Fungal Pathogens L14

Question 1

what do eukaryotic fungi contain

Answer 1

nucleus

nuclear membrane

Question 2

what can happen in eukaryotic fungi

Answer 2

mitosis

Question 3

what are saprophytic fungi

Answer 3

live on dead / decaying material

not causing disease

Question 4

what is parasitic fungi

Answer 4

live on another organism at its expense

Question 5

what is the fungal cell wall like

Answer 5

Firm polysaccharide structure

Question 6

what is fungal cell wall similar to

Answer 6

similar to higher plants / animals

Question 7

what is fungi cell wall made of

Answer 7

cellulose

chitin

Question 8

what are hyphae

Answer 8

long filamentous structures grow on surface of food

Question 9

what may fungal cell walls exist as

Answer 9

single cells (yeasts) or as connecting filaments or hyphae (moulds)

Question 10

which are bigger fungi or bacteria

Answer 10

fungi

Question 11

what nucleus do fungi have

Answer 11

eukaryotic

Question 12

what nucleus do bacteria have

Answer 12

prokaryotic

Question 13

what is in the cytoplasm of fungi

Answer 13

mitrochondria

ER etc

Question 14

what is in the cytoplasm of bacteria

Answer 14

no organelles

Question 15

what is the bacteria cell wall

Answer 15

muramic acid

Question 16

is dimorphism present in fungi

Answer 16

may be present

Question 17

is dimorphism present in bacteria

Answer 17

never

Question 18

how do fungal moulds grow

Answer 18

Grow by elongation or lateral branching

Question 19

how do fungal yeasts grow

Answer 19

budding

Question 20

how does fungal reproduce

Answer 20

asexual

sexual

Question 21

what is asexual fungal reproduction

Answer 21

Dissemination of spores singly or in multitudes from specialised structures

Question 22

what is sexual fungal reproduction

Answer 22

fungi are haploid – meiosis takes place following fusion

Question 23

can we inhale spores

Answer 23

Form spores as a reproductive state

Spores spread in air, we can inhale these spores as they disseminate

Question 24

what are the yeasts

Answer 24

Spherical, often budding

Question 25

example of yeast

Answer 25

Cryptococcus neoformans

Question 26

what are yeast-like fungi

Answer 26

yeasts but elongated, pseudomycelia may be seen

Question 27

example of yeast-like

Answer 27

Candida albicans

Question 28

what are filamentous fungi

Answer 28

form a carpet or layer (mould)

Question 29

examples are filamentous fungi

Answer 29

Aspergillus fumigatus

Question 30

what are dimorphic fungi

Answer 30

may exist as yeasts or filamentous forms

Question 31

examples of dimorphic fungi

Answer 31

Histoplasma capsulatum

Question 32

what is considered in medically important dungi

Answer 32

frequency pathogenicity therapeutics

Question 33

what is frequency of medically-important fungi

Answer 33

extremely common infections

Question 34

examples of frequent medical-important fungi

Answer 34

candidiasis and ringworm

Question 35

what is pathogenicity of medically-important fungi

Answer 35

some are highly pathogenic

Question 36

examples of high pathogenicity medical fungi

Answer 36

e.g. Histoplasma or cause significant mortality in the immunocompromised e.g. Aspergillus fumigatus

Question 37

what is therapeutics in medical fungi

Answer 37

treatment options are limited compared to bacterial infections

Question 38

can fungi cause problems

Answer 38

Generally fungal infections don’t cause problems, can be very serious in those that are immunosuppressed

Question 39

how are superficial diseases caused by fungi

Answer 39

hair, nails, mucous membranes – changes in host resistance and normal flora, or physical contact

Question 40

how are subcutaneous diseases caused by fungi

Answer 40

skin or deeper tissues, often from soil e.g. Sporothrix schenckii. Commoner in developing world

Question 41

how are systemic diseases caused by fungi

Answer 41

inhalation e.g. spores → If in lungs can cause pneumonia then can invade bloodstream (candida)

Question 42

are diseases caused by fungi transmissible

Answer 42

Some are transmissible from person-to-person contact – superficial ones, not too serious

Question 43

how can fungal diseases be diagnosed

Answer 43

``` clinical suspicion microscopy culture histology antibody/antigen ```

Question 44

how are fungal diseases diagnosed via clinical suspicion

Answer 44

e.g. fever unresponsive to antibacterials. Meningitis or pneumonia in the immunocompromised

Question 45

how are fungal diseases diagnosed via microscopy

Answer 45

Gram’s stain, India ink, wet prep

Question 46

how are fungal diseases diagnosed via culture

Answer 46

Sabouraud’s agar, Neutral glucose peptone agar +/- chloramphenicol

Question 47

how are fungal diseases diagnosed via histology

Answer 47

Grocott’s stain

Question 48

how are fungal diseases diagnosed via antibody/antigen

Answer 48

candida/aspergillus precipitins; galactomannan

Question 49

what happens in superficial infection fungal diagnosis

Answer 49

skin scrapings for microscopy (KOH – make skin cells translucent can see if fungal cells there) and culture

Question 50

what happens in systemic infections fungal diagnosis

Answer 50

blood cultures, grow bacteria from the blood. tissue (e.g. lung biopsy), serology or antigen detection (more invasive techniques)

Question 51

what are yeast-like fungi part of

Answer 51

GI and respiratory flora

Question 52

what are the yeast-like fungi like

Answer 52

Opportunistic pathogens

Question 53

what are the yeast-like structures overgrowth/infection predisposed by

Answer 53

``` diabetes mellitus malignancy defects in CMI trauma drugs ```

Question 54

what does diabetes mellitus cause

Answer 54

these organisms cause a problem, will grow on sugar as a nutrient and use it

Question 55

what is malignancy

Answer 55

immunosuppressant therapy

Question 56

what is CMI

Answer 56

cell mediated immunity

Question 57

what is the effect of CMI defects

Answer 57

don’t have functioning phagocytic cells, so organisms can overgrown and cause problem

Question 58

what can trauma cause

Answer 58

organisms may be pushed into different sites

Question 59

what do ringworms infect

Answer 59

keratinous tissues of the hair, nails and skin, uses the keratin

Question 60

are ringworms contagious

Answer 60

only contagious mycosis from humans or animals | Animals and humans get infected can infect each other vice versa

Question 61

how are ringworms diagnosed

Answer 61

clinical, scrapings for microscopy and culture

Question 62

what is the treatment of ringworms

Answer 62

clotrimazole, terbinafine

Question 63

what do filamentous fungi have

Answer 63

Ubiquitous spores (all over the place) – soil, dust (building work)

Question 64

what clinical illnesses do filamentous fungi cause

Answer 64

pulmonary systemic other e.g. sinusitis

Question 65

what causes the pulmonary clinical illnesses - filamentous fungi

Answer 65

breathe in spore and can cause asthma, if starts to grow in the lung can cause fungal ball which can lead to invasive aspergillosis and into blood stream so around the body to e.g. brain

Question 66

examples of pulmonary clinical illness - filamentous fungi

Answer 66

Asthma (Bronchopulmonary aspergillosis [ABPA]) Aspergilloma (fungal ball) Invasive aspergillosis

Question 67

examples of systemic clinical illness - filamentous fungi

Answer 67

Lung, renal, cerebral (immunocompromised)

Question 68

with Cryptococcus neoformans where is it found

Answer 68

Environmental organism: soil, bird droppings

Question 69

what is Cryptococcus neoformans

Answer 69

true yeast | opportunistic pathogen

Question 70

what is the clinical problem that Cryptococcus neoformans cause

Answer 70

meningitis in HIV / cancer patients; pulmonary disease (pneumonia / nodules); disseminated

Question 71

what does Cryptococcus neoformans cause

Answer 71

defects in CMI

Question 72

how is Cryptococcus neoformans diagnosed

Answer 72

clinical suspicion microscopy culture antigen detection

Question 73

how is Cryptococcus neoformans clinical suspicion diagnosed

Answer 73

(signs + symptoms; e.g. meningitis in an HIV patient)

Question 74

how is Cryptococcus neoformans microscopy diagnosed

Answer 74

India Ink stain on CSF

Question 75

how is Cryptococcus neoformans culture diagnosed

Answer 75

CSF, blood

Question 76

how is Cryptococcus neoformans antigen detection

Answer 76

CSF, blood

Question 77

what do dimorphic fungi exist as

Answer 77

a mould in the environment; but as a yeast in tissues

Question 78

how are histoplasma capsulatum detected

Answer 78

Xray detect in lungs | Lower temp form filamentous structures