Systemic (Endemic) Mycoses

Question 1

@ 37C

Answer 1

mold 2 yeast

Question 2

@ 25C

Answer 2

yeast to mold

Question 3

Coccidioidomycosis

Answer 3

C. immitis (CA), C. posadasii (outside CA)Valley feverSW US

Question 4

Coccidioides spp MORPHOLOGY

Answer 4

DimorphicSPHERULE W/ENDOSPORESArthoconidium

Question 5

Coccidioides spp PHYSIOLOGY

Answer 5

Soil organismWhite, wooly colony

Question 6

Coccidioides spp SPHERULE

Answer 6

Lipid rich20-80um diameter, located inside giant cell”endosporulating spherule”Susceptible tissues: lungs, skin, cardiac, pericardium, bones, CNS

Question 7

Coccidioides immitis

Answer 7

Sabouraud agar - woolyslow-growing (1-2wk)

Question 8

Antigens for immunodx: C. immitis

Answer 8

CoccidioidinSpherulin

Question 9

C. immitis PATHOPHYSIOLOGY

Answer 9

Involves pulmonaryInhale arthroconidia– transforms into pulmonary spherules that contain endospores.Endospores released, produce new spherulesSeptate hyphae & arthroconidia sometimes present in pulmonary cavitiesPrimary disease: self-limited influenza-like illnessMay develop into diffuse pneumoniaPossibly asymptomatic

Question 10

C. immitis PATHOGENICITY (disseminated)

Answer 10

May involve lungs, skin, bones, joints, CNS (rarely)IMMItis affects IMMIgrants& preggos (elevated estradiol/progesterone enhances growth)Erythema nodosum - delayed hypersensitivity to fungal antigens (good prognosis)

Question 11

Coccidioides EPIDEMIOLOGY

Answer 11

Airborne (not communicable)Soil-dwelling: arthroconidiaMore common in older adultsIncreasing number of cases

Question 12

Coccidioides ID/DX

Answer 12

PAS exam: giant cells/spherulesCulture on Sabouraud agarincreased IgM/IgG

Question 13

Coccidioides THERAPY

Answer 13

Fluconazole Itraconazole Amphotericin BFor disseminated disease - long term treatment

Question 14

Coccidioides CONTROL

Answer 14

Dust protectionPave roadsPlant vegetaionNo vaccine

Question 15

Coccidioides CASE STUDY

Answer 15

Scaly, verrucous rash (&lesions)Involvng nose, head, torso//chronic cough/low-grade fever//persistentrecurrent rashSouthern CAnight sweats/arthralgia/back painpositive IgG/IgM antibodiesGranulomatous inflammation & fungal spherules w/in multinucleated giant cells

Question 16

Histoplasma capsulatum MORPHOLOGY

Answer 16

DimorphicUninucleate budding cells (blastoconidia)Mold features: micro & tuberculate macroconidia

Question 17

Histoplasma capsulatum PHYSIOLOGY

Answer 17

Facultative intracellular parasite (macrophages/PMNs)Culture: yeast @ 37C; mold: 25C

Question 18

Histoplasma capsulatum PATHOPHYSIOLOGY

Answer 18

Influenza-like to severe lung diseaseRETICULOENDOTHELIAL DISEASEMicroconidia are inhaledDevelop into yeast cellsCells may be phagocytosed/disseminated

Question 19

Histoplama capsulatum: HISTOHIO BATS YEAST IN ALL FIGHTS W/P’S & N’S

Answer 19

Granulomatous foci

Question 20

Histoplasma capsulatum

Answer 20

FeverPulmonary illnessWeight lossGI involvement

Question 21

H. capsulatum VFs

Answer 21

Yeast releases urease, ammonia, bicarbonateEnables yeast to raise pH & blunt or eliminate killing action of phagolysosome

Question 22

H. capsulatum - host resistance

Answer 22

PMN expresses fungistatic activity & functional T cell-mediated immunity is critical for clearance

Question 23

H. capsulatum EPIDEMIOLOGY

Answer 23

Ohio/MS River valleysNot communicableBat’s intestine

Question 24

H. capsulatum ID

Answer 24

Microscopic - intracellular yeastCulture - tuberculate macroconidiaDetection of antigen or antibody (histoplasmin)

Question 25

H. capsulatum THERAPY

Answer 25

Chronic pneumonia & disseminated disease - itraconazole /amphotericin B

Question 26

Antigen for immunodiagnosis (H. capsulatum)

Answer 26

Histoplasmin

Question 27

H. capsulatum CONTROL

Answer 27

Protection from dust

Question 28

H. capsulatum CASE STUDY

Answer 28

Marked weight loss, diarrhea, dry cough, fever, night sweats.Multiple nodular lesions found in lungVegetating ulcerous lesionYeast cells w/in macrophages

Question 29

Blastomycosis

Answer 29

Chronic granulomatous disease

Question 30

B. dermatitidis MORPHOLOGY/PHYSIOLOGY

Answer 30

Thermally dimorphicBroad - based yeast in tissue/exudateHyphae bear conidia/chlamydospores

Question 31

B. dermatitidis PATHOPHYSIOLOGY

Answer 31

Inhale infective stage (microconidium in soil)May produce acute/chronic pulmonary diseasePossibility of dissemination

Question 32

B. dermatitidis EPIDEMIOGY

Answer 32

Not communicable person to person: soil organism

Question 33

B. dermatitidis ID/DX

Answer 33

Metastatic skin lesionsBroad-based yeast (KOH, sputum/exudate/biospy)Culture on Sabouraud agar

Question 34

B. dermatitidis THERAPY

Answer 34

Disseminated disease requires aggressive therapyDOC: itraconazole / amphotericin B

Question 35

B. dermatitidis CLINICAL PERSPECTIVE

Answer 35

persistent fever/cough/yellow sputumChest radiograph: unilateral pleural effusionProfound weight loss/ulceronodular lesion on the handBroad-based budding yeast in PAS-stain reveals fungal etiology

Question 36

Paracoccidioidiomycosis

Answer 36

P. brasiliensis"mickey mouse"

Question 37

P. brasiliensis

Answer 37

Yeast w/multiple budsPossibly self-limitingConfined to central/south americaTherapy: itraconazole/amphotericin B

Question 38

P. brasiliensis CASE STUDY

Answer 38

71 y/o Chinese manchronic cough/malaise for 2 mo4-mo vaca in AZlow-grade fevernecrotic granulomatous inflammation w/multinucleated giant cells containing spherulespositive PAS