Opportunistic Mycology

Question 1

Unusual fungal organism that lacks ergosterol (used to be thought of as protozoan)

Usually in HIV pts, organ transplant pts

Answer 1

Pneumocystosis

Pnemocystis jiroveci/carinii

Question 2

Predilection for DKA patients –> thrive in gluose and keones and prefer acidic pH

Answer 2

Mucormycosis
Absidia (Mucor) corymbifera
Rhizopus arrhizus
Rhizopus oryz

Question 3

Ubiquitous fungus with > 900 species

Macro: rapidly growing , velvety texture (white–>green)

Micro: septate hyphae with 45 degree branching

Answer 3

Aspergillosis

A. fumigatus

Question 4

Increased with increasing organ transplants

Usually in cancer or organ transplant pts

Answer 4

Systemic Candidiasis
C. albicans
C. tropicalis
C. parapsilosis
C. glabrata

Question 5

Only major pathogen to be a mushroom

Four serological subtypes causing 95% of infections in US

Answer 5

Cryptococcosis
Cryptococcus neoformans

Found highly in pigeon excreta and koala excreta (can survive for years)

Question 6

Ubiquitous fungi found in decaying organic debris

Common cause of bread mold

Answer 6

Mucormycosis
Absidia (Mucor) corymbifera
Rhizopus arrhizus
Rhizopus oryz

Question 7

Primarily pulmonary: asymp, can be pneumonia like

Primary cutaneous inoculation rare

Disseminated most commonly involves CNS (meningitis)

Answer 7

Cryptococcosis

Cryptococcus neoformans

Question 8

Endocarditis (parapsilosis, guilliermondii)
UTIs
Septicemia
Commonly affects skin and eyes!
Meningitis (rare)

Answer 8

Systemic Candidiasis
C. albicans
C. tropicalis
C. parapsilosis
C. glabrata

Question 9

Pulmonary: allergic

Disseminated: immunocompromised, usu affects lungs, brain, kidneys

Cutaneous: (IV site) or disseminate for lungs; chronic variant may resemble leprosy

Answer 9

Aspergillosis

A. fumigatus

Question 10

Most acute and fulminant infection: 50% mortality

Rhinocerebral: upper turbinates or paranasal sinuses –> most commonly in DKA

Answer 10

Mucormycosis
Absidia (Mucor) corymbifera
Rhizopus arrhizus
Rhizopus oryz

Question 11

dypnea, fever, nonproductive cough, diffuse bilateral infiltrates on CXR

May disseminate to lymph nodes, spleen, liver, bone marrow, ext auditory canal

15% fatality rate

Answer 11

pcp

Question 12

 Does not culture well
 “Cap-like” appearance
 Sputum, CXR, BAL, GMS

Answer 12

Pneumocystosis

Pnemocystis jiroveci/carinii

Question 13

 Macro: white wooly
 Micro: rhizoids (root-like)
 Biopsy (broad non-septate hyphae with right angle branching)

Answer 13

Mucormycosis
Absidia (Mucor) corymbifera
Rhizopus arrhizus
Rhizopus oryz

Question 14

 Moist mucoid colonies

 India Ink (see capsule)

Answer 14

Cryptococcosis

Cryptococcus neoformans

Question 15

 Biopsy (psuedohyphae with yeast)

 Culture

Answer 15

Systemic Candidiasis
C. albicans
C. tropicalis
C. parapsilosis
C. glabrata

Question 16

 KOH

 Common contaminant of fungal cultures

Answer 16

Aspergillosis

A. fumigatus