Fungi

• Summarise briefly the ecology and epidemiology of infectious fungi

tinea...

spore dispersal

FUNGAL DISEASE

Allergies (due to spores)

capitis = head

pedis = foot

corporis = body

cruris = groin

unguium = nail

rhinitis

ABPA

spores

dermatitis

asthma

Subcutaneous Mycoses

Superfical Mycoses

traumatic inplantation

RARE

skin or nail shafts

James Gutsell

no living tissue no cellular response

chronic skin and subcut infection

Sporotrichosis

Chromoblastomycosis

Mycetoma

Cutaneous Mycoses

examples; black and white piedra

pityriasis versicolor

Tinea nigra

eat keratin

dermatophytes / keratinophilic fungi

LEARNING OBJECTIVES FROM MCD

host response to biproducts

Fungal disease

diverse morphology

Candida

• Outline the main differences between fungi and bacteria

inflammation

C. albicans = opportunistic commensal

Mycoses

• Allergies
• Mycotoxicoses (poisoning)
• Mycoses (infections)

(infections)

• List the major groups of pathogenic fungi and their growth forms

gut surgery, chemo and catheters

• Define "superficial mycoses" and "deep mycoses", with examples

immunocompromise

systemic

cutaneous

superficial

• Describe briefly the main classes of antifungal agents

superficial, mucosal and systemic infection

increasing severity

Systemic Mycoses

Cryptococcus

Candida

Fungal characteristics

primary vs. opportunisitic

Aspergillus

ABPA

Aspergillus

invasive pulmonary aspergillosis

• contain membrane-bound nuclei and organelles

A. fumigatus = 90% disease

nothing!

Mycotoxicoses

asthma

Others!

• lack chloroplasts

Histoplasma, Blastomyces etc

immunocompromise

multicellular filamentous fungi (not yeast!)

Increasing due to;

normal host

Mycotoxin: "secondary metabolites of moulds that exert toxic effects on animals and humans"

• cell walls comprising glucans and chitin

Aspergillus

range of disease dependent on host response

More ICU admissions

• cell membrane contains ergosterol

E.g. penicillin and aphlatoxin

Organ/haem transplants

cavitatory lung disease

chronic lung disease

major risk factors: neutropenia, transplants (esp lung and HSCT), leukaemia, AIDS

• some are dimorphic (yeast or hyphae)

Early: breathing problems, D&V, dehydration

Indwelling lines/devices

aspergilloma

chronic necrotising aspergillosis

• versatile with respect to environment

Later: hepatic and renal failure

HIV/AIDS

Cryptococcus

C. neoformans = encapsulated yeast (other species too)

most lethal infection in AIDS (meningitis)

survives in environment (pigeons, eucalyptus)

very high mortality (epecially in sub-Saharan Africa)

Anti-fungals

Diagnosis

Take a swab/blood/CSF

Culture it

Microscopy

PCR

Cell membrane

DNA/RNA

synthesis

Cell wall

Thank you,

(ergosterol cf cholesterol)

new Ab/Ag asssays - glucan, mannan etc

Azoles

any questions?

inhibit 1,3- glucan synthase

Anything ending in 'zole'...

• Ketoconazole
• Itraconazole
• Fluconazole
• Voriconazole

Caspofungin

Echinocandins

Flucytosine

pyrimidine analogue,

inhibits DNA and RNA synthesis

Amphoteracin B

Nystatin

Polyenes