Microbiology Fungal Infections Flashcards Preview

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Flashcards in Microbiology Fungal Infections Deck (32):
1

Pathogenic fungi:

• > 1000,000 fungal species
• >1,5000 new species each year
• >600 species reported from infections
• 200 on regular basis
• One new emerging ‘pathogen’ each month!!

2

Mycosis

Infection caused by fungi

3

Mycotoxicosis

Condition resulting from ingestion of food contaminated with metabolic products of Fungi

4

Description of fungi

Eukaryotic cells, but distinct from plants and animals

5

Fungi Types

Yeasts – single oval cells
Moulds- tube like cells (hyphae) and multicelled structures

6

Fungi Produce

Spores (used for identification)

7

How you get a fungal infection

1. Exogenous
2. Own source
3. Traumatic implantation

8

Fungal infection types

• Superficial (derma)
• Subcutaneous (infection seen)
Systemic (seen in immunosuppressed patients)

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Superficial fungal infection: Types and targets

Dermatophytes: skin, hair and Nails
Candidosis: Skin, Nail and Mucous membranes
Pityriaisis versicolor: Skin

10

Dermatophytes sources

Anthropophilic – Man
Zoophilic (animals)
Geophilic( Soil)

11

Dermatophytes: Trichophyton causes

Athletes foot
Cattle Ring worm
Scalp ringworm but can have bacterial infiltrations

12

Dermatophytes: Trichophyton causes size

Small in comparison

13

Dermatophytes Microsporum size

Large spores, thick walls

14

Dermatophytes Microsporum Causes

Microsporum canis (cat ringworm)
Aldwanee: only seen on prepubescent

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Dermatophytes epidermophyton floccosum causes

Athletes foot

16

Dermatophyte Malassezia furfur description

Yeast (lipid loving)
Carried in fatty Layer (greasy areas of skin)
Can cause nasty rashes

17

Superficial Candidosis

Mucosal infection
Chronic mucocutaneous candidosis
Nail infection
Cutaneous infection
Seen in poorly managed diabetes/Wet hands occupation related

18

Subcutaneous Infection Severe disease

Mycotoma – caused by funga growth which late stage erodes tissue and bone. Requires amputation.

19

Deep fungal Infection: Description

Large numbers of potential aetiological agents, most of which are ubiquitous environmental organisms

20

Deep fungal Infection: Acquired through

Inhalation

21

Deep fungal Infection: Common in

It’s a Life threatening disseminating infection, common in immunocomprimised patients

22

Deep fungal Infection: Examples

Mucoromycosis
Cryptpcococcosis
Candidosis
Aspergillosis

23

Mucoromycosis

White fluff mould on fruit
Colonises face
Very Rapid spread – no crosswalls or septae therefore fast transfer of nutrients

24

Mucoromycosis Rx

Fast acting anti-fungal (amphotericin)

25

Cryptococcosos

Fungal Meningitis (large polysaccarhide coat which may help with transfer.

26

Invasice candidosis

Most common deep fungal infection
Numerous manifestations, but few specific clinical signs

27

Invasice candidosis clinical signs

Oesophageal infection
Endocarditis
Disseminated candidosis
Osteomyelitis

28

Asperillosis

Omychomycosis (superficial)
Cutaneous lesion
Otitis externa (ear)
Keratitis
Aspergilloma (invasive)

29

Critical Factors for Successful treatment of Invasive fungal infection:

1. Prompt recognition – few specific clinical signs difficult to diagnose
2. Aggressive antifungal treatment
3. Surgical resection of lesions?
4. Reversal of immunosuppressions

30

Diagnosis

Direct microscopy
Culture and ID
Serology – antibodies and antigens
Molecular ID

31

Antifungals:

Echinocandins
Polyenes (1mg/kg)
Azoles
Allylamines
Flucytosine
Griseofulvin

32

4 targets of anti-fungals:

1. Cell wall
2. Ergosterol
3. Pyrimidine
4. Spinder cell formation

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