to a blood agar plate and incubate at 37 C --look for characteristic yeast forms (2-4 weeks !!!)

Answer 14

* Valley Fever or cocci * Infection resulting from a soil-dwelling fungus (Coccidioides spp.) * C. immitis, C. posadasii * Disturbed arthroconidia become airborne and inhaled * Infects lungs * Incubation period: 1-3 weeks * Not transmitted from person-to-person * Epicenter: San Joaquin valley * Fungus grows in soil in summer and is dispersed in air in late summer and fall * Southwestern U.S. * Sample Types * Sputum (early morning) * Tissue Specimens (skin, lung biopsy, bone) * Body Fluids (blood, urine) * Conidia are highly infectious * Slants are preferred to plates * Inhaled arthroconidia germinate, produce sporangia * “Spherules”, divide internally into “endospores” * Acute Pulmonary * Malaise * Cough * Chest pain * Fever * Arthralgia * Weight loss * Night sweats * Anorexia

Answer 15

* Dimorphic * Causing systemic mycoses * Possess two phases * 25° C * Filamentous * 37° C * Budding yeast form or spherules * Direct microscopy * Wet preparation of fresh clinical specimens * Preparations of fixed specimens * Isolation and characterization * Primary isolation * Growth is moderately rapid * Texture is wooly to glabrous * Surface Color is white but can be beige, pink, yellow or brown * Reverse color is pale to dark brown * Hyaline, septate hyphae * Conidiophores are absent * Arthroconidia are barrel shaped alternating with empty cells called disjunctors * In infected tissue, spherules containing endospores 10-80um * Microscopic morphology: * Barrel-shaped arthroconidia * Exoantigen test: * “F” antigen, “HS” antigen * Nucleic Acid probe: * Ribosomal RNA:DNA hybrid * “Accuprobe”, Gen-probe * Direct Smear * Sputum, CSF sediment * KOH + Calcofluor – spherules w/endospores * Biopsy, stain with H&E, PAS, GMS * Rapid growth at 25C on Sabouraud medium * SCC (Sab + cycloheximide + chloramphenicol) * Buff, fluffy, yellow, tan * Many airborne arthroconidia. * At 25° C and 37° C Growth * Moderately rapid * Texture * Woolly to glabrous * Color * Surface * White, beige, pink, cinnamon, yellow or brown * Reverse * Pale, orange, or pale to dark brown

Answer 16

* Histoplasmosis is an infectious disease caused by inhalation of spores produced by Histoplasma capsulatum * Endemic areas * Central and eastern United States, around the Ohio and Mississippi River Valleys, as well as parts of Central and South America, Africa, Asia, and Australia. * Infectious particles- * microconidia, inhaled in dusts of contaminated soil. * Converts to yeast form in lungs * Influenza-like: fever, cough, headache, myalgias • Acute or chronic pneumonia • Extrapulmonary dissemination in immunosuppressed patients ( I.e. AIDS) * *

Answer 17

* Microscopic morphology: * “ tuberculate” macroconidia * Exoantigen test: * “h” antigen, “m” antigen * Nucleic Acid probe: * Ribosomal RNA:DNA hybrid “Accuprobe”, Gen-probe * Culture: can be performed on tissue, blood, and other body fluids, but may take up to 6 weeks to become positive; most useful in the diagnosis of the severe forms of histoplasmosis. A commercially available DNA probe (AccuProbe, GenProbe Inc.) can be used to confirm. * Microscopy: for detection of budding yeast in tissue or body fluids, low sensitivity, but can provide a quick proven diagnosis if positive. * Direct Smear * Sputum * Wright’s stain, Gomori metheamine silver (GMS) * Biopsy, stained with H&E, PAS, * Culture * Slow growth at 25C on Sabouraud medium * –SCC (Sab + cycloheximide + chloramphenicol) * Buff, fluffy, yellow, tan * Tuburculate Macroconidia

Answer 18

* Causative agent = Sporothrix schenckii * characterized by nodular lesions of the cutaneous or subcutaneous tissues and adjacent lymphatics that suppurate, ulcerate and drain * Gardeners’ disease --infection often occurs after thorn prick while gardening * The organism is ubiquitous in soil * The infection often follows a traumatic injury in which the wound is highly contaminated with soil * Pulmonary– inhaling the infectious conidia found in soil * Lymphocutaneous (most common) * Mucocutaneous (rare) following dissemination * Extracutaneous and Disseminated (rare) * bone, joint, eye, sinuses, CNS, systemic (multi-organ involvement)

Answer 19

* Thermally dimorphic fungus * Mold form (at 25 C) * Macroscopic --light colored (“dirty white”), moist, glaborous and yeast-like at first becoming fuzzier and darker (dark gray-brown mycelium) * Microscopic * Hyaline septate hyphae with rosettes and birds-on-a-wire conida * Yeast form (at 37 C) characteristic “cigar-shaped” yeasts

Answer 20

* Paracoccidiodes brasiliensis * Paracoccidioidomycosis is a chronic granulomatous disease that begins as an inapparant pulmonary disease which disseminates to mucocutaneous or mucosal sites * Endemic to humid, mountain forests of South America -- “South American Blastomycosis” * Associated with soil in “coffee-growing regions” (Not endemic to rain forest regions) * Primary pulmonary -- often subclinical * Progressive pulmonary -- TB-like * Disseminated disease * – mucocutaneous (most common) * – extracutaneous w/ single organ involvement * (rare) (adrenal gland most common -- Addisons disease) * Generalized disease (rare) -- many organs involved * Mucocutaneous (mostcommon) * Results from dissemination from the primary pulmonary infection * granulmonatous disease of buccal, nasal and less commonly GI mucosa * Regional lymph nodes are often involved and may form sinus tracts to the skinsurface

Answer 21

* Thermally dimorphic fungus * Direct Exam * Fungal Culture * Direct Exam of clinical material * Sputum * Biopsy material * lymph node drainage * Look for characteristic yeast having multiple buds resembling a “mariners wheel” * use selective fungal media with * chloramphenicol and cycloheximide * P. brasiliensis grows very slowly * (15 - 25 days @ 25 oC)

Answer 22

* traumatic implantation of dark fungi into subcutaneous tissue * SUPERFICIAL INFECTIONS: * Exophiala spp., Phialophora spp. * SYSTEMIC: brain abscess, severe disseminated infection * Pulmonary: lung mass * Cladophialophora bantiana (brain) * Cladosporium * Exophiala dermatitidis * Exophiala jeanselmei * Exophiala spinifera * \*Phialophora verrucosa * Exserohilum spp. * Rhinocladiella\* mackenziei * \*Fonsacaea * Alternaria alternata * Bipolaris australiensis * Curvularia lunata * Chaetomium, Phoma

Answer 23

* Black colonies * Brown hyphae and spores * Numerous species * Difficult to identify * All have one of four types of sporulation * Rhinocladiella-like * Cladosporium-like * Phialophora-like * Acrotheca-like

Answer 24

* Major cause of cerebral phaeohyphomycosis all over the world * Thermotolerant - Grows well at 42-45°C * Produces long, branching acropetal chains of blastic conidia with truncate and pointed ends * Connecting dark hila between cells inconspicuous * Cactus Like Conidia

Answer 25

* etiologic agent of eumycetoma, phaeohyphomycosis, and rarely chromoblastomycosis * Early growth mucoid, yeast-like (anamorph: Phaeoannellomyces) * Becoming velvety, olive-grey to black, producing annellated conidiogenous cells (anamorph: Exophiala)

Answer 26

* old name Wangiella dermatitidis * agent of cutaneous, deep-seated infection * may be found as a colonizer in the lungs of cystic fibrosis patients * MACRO: Black, moist, shiny, yeast-like. * 2-3 weeks, olive-grey & velvety * Microscopic: * Abundant, budding yeast-like cells; few brown septate hyphae with ellipsoidal conidia accumulating in groups * Apical phialides without a collarette produced from hyphae or on short branches; annellated pores or pegs on the sides of hyphae

Answer 27

* mucoid to glabrous, white to black colony * Yeast-like conidia (generally non-pigmented) arising in groups laterally from submerged hyphae * Older hyphal cells become dark melanoid * Rare cause of infection in immunocompromised host

Answer 28

* agent of cutaneous, deep-seated infection * Muriform conidia in simple or branching acropetal (youngest at tip) chains

Answer 29

* Species of Bipolaris are agents of sinusitis and rarely deep-seated infections * Holoblastic conidia, darkly pigmented, distoseptate (not partitioned side-to-side by septa), with non-protruding hila borne on geniculate (bent-knee) conidiophores

Answer 30

* Cause of subcutaneous infections, sinusitis, and keratitis * Large, brown-pigmented, thick-walled, multi-celled conidia with disto-septa produced on geniculate conidiophores * ASSOCIATED WITH COMPOUNDED PHARMACEUTICAL [STEROID] PRODUCTS CONTAMINATED WITH DUST/DIRT * USED FOR INFECTIONS INTO LUMBAR SPINE AND KNEE JOINTS FOR PAIN MANAGEMENT * MENINGITIS SPINAL ABSCESS * SYNOVIAL INFECTIONS

Answer 31

* Major etiologic agent of keratitis, sinusitis, and deep infection especially in immuno-compromised patients * Holoblastic conidia curved, occasionally straight, several-celled, smooth or verrucose, with protuberant hilum produced on geniculate conidiogenous cells

Answer 32

MACRO: cream-colored and velvety becomes grayish beige to olive-brown. clusters or aerial hyphae. Reverse is tan to brown MICRO: Phialides along hyphae or on branched or unbranched conidiophores. Slightly tapering towards the apex. Basal septum and a collarette that is small and tubular or vaguely funnel shaped. Conidia are hyaline, oblong, some curved – gathered in clusters at end of phialide

Answer 33

* Respiratory sites * Can cause nail and skin infection * Severe cases – nervous system * Can produce toxins * Dematiceous * Velvety texture (5 days growth), sandy in color; reverse tan or darker brown/black * Microscopic: brown, septate hyphae, large fruiting body – perithecium, which develops to ostiole, release ascospores

Answer 34

* For subcutaneous nodules, surgery * Itraconazole - excellent and used the most * voriconazole and posaconazole * Duration of therapy: 6 wk to \> 12 months * Amphotericin B is often ineffective * For brain abscess, include surgical resection if possible. * For brain abscess or disseminated infections, combination therapy (eg, with 2 or 3 drugs, at least one of which is an azole)

Mycology Flashcards

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