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Flashcards in Immunology and Pathology Deck (106)
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1

What are extremophiles?

Microorganisms adapted to live in harsh and extreme environments

2

What are thermophiles?

Bacteria with optimum growth temp >45

3

What are psychrophiles?

Bacteria with optimum growth temp below 20

4

What are bacteria that withstand high osmotic pressure environments called?

Halophiles - high salt environments and spoilage of salted foods

5

What are bacteria that live in acidic and alkaline environments called?

Acidophiles
Basophiles

6

What are the 7 beneficial activities of microorganisms?

1. Environmental cycles: C, N, O, S
2. Agriculture and horticulture
3. Food and drink: brewing, wine-making, baking, cheese
4. Medicine: insulin, antibiotics
5. Energy production: ethanol, methane, H2
6. Solvent production: acetone, butanol
7. Nutritional benefits and protective in man and animal

7

What are the 7 mechanical antimicrobial factors which microbiota must contend with in healthy host?

1. Flushing action of liquids: saliva, urine
2. Peristalsis of gut
3. Skin: impermeable barrier
4. Cough/sneeze reflex
5. Mucus
6. Cilia
7. Shedding of epithelial cells

8

What are the 8 biochemical antimicrobial factors in health?

1. Anaerobicity
2. Acidity
3. Sebaceous secretions
4. Sweat: high salt
5. Lysozyme: antibacterial enzyme
6. Digestive enzymes
7. Bile: detergent action
8. Colonisation resistance

9

What are the 6 immunological antimicrobial factors in health?

1. Complement
2. Phagocytosis
3. Inflammation
4. Acute phase response
5. Antibodies
6. Cell-mediated responses

10

Why is infection control important?

Body surfaces are heavily colonised
Inanimate surfaces, instruments, H2O, air contaminated
Patients and staff may be carrying infections
Need to protect patients and staff from risk of infection
Dentists have responsibility for ensuring safety

11

What are some of the infection control procedures?

Hep B immunisation
Sterile instruments/equipment
Proper aseptic techniques
Safe disposal of waste
PPE
General hygiene and cleanliness

12

What dental diseases are caused by microorganisms?

Dental plaque related disease: caries, periodontal disease
Other oral infections: abscess, mucosal infections, bone and sinus infections
Systemic disease: infective endocarditis, brain abscess

13

What are the 5 infectious agents in inc. complexity?

1. Prions: infectious proteins
2. Viruses: non-living, obligate intra-cellular parasites
3. Bacteria: prokaryote
4. Fungi: eukaryote
5. Protozoa: eukaryote

14

What are prokaryotes?

Single-celled, contain RNA and DNA
Lack membrane bound nucleus
Single, circular DNA molecule as chromosome

15

Describe eukaryotes

Truly nucleated: uni/multicellular containing both RNA and DNA
Membrane bound nucleus and other organelles

16

What are prokaryotes and eukaryotes but viruses not?

Defined as living organisms

17

What are parasites?

Organism that lives in/on 2nd organism (host)
May have little/no harmful affect, in apparent or bring about damage/harm (pathogen)

18

What are commensals?

Microbes found colonising host that benefit or are essential to them

19

Describe bacteria

Unicellular
Reproduce asexually by binary fission

V small, v diverse (aerobes, anaerobes, microaerophilic, capnophilic)
Low generation time (mins)

20

What are the 2 important structural features of bacteria essential for their survival?

1. Fimbriae: on surface; protect against phagocytosis, aid adherence to target
2. Pilus: share genetic material; antibiotic resistance

21

What are the 6 main bacteria types that interact with man?

1. Gram +ve
2. Gram -ve
3. Acid-fast
4. Mycoplasma, ureaplasma
5. Rickettsiae
6. Chlamydia

22

Describe gram +ve bacteria

Thick peptidoglycan cell wall, possible protein layers, stain purple

23

Describe gram -ve bacteria

Thin peptidoglycan layer, 2nd membrane, periplasm (space), lipid rich, fragile, stain pink

24

What are acid-fast bacteria?

Bacteria with mycolic acids (waxy lipid) attached to peptidoglycan
Cross linking with arabinose and galactose
Does not stain by normal procedure

25

What is special about mycoplasma and ureaplasma?

Cytoplasmic contents surrounded by well developed PM thus resistance to antibiotics that target cell wall e.g. penicillins

26

How do viruses replicate?

Depend on host
Adsorption
Penetration
Assembly
Reslease

27

How do fungi reproduce?

Asexual - most freq. in good conditions
Sexual - fusion of gametes or gametangia

28

How do yeasts reproduce?

By budding

29

What is an important yeast in oral biology?

Candida albicans

30

When are the body surfaces sterile?

Immediately before birth, rapidly colonised after birth