Fungal Meningitis- Cryptococcus Flashcards by Iseoluwa Ojo

Cryptococcus

Ubiquitous (unencapsulated or encapsulated?) (yeasts or molds?) belonging to the division __________.

_______________ are inhaled from environment

The fungus (can or cannot?) spread from person to person

encapsulated; yeasts

Basidiomycota

Fungal spores

Cannot

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Cryptococcus

Over _____ species of Cryptococcus are known, however, Cryptococcus _______ and C._____ are the two main species implicated in nearly all cases of human cryptococcosis.

neoformans; gattii

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Cryptococcus

C. neoformans has 2 distinct varieties:

C. neoformans var. _________
C. neoformans var. ________

Other species of less clinical significance includes:
C. ________ , C._______, C. _______, etc.

neoformans

grubii

laurentii; adeliensis; albidus

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Cryptococcus

Yeast: ______ or ______ shaped

• _______ in diameter

•Surrounded by ___________________

•20-30mm thick

round or oval

4-6mm

polysaccharide capsules

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Cryptococcus

“_______” cells

~90-100 mm

___________

______vely stains with India Ink and nigrosin

Stains with ______ and ___________

Titan

Melanised

Negati

PAS and mucicarmine

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C. neoformans

Frequently isolated from _______ contaminated with ______ or other ______ and NOT in _________________.

soil; pigeon

bird droppings

fresh wet droppings

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C. neoformans

The precise link between C. neoformans and birds to date remains ________.

unclear

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Birds get infected with C. Neoformans

T/F

They do not

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C. gattii

Isolated from _______ in the _____ group of _________ trees, cedar, oak and other native trees.

decaying wood

red gum

eucalyptus

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C. gattii has been isolated from bird droppings.

T/F

C. gattii has not been isolated from bird droppings.

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C. gattii affects _________________ patients

C. neoformans affects _____ patients (98% _________ patients, Rarely ___________)

Immunocompetent

HIV; Immunocompromised; immunocompetent

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C. neoformans var neoformans affects _______________ patients

Immunocompromised; rarely immunocompetent

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Cryptococcosis refer to infections caused by any species of the genus __________.

Cryptococcus spp. are capable of causing diseases in ______________________________________ individuals.

Cryptococcus

both immunocompetent and immunocompromised

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_________ is the most common clinical manifestation of cryptococcosis.

Cryptococcal meningitis

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Disseminated cryptococcal disease is largely associated with ______/_____

HIV/AIDS.

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__________ —————- disease is largely associated with HIV/AIDS.

Disseminated cryptococcal

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Virulence factors of cryptococcus

Polysaccharide capsule formation
Comprised of _________________ (GXM) and _____________ (GalXM)

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glucuronoxylomannan

galactoxylomannan

Virulence factors
Polysaccharide capsule formation

Key roles
Anti-_________
Antibody _____________
Inhibition of ______________
Deregulation of _______________
Interference with ___________________
L-selectin & tumor necrosis factor loss

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phagocytic

unresponsiveness

leucocyte migration

cytokine secretion

antigen presentation

Virulence factors of cryptococcus

Major virulence
__________ formation
________ pigment production
Ability to grow well at ___0C
____________ ————

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Polysaccharide capsule

Melanin; 37

Phenotypic switching

Virulence factors of cryptococcus

Other virulence
Secreted _________________
______ production
Enzymes associated with ________ against _____________

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phospholipase B

Urease

protection

oxidative stresses

Who are at risk?
C. neoformans

_____(80-90%)
Idiopathic CD4 ______
________ malignancies and disorders

Long-term ________ and /or immunosuppressive therapy
_______ and _______ transplant recipients
___________

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HIV; lymphopenia

Lymphoproliferative

corticosteroid

Solid organ & bone marrow

Sarcoidosis

Who are at risk?
C. neoformans

Treatment with _______ antibodies
____________ diseases
Hyper-Ig___ or Hyper-Ig__ syndromes

Decompensated _______disease

_____ failure and /or peritoneal _____

Adult-onset immunodeficiency

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monoclonal

Rheumatological

M; E

chronic liver

Renal; dialysis

Virulence factors of cryptococcus neoformans

Melanin pigment production
Catalyzed by the enzyme ________________

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Phenol oxidase

Virulence factors
Melanin pigment production

Key Roles
Anti________
Cell wall _______ and _______
Interference with ____-cell response

Reduction of susceptibility to antifungal agents
__________ of antibody mediated phagocytosis
Protection from extreme ________

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oxidant
support and integrity
T

Abrogation; temperature

Virulence factors: Phenotypic switching Occurs during ______ infection Common in serotype ____ and ____ strains of C. neoformans Associated with differential ______ and _______ changes in virulence “_______” cell formation

chronic A and D gene expression and capsule Titan

Cryptococcus are _______ encapsulated _____. C.______ and C.____ are the two main species implicated in clinical disease.

ubiquitous; yeasts neoformans; gatti

C. neoformans var. grubii (serotype ___) is the most common cause of ______ disease in HIV/AIDs patients.

A disseminated

C.________ var. ——— (serotype ___) is the most common cause of disseminated disease in HIV/AIDs patients.

neoformans grubii A

Who are at risk: C. gattii Predominantly immuno__________ individuals

competent

Who are at risk: C. gattii Other risk factors1 •HIV (___-___%) •Current ______ •Age (>___ years) •History of ________

10-20 Smoker 50; invasive cancers

Cryptococcus & HIV Cryptococcus is the ____________ leading opportunistic infection in patients with HIV/AIDS. Patients with CD4 <____ are the most at risk.

2nd or 3rd 100

Cryptococcus & HIV Cryptococcus is responsible for up to ____% (13-44%) of the HIV/AIDS deaths. 6% of the global HIV/AIDS population with under _____ CD4 cells are CrAg positive, with substantial geographical variability

100

Cryptococcal disease Cryptococcal infection is associated with a range of illness. In some people, the fungus causes a lung infection similar to ———-, or it can cause ______________. The incubation period is _______, but it is thought that the infection can ____________________________.

tuberculosis; no symptoms at all. not known remain dormant in the body for many years

Cryptococcal disease In immunosuppressed people , particularly HIV-infected people with CD4 counts under 100, the infection can _____ and ____________________. Cryptococcal _______, most common presentation.

reactivate spread throughout the body Meningitis

Clinical Presentations Cryptococcal Meningitis Typical : _______ onset of fever and headache ________ and/or meningeal signs in only 25%

Subacute Photophobia

Clinical Presentations Cryptococcal Meningitis Less typical •_______ •__________ • Progressive _______ • __________ impairment • FUO

Seizures Confusion dementia Visual or hearing

Investigations of CNS Cryptococcal infection Csf sample ______ ml volume needed ____eased yield if multiple CSF samples

3 - 5 incr

Investigations of CNS Cryptococcal infection Csf examination Measure opening pressure (OP): • 50% of HIV+ patients have OP >_____ cmH20 • (Raised Or Lowered?) lymphocytes •(Raised or Lowered?) protein •(Low or High?) glucose Indian Ink & fungal culture & CRAG

25 Raised Raised Low

Summary of Diagnostic Options Culture ____________ colonies within 48hours _______ cultures often (+) in immunosuppressed patients 2/3rds with _________ • Tissue _______ or ______ stain ________ for CSF •Cryptococcal antigen Serum and CSF are 99% sensitive in _____ patients Serum is (more or less?) sensitive in normal hosts

White mucoid Blood Meningitis Silver or mucicarmine India ink AIDS Less

Cryptococcal meningitis is a common cause of death among HIV/AIDS patients T/F

In some areas of the world, cryptococcal meningitis is estimated to cause more deaths than tuberculosis (TB) T/F

Fungal Meningitis- Cryptococcus Flashcards

(41 cards)