Fungi Infections Pt 2

Yeast, lung, 5, 2, respiratory, cholesterol, cyst, HIV/AIDS

Pneumocystis jirovecii

• Opportunistic __

• Distribution - Global human __  flora; most people exposed before age _

• _ (#) forms/stages in lung

• Transmission - __, person-to-person

• Virulence factors - __ cell wall, reproduce in __ form

• At Risk: Immunocompromised, individuals with __/__, transplantation

Trophozoite

Asexual reproducing pneumocystis in lung

Cyst

Sexual conjugation of haploids with several intracystic bodies (pneumocystis)

Round, helmet, ping pong, sporozoite

Pneumocystis jirovecii Cyst Form

• Physical Traits of cyst type - __, __, dented __ __ ball

• Release __ → Becomes a Trophozoite form

Pneumonia, outside, infiltrates

Pneumocystis jirovecii Disease

• __ in immunocompromised individuals

• Rarely spreads __ lungs

• Presentation - Bilateral lung __ on exam, dyspnea, fever, cough

sputum, biopsy, PCR, ground glass, prophylactic

Pneumocystis jirovecii Dx + Tx

• Identified in __ sample/BAL/lung __

• __ for pathogen specific antigens

• Chest X-ray: Note bilateral “__ __” opacities

• Tx - variable mortality, no vaccine, __ antifungals for immunocomp

Di, systemic, hyphae, spores, yeast

Histoplasma capsulatum Traits

• __morphic and __ fungi

• Thermally dimorphic

  • Environment - __ with microconida __

  • Human Body Tissues - Budding __

Central, eastern, feces, spores, soil, AIDS, macrophage

Histoplasma capsulatum

• Distribution - Most prevalent mycosis in US including __ and __ North America

  • Associated with bat and bird __ (soil rich with Nitrogen)

• Transmission - Inhalation of __ from the environment (__)

• At Risk- Immunosuppressed, HIV/__, lymphoma

• Virulence factors - Replication within __ cells

Soil, feces, yeast, macrophages, phagolysosome, dissiminate, adaptive

Pathogenesis of Histoplasma capsulatum

• Inhalation of spores from the __ with bird/bat __

• Body temperature causes transition of fungi to __ form

• Yeasts phagocytosed by __ → Prevent __ acidification and fusion

• Infected macrophages transport yeasts thru body and __ infection

• Infection clearance needs __ immunity

Pulmonary Histoplasmosis

Sx - Cough, fever, chills, chest pain, arthritis, headache, granuloma formation, lung cavitation

• From Histoplasma capsulatum infection

Disseminated Histoplasmosis

Sx - Macrophage spread to blood, lymph, spleen, skin, GI, liver

• From Histoplasma capsulatum infection

Primary Cutaneous

Sx - Umbilicated papule, nodule, ulcers, rare outcome

• From Histoplasma capsulatum infection

Mediastinal, hilar lymphadenopathy, M, G, community-acquired pneumonia, self-limiting

Histoplasma capsulatum Dx + Tx

• Chest X-ray: Focal infiltrates and __ or __ __

• also PCR, biopsy staining

• Serology (Ig_, Ig_) appears after 4 weeks

• Often mis-diagnosed for __-__ __

• Tx - Lung infection is often __-__

Di, systemic, hyphae, endospores

Coccidioides immitis and posadasii Traits

• __morphic and __ fungi

• Thermally dimorphic

  • Environment - Branching __

  • Human Body Tissues - Spherule-filled with __

Arizona, rodents, spores, soil, African, spherules, azol

Coccidioides immitis and posadasii

• Distribution: Arid (desert) regions of Americas → __

  • Associated with __ (animal)

• Transmission - Inhalation of __ from the __

• At risk - __ descent, immunosuppressed, soil exposure

• Virulence factors - Reproduce inside __ → “endosporulation”

  • High __ resistance to tx

Valley fever

Sx - Flu-like illness with fatigue, cough, fever, night sweats, rash

• From Coccidioides immitis and posadasii infection

Invasive coccidioidomycosis

Sx -  Endosporulation spreading to other tissues in rare cases

• From Coccidioides immitis and posadasii infection

Serological, bacterial pneumonia, soil, azol

Coccidioides immitis and posadasii Dx + Tx

• Dx - __ test for exposure (IgM, IgG), also PCR

  • Often infection misdiagnosed as __ __

• Tx - Low preventability due to __ distribution

  • No vaccine, antifungals have high levels of __ resistance

Superficial, mold, soil, fomites, showers, sports, clothing, keratin

Dermatophytes

• __ and subcutaneous __

• Distribution - Worldwide in __ (enviro), animals, among humans

• Transmission - Direct contact with infected human or animal, or indirect from __

• At risk - Immunocompromised, public __ use, contact __, wear tight __

• Virulence factors - Produce enzymes that digest __

Tinea Versicolor

Hypo-/hyper-pigmented skin patches (dermatophytes)

Seborrheic Dermatitis

Pruritic, erythematous, scaly patches to hair (dermatophytes)

Tinea Capitis

Scaly patches, broken hair shafts to head/scalp (dermatophytes)

Tinea Corporis

Pruritic rash, scaly border, clear center to body (dermatophytes)

Tinea Cruris

Pruritic, erythematous rash, scaly border to groin (dermatophytes)

Tinea Pedis

Scaly pruritic rash between toes (dermatophytes)

Onychomycosis

Thick, discolored, deformed nails (dermatophytes)

Superficial, KOH, topical

Dermatophytes Dx + Tx

• Dx - Noting a __ cutaneous infection

  • Scraping of lesion and __ stain

• Tx - __ OTC antifungals

Pneumocystis, Histoplasma, Coccidioides, Dermatophytes

Fungi from this lecture

Opportunistic yeast - (1)

Dimorphic and systemic yeasts - (2)

Superficial-infecting mold - (1)