M1. Systemic Mycoses Flashcards
particularly “Primary” Systemic Mycoses– to differentiate it from other pathogenic fungal elements because some species can also cause disseminated systemic infections
ENDEMIC MYCOSES
what are the primary systemic mycoses
● Coccidioidomycosis
● Histoplasmosis
● Blastomycosis
● Paracoccidioidomycosis
● On Sabouraud Dextrose Agar at 25 - 30 deg C
● Saprophytic, observed in vitro
MYCELIAL PHASE
● OnEnriched media w/ Blood, 35– 37 deg C
● Seen in vivo, aka “tissue/invasive phase”
YEAST PHASE
MOT of systemic mycoses
● Inhalation of Fungal Spores (Most common)
● Dissemination
● Geographic Restrictions
serological tests for systemic mycoses
Complement Fixation Test
Immunodiffusion Test
Tube precipitin Test
Enzyme Immunoassay
The initial host defenses are provided by the __________,
which are usually capable of inactivating the conidia and inducing a robust immune response
alveolar macrophages
coccidioidomycosis is aka
o Valleyfever
o SanJoaquinValley Fever
o Desert fever/ desert rheumatism
mot of coccidioidomycosis
inhalation of arthroconidia
valley fever is disseminated in what organs
visceral organs
meninges
skin
bone
lymph nodes
subcutaneous tissues
coccidioidomycosis occurs more frequently in certain racial groups (commonly on dark-skinned individual); in decreasing order:
filipinos
african americans
native americans
hispanics
asians
The new environment (37 deg C) signals a morphologic
change, and the arthroconidia become
SPHERULES
california spp
Coccidioides immitis
“Non-California” spp.
▪ CommoninMexico
▪ Slow growing on media with high salt
concentration (Halophilic)
Coccidioides posadasii
Coccidioides immitis– LABORATORY DIAGNOSIS
- blood testing, pcr, chest x-ray
- direct examination (10-20% KOH; calcoflour white)
Thick-walled barrel-shaped, rectangular arthroconidia that alternate with empty cells called
disjunctor cells
Coccidioides immitis in yeast/tissue form
components of outer wall
Mannan, protein, lipid
Coccidioides immitis in yeast/tissue form
components of inner wall
Chitin, 3-O-Methyl mannose
- agars used in c. immitis
- texture and color
- sabouraud dextrose agar and inhibitory mold agar
- delicate, fluffy white, which turns tan or brown with age
● The MOST INFECTIOUS of all fungi
● Formerly a “Select agent”– biological agent that has the potential to pose a severe threat to public health and safety
Coccidioides immitis
Skin Tests for Coccidioidomycosis
- Coccidioidin
- Spherulin
Confirmatory Tests for Coccidioidomycosis
IMMUNODIFFUSION TEST
positive rxn of coccidioidomycosis in immunodiffusion test
Precipitin line/band formation
treatment for severe cases of coccidioidomycosis
posaconazole or amphotericin b
Serological Test for Coccidioidomycosis and what is the sample used
COMPLEMENTFIXATION TEST; px serumq
treatment for moderate cases of coccidioidomycosis
fluconazole and itraconazole
● Most prevalent pulmonary mycosis
● Chronicgranulomatous infection
● Beginsinthe lungs with Tuberculosis-like infections
o ResemblesS/sof TB
● Mostlyasymptomatic and self-limited
● Maydisseminate and Re-infection may occur
Histoplasmosis
mot of histoplasmosis
Inhalation of conidia or small hyphal fragment
Sources of Infection: Histoplamosis
● Silos, air-conditioning units contaminated with BIRD
DROPPINGS
● Accumulations of guano (debris of bats) in caves, attics, or parks
● Nitrogen-rich soils
Clinical Manifestations of Histoplasmosis
ACUTE PULOMARYHISTOPLASMOSIS
CHRONIC PULMONARYHISTOPLASMOSIS
DISSEMINATED HISTOPLASMOSIS
OCULARHISTOPLASMOSIS
LaboratoryDiagnosisofHistoplasmacapsulatum
Culture:
LYSIS CENTRIFUGATION METHOD
- agars used in c. immitis
- texture and color
- Sabouraud Dextrose Agar/ Inhibitory Mold Agar(mold)/ BrainHeart InfusionAgar (YEAST)
- White→brown, finefluffy;white,yellow,or tanon
reverseside
● Produced by growing themycelium in asparagine broth medium
● PositiveReaction: indicated by an area oF induration>5mmin diameter after 48hours
Histoplasmin Skin TesT
Serology Tests for Histoplasma Capsulatum
○ Complement FixationTest
○ ImmunodiffusionTest
○ Direct Fluorescent Antibody Test
○ Counterimmunoelectrophoresis Test
Treatment for Histoplasma Capsulatum
1. Acute Pulmonary Histoplasmosis Management
2. Treatment for Mild to Moderate Infection
3. Disseminated Disease Treatment
4. AIDS Patients Treatment Approach
- Supportive therapy and rest
- Itraconazole
- AmphotericinB
- Maintenance therapy with itraconazole0
● Chronicsuppurative and granulomatous infection
○ Withpusandgranules
○ CommonwithDogsandCats(Zoonotic)
Blastomycosis
SEROLOGY TESTS OF BLASTOMYCOSIS
Complement Fixation
Immunodiffusion
Enzyme Immunoassay Test
causative of blastomycosis
blastomycoses dermatitidis
Clinical Manifestations of Blastomycosis
PRIMARY CUTANEOUS BLASTOMYCOSIS
CHRONIC CUTANEOUS BLASTOMYCOSIS
DISSEMINATED BLASTOMYCOSIS
PULMONARY BLASTOMYCOSIS
Most common from of blastomycosis clinical manifestation
PULMONARY BLASTOMYCOSIS
Treatment for Blastomyces dermatitidis
Itraconazole (Oral)
Amphotericin B (Intravenous)
● Chronicgranulomatous infection
● Beginsasaprimary pulmonary infection
● Asymptomatic but may disseminate
● Infects: Nasal or oral cavity, gingiva, and conjunctiva
● Donotspreadfromperson-to-person
Paracoccidioidomycosis
Clinical Manifestations of Paracoccidioidomycosis
● AsymptomaticForm(Most of the time)
○ Initial form
○ Latent
● SymptomaticForm
○ Juvenile type
■ swollenlymph node and skin lesions
○ Adult type (Pulmonary & Disseminated)
MOT of Paracoccidioidomycosis
Inhalation of fungal structures
Serologic Tests for Paracoccidioides brasiliensis infxn
Immunodiffusion Test (most useful)
Complement Fixation Test (useful for assessing prognosis)
