Clinical Micro- Mycology

Candidiasis: C. albicans is apart of what three normal flora? Most types of infections are? cause Mucosal infection known as?

1. GI tract (most common) 2. Skin 3. Vagina ENDOGENOUS- duh "thrush" - Present as cottage cheese like patches on mucosal surfaces of oropharynx

Aspergillosis: Caused by what 4 species? Immunocompetent patients present with? Immunocompromised? creates? Marked by?

A. fumigatus, A. flavus, A. niger, A. terreus -allergic reactions - invasive pulmonary disease with dissemination "fungus ball" in the lower airway formation of bronchial casts/plugs composed of hyphal elements & mucinous material

Aflatoxins: produced by? Found in? Causes?

Aspergillus sp. cereal grains and peanuts acute and chronic hepatitis (which can lead to hepatic cancer)

Blastomycosis: Caused by? Endemic where? Infection acquired after? Pulmonary symptoms? Systemic- classically involves? this is due to?

Blastomyces dermatitidis confined mostly to Ohio & Mississippi River Basins in US and southeast states inhalation of aerosolized conidia growing in soil and leaves severe infections resemble bacterial pneumonia with possible progression to adult respiratory distress syndrome skin due to hematogenous spread from lungs -Can also involve prostate, liver, spleen, kidney, CNS

what is the agar needed for most isolates? Rapid ID of Candida sp. accomplished by use of? Gram stains: Yeasts will stain? Hyphae will stain? Giemsa stain Routine clinical stain to examine? 2 detects? 2

Brain heart infusion (BHI) chromogenic agar gram positive gram negative bone marrow & peripheral blood Histoplasma and Pneumocystis jirovecii

Standard culture bottles useful for identifying sepsis, or fungemia, cause by? specialized bottles are useful for identifying? 2 Respiratory tract culture can be used for? 4

Candida sp. Cryptococcus neoformans Aspergillus sp. primary pathogens (dimorphic fungi) Cryptococcus neoformans Aspergillus Mucor/Rhizopus

Sporotrichiosis: looks like? Characterized by?

Classic "rose-pruning" disease nodular & ulcerative lesions develop along lymphatics that drain site of primary infection

Main purpose of fungi? All fungi lead a what existence? organisms that live on dead or decaying matter are? organisms that live together & whose association is of mutual advantage are? organisms living in a close relationship where one benefits and the other is not benefited, nor harmed?

Degrade organic matter heterotropic existence Saprobes Symbionts Commensals

Calcofluor white: is? requires? Fluorescent antibody stain: is? PAS (periodic acid-schiff): stains for? Mucicarmine: deomstrates?

Fluorescent stain that detects chitin in fungal cell wall fluorescent microscope Most sensitive and specific method for ID of Pneumocystis jirovecii both yeast and mold elements in tissue • However, PAS-positive artifacts can resemble yeast cells the capsule of Cryptococcus neoformans

Fumonisins: produced by? Found in? Causes?

Fusarium moniliforme corn dysphagia and can lead to esophageal cancer

Opportunistic pathogens are all? however.......3 EXCEPTIONS? 3

MOLDS 1. Candida sp. - yeast that colonizes humans & produces endogenous infections 2. Cryptococcus neoformans - exists as a yeast in nature & acquired through the INHALATION of YEAST CELLS (not spores) 3. Pneumocystis jiroveci - yeastlike fungus that colonizes humans, but produces disease in immunocompromised

Mold: is? Fundamentally, molds consist of? 2

Multicellular organisms composed of branching filaments (hyphae) that grow by apical extension (elongation of tips) forming myceilum filaments (hyphae) with budding forms (spores)

Pneumocystosis (PCP): Caused by? Occurs exclusively in? what is most common presentation? Hallmark infection is? what is seen in alveolar spaces? Dx entirely based on?

Pneumocystis jirovecii severely immunosuppressed individuals Pneumonia interstitial pneumonitis with mononuclear cell infiltrate composed of plasma cells Foamy exudate microscopic exam of clinical material

Mucormycosis: Rare disease of what two molds? Infection acquired by? Two presentations?

Rhizopus and Mucor inhalation, ingestion or contamination of wounds with sporangiospores 1. Rhinocerebral mucormycosis - • Invasive infection of nasal cavity and sinus with extension to CNS. 2. Pulmonary mucormycosis - • Invasive pulmonary infection, with predilection to invade large caliber vessels prompting thrombosis. • Dissemination results in infection of solid organs with accompanying infarcts

Coccidioidomycosis: Primary disease that doesn't resolve can progress to? Dissemination occurs when? to? what Groups are at Higher Risk for Disseminated Disease?

Secondary disease -nodules -cavity formation in lungs -pulmonary disease 1% of infected individuals - skin, soft tissue, bones, joints, meninges • 9:1 male to female • pregnant females • Immunocompromised

Histoplasmosis: causes disease marked by? after some heavy inoculation exposures what can occur?

Self limiting acute disease is marked by flu like symptoms (fever, chills, myalgia, cough) ARDS

Lymphocutaneous Sporotrichiosis: caused by? at room temp it is? at body heat? lives where?

Sporothrix schenckii • Room temp= mold • Body heat yeast → elongated cells called "cigar bodies" soil and dead/decaying vegetation

Coccidioidomycosis: diagnosis from what form? Treatment?

Yeast - spherules (20-60 μm) containing endospores - Mold - barrel shaped conidia • Most patients do NOT require specific antifungal therapy

B. dermatitidis: diagnosis is made from what form? this is presented at what temp? it presents as? Diagnosis is made from what sample?

Yeast @ 37°C • DISTINCT & Diagnostic! - Spherical, hyaline, multinucleated yeast cells with thick "double-contoured" walls with broad-based budding • Sputum, BAL, lung biopsy, skin bx, CSF

Paracoccidioidomycosis: Diagnostic morphology seen in what form? what appearance? mold phase shows?

Yeast Phase "Mariners-wheel" or "Pilot-wheel" appearance: • Oval • double refractile walls & multiple buds ("pilot-wheel") septate hyphae with thick-walled spores

Primary Fungi Pathogens: are? 3 characteristics? 3 Common Dissemination Sites? 4 ex?

are sufficiently virulent to infect a healthy, immunocompetent host • Dimorphic • Acquired through inhalation • Cause systemic disease • CNS • Skin • Bone Marrow • Blastomyces • Histoplasma • Coccidioides • Paracoccidioides

Dimorphic fungi will grow how?

as a mold with hyphal elements at room temperature and will grow like a yeast at body temperature

Sporangiospores is? Conidia is?

asexual reproductive elements produced in a sporangium (enclosed structure) specialized structure that functions as asexual reproductive elements that are easily airborne & disseminate the organism -develop as chains along the hyphae's extending apical tips

Aspergillosis: diagnoses by? is treated how? H&E - notes?

culture of MOLD with caution as Aspergillus can be a contaminant acutely branched septated hyphae -cute little puff balls on the end

Superficial mycoses involve? Diagnosis is made by?

cutaneous aspect of the body: dead layers of skin, nails, hair microscopically examining scrapings or clipping

Onychomycosis: usually caused by? other? When nail clippings are sent to surgical pathology, order?

dermatophytes Non-dermatophytes • Candida, others (Scopulariopsis, Aspergillus, Fusarium) PAS stain

Cocciodioidomycosis: endemic where? Seen in environments with? what initiates the infection? clinical course?

desert southwest of US • Especially southern CA bat / rodent droppings inhalation of conidia-the most virulent fungal infection • Self-limiting flulike disease • 60% of infected individuals are asymptomatic

Mucormycosis: Diagnosis depends on? Typical specimens are? H&E shows? PAS shows?

direct microscopic exam or histopathology, not on culture alone nasal mucosa, sinus contents (aspirate), biopsy, I&D necrotic tissue, sometimes lung broad, irregularly branched, twisted hyphae broadly branched nonsepta (coenocytic) hyphae

Cryptococcosis: Systemic mycosis caused by? what type of organism? found where? Acquired by? Starts with pulmonary focus then causes? Diagnosis usually made by?

encapsulated yeast-like fungus Cryptococcus neoformans Saprophitic organism found ubiquitous in soil, especially that which has been enriched with pigeon droppings inhaling aerosolized cells from the environment hematogenous spread to CNS-Most common cause of fungal meningitis latex agglutination or enzyme immunoassay

Penicilliosis: Microscopic detection of what form? culture shows? Confirm with culture at what temp? yeast looks like?

mold form - at 25°C characteristic RED colonies, diffuses into agar 37°C - at the yeast form • Elliptical fission yeast cells inside phagocytes (intracellular) • Transverse septae • Found in buffy coat preps, bone marrow smears, or LN touch preps

Special stains (GMS and PAS) should always be ordered up front on a biopsy if clinical suspicion is? Rapid fungal antigen detection (EIA) is widely used for?

mucormycosis. - It is often a STAT case identification of Cryptococcus neoformans

Candidiasis: most important group of? Third most common cause of? what 4 species cause disease?

opportunistic fungal pathogens bloodstream infections (BSIs) associated with central lines • Candida albicans (most common), C. glabrata, C. parapsilosis, C. tropicalis.

Histoplasmosis: Progressive Pulmonary infection occurs in what patients? symptoms? Disseminated histoplasmosis: occurs in? 1. Chronic disseminated disease presents with? 2. Subacute disseminated disease is marked by? 3 Involved Anatomic Sites? 3. Acute disseminated histoplasmosis: presents as?

patients with underlying lung issues • Apical cavities & fibrosis withOUT spontaneous healing • 1 in 2000 adults, higher rate in children and immunocompromised • Weight loss & fatigue, with or without fever • Oral ulcers • Hepatosplenomegaly fever, weight loss & malaise • Bone Marrow → anemia, leukopenia, thrombocytopenia • CNS • Heart valves Similar to septic shock death in days if untreated

Mycotoxins: are?

secondary fungal metabolites (toxins) produced by molds that have adverse effects on humans, animals and crops - causing disease & death -also can make antibiotics :)

Citreoviridin: produced by? Found in? Causes?

several Penicillium sp. rice (Japan) cardiac beriberi: palpitations, vomiting, and respiratory failure

Special properties: Fungi are distinguished based on? fungi have a cell membrane in which? Classic fungal taxonomy relies heavily on? Most fungi are?

their rigid cell wall composed of chitin and glucan ergosterol is substituted for cholesterol morphology & mode of spore production dimorphic - yeast and mold

Yeast: are? A cell that is reproduced by? Daughter cells may be elongated to form?

unicellular form "budding" or "fission", where a "mother cell" pinches off a portion to produce a "daughter cell" sausage-like pseudohyphae

Candidiasis: what can occur following GI surgery? Candida CNS infections secondary to? what is diagnostic microscopically?

• Candida peritonitis hematogenous spread, brain surgery or shunt placement biopsy- H&E, PAS, GMS - Budding yeast cells & pseudohyphae

Derrmatophytoses: these fungi are? 2 Most infections caused by what molds? 3

• Keratinophilic - affinity to keratin (ie LOVES it!) • Keratinolytic - causes lysis of keratin • Trychophyton • Epidermophyton • Microsporum

Penicilliosis (Talaromycosis): caused by? Disseminated involves? Occurs in what individuals? Critical risk factor? Symptoms?

• Penicillium (Talaromyces) marneffei - dimorphic fungus the mononuclear phagocytic system HIV-infected individuals of Thailand & southern China exposure to soil/decaying material in humid conditions • Inhalation of conidia from environment - Fever, cough, lung infiltrates - Lymphadenopathy, organomegaly - Anemia, leukopenia & thrombocytopenia

Paracoccidioidomycosis: is? Major dimorphic fungus endemic to? Natural reservoir is? 2 forms?

• Pulmonary / Systemic mycoses Latin American countries armadillos 1. Pulmonary Form (acute or chronic) 2. Disseminated form • Rare •common sites include → skin, mucosa, LN, spleen, bone, CNS • 9:1 male to female ratio

Histoplasmosis: is? Endemic Areas? seen in? what induces infection? Infection Route?

• Pulmonary / Systemic mycoses • Eastern US / Latin America - pulmonary & disseminated infection • Africa (tropical areas) - skin & bone lesions soil with high nitrogen content (bird & bat droppings) Inhalation of aerosolized microconidia & hyphal fragments • Microconidia phagocytosed by pulmonary macrophages & neutrophils • Intracellular conversion into yeast cells • Yeast cells may remain in lung or disseminated via blood / lymphatics

Mold: Characteristics of hyphae? 2 Hyphae form what on agar? these produce? 2

• Septate hyphae • Coenocytic (non-septate) hyphae mycelium on agar - (filamentous/wooly, mat-like structure) - vegetative hyphae (grows below agar surface) - aerial hyphae (projects above agar surface)

Histoplasmosis: mold phase presents as? Yeast phase presents as? which one is diagnostic?

• Thick-walled, spiked macroconidia "tuberculate macroconidia" • mixed with small oval microconidia (top 1) • Intracellular structures in macrophage • Thin-walled, hyaline, oval • Uninucleate • Narrow-based budding (bottom 2) yeast

Dermatophytoses: Tinea capitus? Tinea corporus? Tinea cruris? Tinea pedis? Tinea unguium?

• Tinea capitus - head • Tinea corporus ("ringworm") - body, glabrous skin • Tinea cruris - groin • Tinea pedis ("athlete's foot") - feet • Tinea unguium - nail (aka "onychomycosis")